40 Winning Plants for Shade

Hosta Photo by Maria Gulley

Hosta
Photo by Maria Gulley

Many of us have yards with shaded areas, but I get a lot of questions asking what the plant options are beyond hostas. Don't get me wrong, I love hostas - there are so many unique varieties, and bees and hummingbirds can't get enough of the flowers. But they are prone to slug and deer damage, and it's not crazy to want a little bit of something different. Below I've come up with 40 different plants for shade - some prefer dappled sunlight, and others can take pretty dense shade. I divided the plants into four categories: shrubs and small trees, perennials, groundcovers, and annuals and tropicals.

Some of the plants that people often pick for shade have been deliberately omitted due to having invasive tendencies (wintercreeper, English ivy), being poorly matched for central Indiana growing conditions (azalea, rhododendron), or other reasons. With the plants that remain, I did my best to pick many different colors and styles. All of these plants should be available for retail purchase, although some may be easier to find at independent garden centers rather than big box stores. If you have a specific need you're trying to fill, never hesitate to ask! I love a good plant selection challenge. Since I'm a bit of a native plant and pollinator nerd, I'm marking species native to Indiana with a * and pollinator-friendly species with a + .

Shrubs and Small Trees

Bottlebrush Buckeye (Aesculus parviflora)*+: a large, showy-flowered shrub that tends to form a sprawling colony

Boxwood (Buxus species and hybrids): this evergreen has some shade-tolerant varieties, although they will be less dense in the shade than in the sun

Chokeberry (Aronia species and hybrids)*+: known for its brilliant fall color, this medium sized native shrub also sports edible berries and small white flowers

Coralberry (Symphoricarpos orbiculatus)*: a lesser known and harder-to-find shrub, coralberry is a low-growing suckering shrub that is perfect for filling low-maintenance areas; white, pink, or red berries in the fall

Japanese Maple (Acer palmatum): there is a Japanese maple for every situation, with a wide range of sizes, habits, leaf colors, and leaf shapes; some varieties are more shade tolerant than others

Oakleaf Hydrangea (Hydrangea quercifolia)+: a reliable, low-maintenance shrub with amazing flowers; both dwarf and large varieties available; good dark red fall leaf color

Pawpaw (Asimina triloba)*+: a.k.a. Indiana banana, this isn't the showiest tree but it's a good understory filler that makes delicious fruits

Serviceberry (Amelanchier species and hybrids)*+: showy white flowers, delicious early summer berries, and fantastic fall color make this small tree a winner

Virginia Sweetspire (Itea virginica)*+: sweet-smelling white flowers and a tolerance for dense shade make this small shrub perfect for shady back yards

Witchhazel (Hamamelis vernalis): this shrub has some of the earliest blooms in the garden with color starting as early as February; there are also varieties that bloom late in the fall around November

Perennials

Astilbe (Astilbe species and hybrids)+: one of my favorites for shade, astilbe has bright feathery plumes of flowers in a range of reds, pinks, whites, and purples

Ferns (such as Cinnamon, Christmas, Autumn): ferns on the whole thrive in shade, and several do quite well in central Indiana; two of our favorites are cinnamon fern and autumn fern

Bleeding Heart (Dicentra species and hybrids)+: with a unique flower and convenient spring bloom time, bleeding heart is an old-fashioned favorite that's regaining popularity

Coral Bells/Foamflower/Hybrids (HeucheraTiarella, and Heucherella varieties)*+: these closely related native species and hybrids come in a range of leaf colors and sizes; they're perfect for getting a warm color palette in the shade

Ice Dance Sedge (Carex morrowii 'Ice Dance'): if you love grasses but have lots of shade, sedges are for you; Ice Dance Sedge has the tamest appearance and its white variegation helps it stand out

Epimedium (Epimedium species and hybrids): I consider this fascinating plant one of the most underused perennials; the spring flowers come in amazing shapes, and the foliage changes color through the year and can be evergreen in mild winters

Japanese Forest Grass (Hakonechloa macra): another pick for grass-lovers, this one comes in greens and golds, and it waves beautifully in the lightest breeze

Lenten Rose (Helleborus species and hybrids): with a February to March bloom season and evergreen foliage, Lenten rose delights year round; be careful around kids though - it's poisonous

Ligularia (Ligularia species)+: the dramatic large foliage (nearly black on some varieties) is matched only by the brilliant yellow flowers that shoot up on spikes in mid summer

Pulmonaria (Pulmonaria longifolia): a low-growing foliage plant with a humble spring flower and interesting spotted patterns of variegation

Snakeroot (Actaea racemosa)*+: with leaves 2-3' tall and white flower spikes up to 6', snakeroot can fill space easily in a shade garden

