Plant of the Month

October: Summersweet

Trees are usually our first thought when we think of fall color, but some shrubs are real stunner as well. Summersweet, know in some places as Sweet Pepperbush, is an excellent shrub for the landscape with great fall color. It also has lovely, fragrant flower spikes and thick, shiny leaves in the summer, so it’s a winner all year long.

Summersweet is native to the coastal regions of the southeastern U.S. where it grows naturally on semi-shaded riverbanks in forests and on the edge of forests. If left to its own devices, it will spread by suckers to form a colony, and in the wild this helps to stabilize streambanks. In the landscape, suckers can be removed without much effort to keep them in place. There are many varieties of summersweet available in different sizes. The wild species is pretty large, growing up to eight feet tall, but one of the most popular varieties, Hummingbird, tops out at four feet tall in ideal conditions, but will stay closer to 2-3’ tall in most clay Midwest soils. It’s a great pick for rain gardens since it can tolerate wet conditions. The sweet and spicy smelling flowers are popular with both people and pollinators.

Common Name: Summersweet or Sweet Pepperbush

Scientific Name: Clethra alnifolia

Light: full sun to partial shade

Size: 2-8’ tall and 2-6’ wide (varies widely depending on variety)

Bloom Time and Color: white or pink upright flower spikes in late summer

Notable Varieties: ‘Sixteen Candles’ (narrower, semi-dwarf variety 4-5’ tall and 2-3’ wide with white flowers), ‘Ruby Spice’ (pink-flowering variety slightly more compact than straight species), ‘Hummingbird’ (dwarf variety 2-4’ tall and 3-5’ wide with white flowers)

Soil: can grow in sand or clay, tolerates soggy conditions

Other Notes: good fall color, attracts pollinators, fragrant flowers, spreads by suckers if permitted

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September: Anemone

September: Anemone

We all want some late season blooms to keep our landscapes vibrant as the temperatures cool off, and anemone is an excellent candidate. Also known as windflower, these perennials send up long stalks with airy white or pink flower in September and October, and they sway gracefully in a breeze for an ethereal feel.

August: Wild Ginger

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.

July: Butterfly Weed

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.

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

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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

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April: Flowering Dogwood

April: Flowering Dogwood

If you ask someone what their favorite tree is, there’s good chance that they will name a spring-flowering beauty. And of those spring bloomers, flowering dogwood is a classic crowd-pleaser. With its snowy white or soft pink blossoms, flowering dogwood stands as a sign that spring has fully arrived at last.

March: Fragrant Sumac

March: Fragrant Sumac

Fragrant sumac is an adaptable, low-maintenance shrub perfect for even the toughest situations. It thrives even planted in clay, surrounded by asphalt, and battered and dried by full sun. It spreads to form colonies that retain slopes and block out weeds. As long as you don’t plant it in a bog, it will hold the line and even bring some spring and fall surprises just about anywhere.

February: Sycamore

February: Sycamore

Sycamore trees are among the most distinctive trees in the American landscape. Whether you know the name or not, you have no doubt noticed beautifully mottled gray and tan and white bark on a giant of a tree in a park or a forest or driving along the highway. For me, it was one of the first trees I learned to identify growing up as a budding plant nerd.

January: Serbian Spruce

January: Serbian Spruce

For a dense evergreen tree in a classic Christmas tree shape, Serbian spruce is the best fit for central Indiana. The needles have thin white stripes that give the tree a faint white-ish cast from a distance for a softer look. They work well as focal points, or in groups to form a living barrier.