Toad Lily (Tricyrtis hirta)+: toad lily has fascinating speckled flowers and a late summer/early fall bloom time that keeps the color coming after most plants are done for the year

Astilbe Photo by Maria Gulley

Astilbe
Photo by Maria Gulley

Bleeding Heart Photo by Maria Gulley

Bleeding Heart
Photo by Maria Gulley

Japanese Forest Grass Photo by Maria Gulley

Japanese Forest Grass
Photo by Maria Gulley

Toad Lily Photo by Maria Gulley

Toad Lily
Photo by Maria Gulley

Groundcovers

Ajuga (Ajuga reptans)+: purple flowers in the spring are a special treat, but the low-growing foliage is a delight all year long

Bigroot Geranium (Geranium macrorrhizum)+: there are many kinds of perennial geranium, but only certain species and hybrids are adapted for shade; be sure to check the tag before picking one

Mondo Grass (Ophiopogon japonicus): this short, spreading, grass-like groundcover comes in green and a deep purple that approaches black

Lily-of-the-Valley (Convallaria majalis): another old-fashioned favorite for its sweet-smelling white flowers, lily-of-the-valley is another poisonous pick to avoid if you have small children

Pachysandra (Pachysandra procumbens* and terminalis): in addition to the more readily available Japanese pachysandra, there is also a native species; both are evergreen

Solomon's Seal (Polygonatum odoratum)+: the arching stems and identical oval-shaped leaves are the show-stoppers here, but you'll also find hanging white flowers in pairs in the spring

Wild Ginger (Asarum canadense* and europaeum): another underrated superstar, you can find wild ginger in a glossy European variety or a more plain North American species; both are low-maintenance and trouble-free

Wood Phlox (Phlox divaricata)*+: this native shade phlox is a little trickier to find in garden centers, but its pale blue flowers and popularity with all manner of pollinators make it worth the hunt

Pulmonaria Photo by Maria Gulley

Pulmonaria
Photo by Maria Gulley

Lily-of-the-valley Photo by Maria Gulley

Lily-of-the-valley
Photo by Maria Gulley

Solomon's Seal Photo by Maria Gulley

Solomon's Seal
Photo by Maria Gulley

Annuals and Tropicals

Begonia (Begonia species and hybrids): begonias are faithful, tried, and true; many varieties work in both sun and shade, so if you want consistency this is a great pick

Caladium (Caladium bicolor): sometimes called elephant ears (that name is more often used for other plants), these delicate foliage plants come with foliage in all kinds of patterns of green, white, pink, and red

Coleus (Solenostemon species)+: there is a coleus for every occasion, including some that take full sun as well as full shade; this leafy plant comes in oranges, red, yellows, greens, and combinations of all of the above

Cordyline (Cordyline): also known a ti plant, cordyline is a tropical foliage plant that likes light shade; it's a good upright plant to fill space in containers

Creeping Jenny (Lysimachia nummularia): this is currently my favorite trailing plant for containers, and it can also be used as a groundcover; the foliage is an almost yellow lime green in sunnier spots and more green in the shade

Lobelia (Lobelia erinus)+: lobelia offers one of the only true blues in the landscape, and it loves shade; it's a popular pick as a bedding plant or to fill little nooks and crannies in planters

New Guinea Impatiens (Impatiens hawkeri): I left non-new guinea impatiens off the list since impatiens downy mildew has become a major problem, but their cousins New Guinea impatiens aren't susceptible to the disease

Persian Shield (Strobilanthes dyerianus): silvery purple foliage with dark green veins stand on stems that grow to over three feet tall on this stunning shade annual

Philodendron (Philodendron species): there are many kinds of philodendron, but all of them can take the shade; they are also popular houseplants, so bring them inside overwinter to keep a little bit of green in your life

Wishbone Flower (Torenia fournieri)+: another good bedding plant option, torenia comes in purple, pink, blue, white and yellow

Lobelia and Japanese Forest Grass Photo by Maria Gulley

Lobelia and Japanese Forest Grass
Photo by Maria Gulley

Coleus and Creeping Jenny Photo by Maria Gulley

Coleus and Creeping Jenny
Photo by Maria Gulley

Persian Shield By Montréalais - Own work, CC BY 3.0

Persian Shield
By Montréalais - Own work, CC BY 3.0


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August: Wild Ginger

This month we meet a hardy groundcover for shaded properties: wild ginger. The gingery-smelling roots are edible and do have a ginger-like taste, although they are not closely related to true ginger. But mostly they are valued for forming dense, attractive green carpets, and the North American species is valued as a native groundcover.

Canadian wild ginger has larger, almost velvety leaves.  By Michael Wolf - Own work, CC BY-SA 3.0

Canadian wild ginger has larger, almost velvety leaves.
By Michael Wolf - Own work, CC BY-SA 3.0

We use both European wild ginger and American wild ginger in the landscape, although it does take some work to find them. Currently it’s easier to find the glossier European species, but as interest in native species grows, the Canadian variety is showing up in more places as well. The small, bell-shaped flowers are pollinated by flies, and they bloom on the ground underneath the leaves. They are only visible by pulling the leaves back.

European wild ginger has smaller, glossy leaves.  By Stefan.lefnaer - Own work, CC BY-SA 4.0

European wild ginger has smaller, glossy leaves. By Stefan.lefnaer - Own work, CC BY-SA 4.0

Common Name: Wild Ginger

Scientific Name: Asarum canadense and europaeum

Light: full to partial shade

Size: 3-6” tall, 12-18” wide

Bloom Time and Color: small, maroon flowers grow underneath the leaves in spring

Notable Varieties: no cultivated varieties, just the two straight species

Soil: prefers consistent moisture

Other Notes: tolerates very deep shade, deer resistant

See other plants of the month.



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Pest Alert: Spider Mites

Hot, dry summers stress plants out, and some pests take that as an opportunity to strike. One common pest in the height of the summer is the spider mite, a tiny, spider-like mite that sucks water and nutrients from the undersides of leaves.

Yellow stippling is a symptom of spider mite damage.  By Rasbak - Own work, CC BY-SA 3.0

Yellow stippling is a symptom of spider mite damage.
By Rasbak - Own work, CC BY-SA 3.0

How do I tell if I have spider mites?

There are a handful of different species of spider mites, some of which specialize on just a few plants while others attack a broad range, but the symptoms and treatments are all similar, so we’ll group them together. The first thing you’ll notice in a spider mite infestation is that the leaves of your plants will be covered in tiny yellow dots. If the infestation is bad enough, you may eventually have more yellow or bronze than green on the leaves. When spruces and other needle-bearing plants have a mite infestation, they look kind of dusty, like there’s a film of brown over the needles.

If you flip a leaf over, you’ll see the mites themselves as little orange specks. To see if they’re still alive and active, hold a white sheet of paper under the plant and shake it vigorously to knock some mites off. They will crawl around on the paper after being knocked off if they are still alive and eating your plants. In especially bad infestations, you’ll also see some webbing on the leaves.

What do they do to my plants?

Spider mites suck the moisture from your plants leaving an unattractive appearance and stressing the plants out. Since they tend to be a worse problem when plants are already experiencing drought stress, serious infestations can cause leaf loss, stunting, or even death in smaller plants, and they can leave larger plants more vulnerable to additional problems. In a healthy plant, a mild to moderate infestation is no serious problem, but if it spirals out of control in a stressed landscape you’ll need to start to worry.

What can I do to get rid of them?

In serious infestations, leaves become stunted and the mites start to create webs.  By Rasbak - Own work, CC BY-SA 3.0

In serious infestations, leaves become stunted and the mites start to create webs.
By Rasbak - Own work, CC BY-SA 3.0

The best treatment is prevention. Spider mites have a whole host of natural enemies, so the best thing you can do to control them is to avoid using pesticides on your plants unless your are actively controlling another harmful pest problem. Excessive or inappropriate pesticide use actually creates more problems than it solves. Mites aren’t killed by many common insecticides, so they will survive while their predators are killed off if you use chemicals without having an actual need for them.

Since drought increases the threat of spider mites, keeping your landscape watered during serious dry spells can help protect them, and it can help reduce problems if mites have already invaded. For tips on keeping your landscape happily watered, check out last week’s blog post.

But if you already have an infestation, there are some steps you can take. Mites don’t move very fast or very far, so spraying plants with a strong setting on your hose can knock them off as long as you’re targeting the undersides of the leaves. Start with lower pressure on more delicate leaves and check to see if the pests are knocked off so that you don’t damage the leaves with the water. Since there may be eggs left behind or some mites may hold on tighter, you might need to spray the plants down weekly or twice a week while hot, dry weather persists.

In widespread, intense cases, chemicals may be necessary. Insecticidal soaps and horticultural oils work on spider mites during the growing season. Dormant oils can be used in the winter to smother the adults that overwinter on the branches. Miticides designed specifically to kill mites do exist, but they must be applied by a state licensed professional. If you think chemical action may be warranted, it’s not a bad idea to contact a professional or submit a sample to the Purdue Plant and Pest Diagnostic Lab first to get customized instructions for your situation. We are happy to help! If you want more information or to see more pictures, Purdue and Ohio State have excellent resources that go into more detail.

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Tips for Effective Watering

What is the single most important factor in the short-term and long-term success of a new planting? If you said proper watering, you're right. Newly installed plants don't have extensive root systems like more established plants, so they rely on the moisture present in their root ball. Even drought-tolerant species will need a little help at first. As new plants grow and root out into the surrounding soil, they become stronger and more resilient to changes in moisture levels. But be careful - there is such a thing as too much water, especially in the slow-draining clay soils common in the Indianapolis area. Also be aware that just because the hose is running, it doesn't mean that the right amount of water is going to the right place. Follow these instructions to make sure your new installation is happy and healthy.
 

When to water

Dig into the soil 2-4 inches with your hand or a trowel. If the soil feels damp, don’t water, but check the soil daily to see if it's dry. Soon you will be able to use the weather and the look of the plant will help you judge if it’s time to check the soil again so you aren’t having to check every day. If it's 90 degrees in July, and it hasn't rained in three weeks, a new tree or shrub might need to be checked twice per week, while perennials should be checked every 2-3 days. If it's 60 degrees in April and it has poured rain for a week, you should be fine checking once per week at most. Eventually, you'll learn what your property needs, and you may not need to dig into the ground often at all.
 

How to water

When the soil is dry, water the plant slowly and deeply. This means you should water slow enough that the water is absorbed without running off. Leaving the hose running on full blast at the base of a tree won't help much because the water will run off instead of soaking into the soil. Instead, leave the hose on a trickle within the root ball of a tree or shrub or set up a sprinkler to cover the area with new plants.

Periodic deep watering is better than frequent shallow watering because it encourages the roots to grow further, and so it prepares the plants to be stronger and more resilient after you stop hand-watering.

Fifteen to twenty minutes of gentle watering should be enough for a shrub or very small tree. For larger trees, water the tree for a total of about 45 minutes, moving the hose once or twice to make sure the root area is evenly covered (you don’t have to move it if you’re using a sprinkler). Tree irrigation bags can be helpful in the short run if you know you'll forget to water a tree. Follow the instructions provided with the bag to make sure you're providing the right amount of water for the size of your tree. In very hot, sunny weather, tree bags can actually hurt your tree by trapping heat and humidity against the bark. In these conditions, consider removing the bag entirely or at least taking it off between fillings.

watering-can-2691568_1920.jpg

Annuals and perennials don't need to be watered as deeply as trees and shrubs since their roots are shallower. A sprinkler or a hand-held hose nozzle works well. 20-30 minutes is usually enough time for a sprinkler on perennials, 10-15 minutes for annuals. When hand-watering, I like to slowly move over the area in 15-30 circuits depending on how dry the soil is. Annuals will need water more frequently than perennials, because we focus more on growing those for a showy display above ground rather than a durable root system below ground.

Keep in mind that all these numbers for watering frequency and duration will change depending on soil type and moisture and weather conditions. When in doubt, check the soil in the way we described above.

Water newly planted trees and shrubs throughout the first year from spring until late fall. Trees benefit from an additional season of watering, especially if they were planted late in the year. Perennials are usually safe to stop watering after 2-3 months, but keep an eye on them. Annuals should be watered all season long. Temporary irrigation can be installed for the first few months or the first season so you don't have to worry about checking the soil. If you’re interested in having temporary irrigation installed after your project is complete, talk to your account manager. Water plants in later years when they look wilted, such as during droughts.
 

Other Tips

  • Water between late evening and early morning to reduce water loss through evaporation (but don't wait if a plant is wilting now!).

  • Avoid watering the leaves when possible. This can cause leaf spot diseases on some plants, especially roses.

  • Frequent light watering is only good for annuals, and even they prefer deeper watering.

  • Wilted leaves can come from too much water as well as from too little water. Always check the soil, especially in containers without drainage.

  • A thick layer of mulch will help conserve moisture. Just make sure you apply extra water so that the soil still gets soaked to a depth of a few inches.

Download a PDF version of our watering instructions.

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July: Butterfly Weed

Butterfly weed has a PR problem, because if all you hear is its name, the weed part is a bit of a turnoff. But it‘s a gorgeous addition to any perennial garden, and pollinators absolutely love it. It’s a tough plant too, which makes it a favorite for rain gardens, bioswales, and low-maintenance, natural style perennial borders.

Photo by Maria Gulley

Photo by Maria Gulley

milkweed-112338_1280.jpg

Brilliant orange flowers in huge clusters up to nine inches across bloom from the center out in July. The stems below the flowers can be a bit bare and thin, so it’s a good middle-layer plant rather than something you plant right at the edge of a bed. You may know butterfly weed best as the monarch butterfly plant - plants in this genus are the only food source for monarch caterpillars. With fewer and fewer wild places where butterfly weed can grow naturally, bringing these plants into our yards is vital to keeping the gorgeous orange butterflies around.

Common Name: Butterfly Weed, Milkweed

Scientific Name: Asclepias tuberosa

Light: full sun

Size: 18-30” tall, 18-24” wide

Bloom Time and Color: large clusters of bright orange flowers in mid-summer

Notable Varieties: ‘Hello Yellow’ (somewhat compact yellow-flowering variety); Swamp Milkweed, a water-loving, pink-flowering cousin, has similar flowers in a different color and is also landscape-friendly

Soil: tolerates clay soil and dry soil

Other Notes: pollinator-friendly, larval host for monarch butterflies, native to Indiana, deer resistant, interesting fall seed pods

See other plants of the month.



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Proper Tree Pruning: Art & Science

It's time for another tree care lesson! If you need a refresher on why we value trees so much, check out our post on the top 10 benefits of urban trees. Today we'll talk about proper pruning technique and why it's so important. The tree you see above has completely closed off some cuts and is working on others with even, donut-shaped callus growing over the wound. That's what you want to see, but getting that result is harder than you might think.

If you've ever needed to prune a tree branch and you haven't been trained on the best methods, chances are you've done one of two things: cut the branch somewhere in the middle to meet whatever clearance needs you're trying to achieve, or cut the branch off flush with the trunk. Both of these are bad for the tree. Trees can't heal wounds in the way people heal cuts on their skin. The tree has to grow new bark from the areas around the cut to seal off the damage, and some parts of the tree are better at this than others. When you cut a branch in the middle, the bark just below that wound can't wrap around and seal off the cut, so instead the branch just dies back to a spot lower down the branch where it can seal itself off, and you're left with a stub that will die. If you cut the branch flush with the trunk, you're creating a much larger wound that provides a bigger area for insects and disease to invade, and it takes longer for the tree to seal it off. The tree pictured above has been pruned properly, and you can see that new bark has totally covered the cuts over the years. Learn how to get these results below.

So where should you make a cut? There's a sweet spot at the base of a branch just before where it connects to another limb or to the trunk. There is a ridge of bark on the top of the branch and a little bump called the branch collar on the bottom. Your goal is to cut just on the outside of these two structure. See the diagram on the right for clarification (click to see larger). It won't always be easy to spot the branch collar on the bottom, so if you aren't sure make your best guess. The angle of the cut should follow the angle of an imaginary line connecting the bark ridge and branch collar. If you're having trouble finding the branch collar, make the angle match the angle of the bark ridge as it extends into the trunk.

Step 1: cut a notch (red arrow) on the underside of the branch about a third of the way through

Step 1: cut a notch (red arrow) on the underside of the branch about a third of the way through

Step 2: cut the branch all the way through at least 4-6” past the notch (red arrow) you cut in step 1

Step 2: cut the branch all the way through at least 4-6” past the notch (red arrow) you cut in step 1

Step 3: make your final cut just outside the bark ridge (red arrow) at an angle away from the tree

Step 3: make your final cut just outside the bark ridge (red arrow) at an angle away from the tree

If you look at a branch that has broken off in a storm, you will sometimes notice that the weight of the falling branch caused a strip of bark to rip off of the trunk as it fell. This can also happen when a branch breaks as you work on sawing through it, and ripping bark like that leaves a wound that can be difficult for a tree to heal over. If you are removing a branch larger than 1" in diameter, you need to use the three cut technique to avoid tearing the bark. First you make a cut on the bottom of the branch further up than where your ideal cutting zone is. This cut should go about a third of the way into the branch. Next, you cut off the branch on the outside of this pre-cut. If the bark starts to rip, it will stop when it gets to your first cut. Your third cut should be at the base of the branch in the sweet spot we discussed above.

Congratulations! You now know how to prune your trees to keep them happy and healthy for years to come! Please spread your knowledge, and never hesitate to ask a professional for help if you have questions. If you’re more of a visual learner, here’s short video that shows how to cut medium-sized branches and shows where you want the finishing cut for any size of branch. For more details written instructions, you can also check out this Purdue Extension bulletin about pruning trees and shrubs.


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June: Tulip Tree

Tulip tree, also known as tulip poplar is Indiana’s state tree. It’s also an attractive, landscape-friendly shade tree that grows at a decent pace and is native to Indiana. Plus it has cool-looking flowers that are a huge hit with bumblebees! It’s a winner all around, as long as you have the space and sun it needs.

Tulip tree became the Indiana state tree in 1931. It was selected for its stately size and form and because it can be found all over the state in mature forests. Tulip trees can become truly massive with trunks over 4’ across. The record-holder for Indiana has a trunk diameter of 280”, or nearly 7.5’ in diameter, and is over 100’ tall. Native Americans used the large trunks to make dugout canoes, and the wood is sometimes used to build furniture today. While tulip trees don’t have many serious pest or disease problems, when they’re under stress they can become susceptible to aphids and tulip tree scale. If you see sticky residue on leaves or on the ground under the tree, take a look at younger stems for tan lumps or aphids, and contact a tree care professional or landscape company with tree experience for diagnosis and treatment.

Common Name: Tulip Tree or Tulip Poplar

Scientific Name: Liriodendron tulipifera

Light: full sun

Size: 60-90’ tall, 30-50’ wide

Bloom Time and Color: green tulip-shaped flowers with cream and orange markings in early summer

Notable Varieties: ‘Majestic Beauty’ (variegated leaves with chartreuse margins

Soil: tolerates clay soil

Other Notes: good golden-yellow fall color, pyramidal form, native to Indiana

See other plants of the month.


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Top 10 Benefits of Urban Trees

Street trees in Rome Photo by Maria Gulley

Street trees in Rome
Photo by Maria Gulley

Many people enjoy looking at trees, using photos of them as desktop backgrounds, or even occasionally planting one on Arbor Day (or when Keep Indianapolis Beautiful hosts a community tree planting in your neighborhood). While the general opinion is in favor of trees, we are sometimes hesitant to have them in urban or suburban settings near our homes and streets because we're intimidated by the damage they can cause or the effort they can require to maintain. In reality, a properly chosen and placed tree requires little maintenance after establishment, and as long as that maintenance is attended to, the chances of a tree crashing down on your house without warning are low. But over and above that, urban trees are important because they provide tremendous (I could have said "tree-mendous" but I stopped myself) benefits to our environment, communities, health, and even economy. Below are the top 10 benefits of urban trees from as ranked by David Nowak at the U.S. Forest Service and presented by the staff at Keep Indianapolis Beautiful.

1. Oxygen Production
If oxygen is so important, why are we placing this benefit at the bottom of the list? Trees do produce oxygen, but the amount produced by urban trees isn't much compared to the amount produced by the oceans and forests of the world, and that oxygen does a pretty good job of working its way through the atmosphere to areas far from oceans and large forests.

2. Noise Reduction and Screening
Trees can buffer the noise from a busy road or highway or help create a quiet spot in a city. Not only can the trees physically reduce some of the sound, but they also mask unpleasant sounds with their own soothing noises of rustling leaves and birdsong.

Trees along the Cultural Trail in downtown Indy Photo by Maria Gulley

Trees along the Cultural Trail in downtown Indy
Photo by Maria Gulley

3. Wildlife Habitat
Without trees, you can't establish much wildlife. Wildlife provides opportunities for informal education and nurturing curiosity, and it is essential to our urban ecosystem. Native trees are especially valuable, as a single species can host literally hundreds of species of native insects that in turn feed birds and other animals. In a few weeks I'll be writing about the value of native wildlife and biodiversity, so tune in for an exciting discussion.

4. UV Radiation Protection
A tree's shade can reduce UV exposure and delay sunburn. The benefit will vary depending on the density and spread of the canopy, but dense shade can offer up to a 95% reduction in UV radiation.

5. Greenhouse Gas Reduction
Trees use the carbon dioxide in the air to make the sugars they need to live, and this helps offset the carbon dioxide we produce both biologically and through burning fossil fuels. In one year, an acre of trees can consume enough carbon dioxide to match what is emitted by an average car driving 26,000 miles. Our urban forests aren't large enough to totally compensate for the amount of carbon dioxide we produce, but they certainly reduce it.

6. Air Quality Improvement
Producing oxygen and capturing carbon dioxide are types of air quality improvement, but urban trees don't stop there. They can also reduce air pollution as the trees catch particulate matter in the air that might otherwise turn into unhealthy smog.

7. Water Quality Improvement
Whenever we get a heavy rain in Indianapolis, we are at risk for a combined sewer overflow. What this means is that so much rain is running off of our paved surfaces and into our sewer system that raw sewage overflows and gets into our natural waterways (see the diagramon the left). Trees can reduce the number and severity of combined sewer overflows by collecting rain on leaves, bark, and in the soil. Indianapolis is doing great work in using green infrastructure to manage stormwater, and was even featured in a 2013 report from the Natural Resource Defense Council, but there is still a long way to go.

8. Health Benefits
Beyond reducing UV radiation, trees offer some surprising and substantial health benefits. Trees reduce asthma and respiratory disease by reducing air pollution. Being around trees and other plants can have psychological effects similar to antidepressants and ADD medication, and they have been shown to reduce stress. Hospital patients with a view of greenery recover faster, require less pain medication, and have fewer complications than patients without such a view.

9. Aesthetic and Socio-Economic Benefits
We intuitively understand the aesthetic benefits of trees. They're beautiful, and they make the spaces around them more beautiful. The socio-economic benefits of trees are less obvious, but studies show that trees reduce crime rates, increase business sales, and reduce traffic speeds, and we also know that they increase property values and strengthen communities.

Street trees in NYC Photo retrieved from Pixabay

Street trees in NYC
Photo retrieved from Pixabay

10. Cooling and Energy Savings
Not all of these benefits can be measured in dollars and cents, but this one can. Trees reduce heating costs through shade and evapotranspiration (as they pull water from the soil, more evaporates from the leaves and has a cooling effect), or they can provide a windbreak to reduce winter heating if properly placed. Adding greenery to cities can reduce or even eliminate the urban heat island effect. The urban heat island effect explains that urban areas tend to be substantially warmer than suburban or rural areas due to the lack of green space and the abundance of heat reflecting surfaces like glass and asphalt.
 

These 10 are by no means the only benefits of urban trees, and many of these could be broken down into several separate benefits, but this gives a glimpse about just how essential trees are in our communities. If you want some handy pamphlets summarizing some of these benefits, I highly recommend these fact sheets produced in collaboration by the Indiana DNR Community and Urban Forestry program and the Indiana Urban Forest Council. To delve into the tree benefits we can put a price tag on, check out the free i-Tree Design tool to calculate the value added by any tree. We don't need to be afraid of trees; we need to embrace them and the benefits they provide. What are some of the reasons you love trees? Can you think of any benefits I left off the list? Feel free to add to the conversation in the comments.


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To Shear or Not to Shear? How to Prune Shrubs

It's the time of the year where you're probably starting to think about tidying up wayward shrubs and pruning hedges during the spring growth spurt. But before you grab shears or gas-powered hedge trimmers, let's talk about proper pruning practices and how they differ from species to species. Not all shrubs can be pruned the same if you want them to live long and prosper.

Rule #1 is to put away your electric or gas-powered hedge trimmers. Unless you're maintaining a substantial yew hedge or something like that, this tool doesn't have a place in shrub pruning. They can be useful for cutting back ornamental grasses or other sturdy perennials, but when used on shrubs they can tear and tatter twigs ends and leave the shrub vulnerable to pest and disease problems, along with leaving unsightly dead tips on branches.

Yews are one of a handful of shrubs that does well with tight shearing, as seen in this image of our work. Photo by Maria Gulley

Yews are one of a handful of shrubs that does well with tight shearing, as seen in this image of our work.
Photo by Maria Gulley

Even if you're using sharp, clean hand shears, a tight globe or box look is not suitable for every shrub in the landscape. For some species, this kind of pruning can result in poor internal structure that leaves huge holes in the shrub if even a single branch is lost. Pruning shrubs into uniform shapes can also rob them of the beauty of their natural form. We pick shrubs not just to provide a desired flower color or fill a space; when we design we take into account the natural shape and texture of a shrub, and if you shear a shrub that isn’t meant to be sheared, you’ll lose its natural beauty. You can also be giving yourself a headache, as some species will fight back with aggressive shoot growth after shearing. If you've ever tried to shear forsythia, you know what I'm talking about.

However, there are times when you want or need the clean formal shapes that a pair of hedge clippers can bring. The following species tolerate shearing well: arborvitae, yew, boxwood, privet*, barberry*, and burning bush*. When shearing a hedge, keep the top slightly narrower than the base. Hedges that are narrower at the bottom often end up thin and scraggly at the bottom because sunlight can't reach the lower branches.

Diagram of proper shrub pruning to reduce overall size. Click to view larger.

So how do you keep other species of shrubs in check if shearing isn't an option? Selective pruning is the process of removing individual branches to control the size and shape of your shrub or promote without destroying its natural shape. Branches can be cut back where they connect to a larger branch or snipped off just above a lower bud. If it seems like the bush is getting too dense and crowded, limbs can be removed all the way down to the ground. Make sure you look twice and cut once so you don't accidentally remove a limb that will leave a bare spot. This may be unavoidable at first if you're switching from shearing to selective pruning, but with time it will be easier. See the diagram on the left for an illustration of selective pruning.

If this seems like a lot of work, don't worry. Once you ditch the shears and pick up the hand pruners, you'll notice that your shrubs need considerably less taming. You will rarely see long, leggy shoots springing up left and right once you switch your methods and stick to it. Instead you'll just be removing the occasional wayward shoot and periodically reducing the shrub's size. If your shrubs have been sheared for so long that you are left with dense growth on the outer few inches and twiggy, leafless growth on the inside, then you may need to resort to renewal or rejuvenation pruning to bring it back to a healthy habit.

Forsythia especially dislikes shearing.  By Rdsmith4 - Own work, CC BY-SA 2.5

Forsythia especially dislikes shearing.
By Rdsmith4 - Own work, CC BY-SA 2.5

One last consideration in pruning is timing. Pruning should be done when the plant has the most time to recover, such as early spring or early summer (unless you're cutting just a few stems - you can do that any time without doing the plant any real harm). If you prune in the hottest part of the summer when your shrub is already stressed, you can increase the plant's stress and make it more vulnerable to other problems. Pruning in the fall can encourage new growth that won't have enough time to mature before freezing temperatures arrive, especially if you're shearing a hedge. Flowering shrubs need to be pruned at different times of year depending on when they flower. Spring blooming shrubs usually develop next year's flower buds during the summer, so it's vital that you prune immediately after flowering so you don't remove next year's flower buds. Summer blooming shrubs usually bloom on new growth, so they should be pruned after flowering, but before new growth starts in spring. Some shrubs can be pruned at any time, because they bloom on both new and old stems. Below I've listed some common flowering shrubs by optimum pruning time.

Prune in spring immediately after flowering:

  • Deutzia (Deutzia gracilis)

  • Forsythia (Forsythia x intermedia)

  • Rhododendron and Azalea (Rhododendron species)

  • Thunberg Spirea (Spiraea thunbergii) (varieties include 'Ogon')

  • Lilac (Syringa species)

  • Viburnum (Viburnum species)

  • Weigela (Weigela hybrids)

  • Dwarf Fothergilla (Fothergilla x gardenii)

  • Chokeberry (Aronia arbutifolia and melanocarpa)

  • Red Twig Dogwood (Cornus sericea)

  • Oak Leaf Hydrangea (Hydrangea quercifolia)

  • Big Leaf Hydrangea (Hydrangea macrophylla)

Prune before spring growth:

  • Butterfly Bush (Buddleia hybrids and species)

  • Beautyberry (Callicarpa species and hybrids)

  • Smooth Hydrangea (Hydrangea arborescens, varieties include 'Annabelle', 'Incrediball', 'Invincibelle Spirit')

  • Hardy Hydrangea (Hydrangea paniculata, varieties include 'Limelight', 'Pinky Winky', 'Quick Fire')

  • Sumac (Rhus species)

  • Virginia Sweetspire (Itea virginica)

  • Summersweet Clethra (Clethra alnifolia)

  • Bumald Spirea (Spiraea x bumalda, varieties include 'Anthony Waterer')

  • Winterberry (Ilex verticillata)


Prune before or after blooming:

  • Reblooming Hydrangeas (Hydrangea macrophylla, specific varieties such as Endless Summer series)

  • Knock-Out Roses (Rosa Knock-Out hybrids)

  • Japanese Spirea (Spiraea japonica, varieties include 'Little Princess', 'Goldflame', 'Magic Carpet')

Azalea Photo by Maria Gulley

Azalea
Photo by Maria Gulley

Dwarf Fothergilla Photo by Maria Gulley

Dwarf Fothergilla
Photo by Maria Gulley

Smooth Hydrangea Photo by Maria Gulley

Smooth Hydrangea
Photo by Maria Gulley

Knock-Out Rose Photo by Maria Gulley

Knock-Out Rose
Photo by Maria Gulley

I've provided some additional resources on pruning shrubs below. Feel free to direct any other questions you may have to me. Good pruning practices are essential to the long-term health and beauty of your garden, and we’d like to help. Contact us to learn more about what our maintenance team can do for you.

Additional Resources:
Pruning Ornamental Trees and Shrubs (Purdue University Extension)
Shrub Pruning Calendar (Virginia Cooperative Extension)

*Privet, barberry, and burning bush are considered invasive and should be avoided. Privet and barberry are included in Indiana’s newly adopted list of banned invasive plants, and they will not be available for purchase within a few years.


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May: Bluestar

There are a lot of perennials that I think deserve more attention. Bluestar is definitely one of them. This plant has an informal but not messy look, blooms earlier than most perennials, stays put where it’s planted, and has brilliantly golden fall color.

There are a handful of species in the genus Amsonia referred to as bluestar that grow naturally in different regions of the U.S. The two that are easiest to find for sale in the Midwest are Amsonia hubrichtii and Amsonia tabernaemontana, and A. tabernaemontana is also native to our region. They all have in common clusters of pale blue flowers and yellow fall color. The main difference is in foliage texture: A. hubrichtii has an airy, fine texture while A. tabernaemontana has a more substantial presence with wider leaves. They are good for massing in mixed perennials beds, and pollinators love the late spring flowers.

Common Name: Bluestar

Scientific Name: Amsonia species, hybrids, and varieties

Light: full sun

Size: 2-3’ tall and wide

Bloom Time and Color: pale blue flowers in May

Notable Varieties: ‘Blue Ice’ (dwarf variety of A. tabernaemontana), ‘Storm Cloud’ (variety of A. tabernaemontana with smoky purple stems and emerging foliage and deeper blue flowers)

Soil: doesn’t like waterlogged soil, but can take a lot of water if it drains quickly

Other Notes: native to Indiana, deer resistant, pollinator-friendly, good fall color

See other plants of the month.


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