The Gardener's Calendar


March - May

  • Apply an all-purpose slow-release fertilizer to perennials and shrubs in late March to mid-April
  • Remove any additional leaves that fell through the winter
  • If deer eat your crocuses and other bulbs, start using your deer repellant of choice as flowers emerge. Continue to apply as needed to plants deer love
  • Add a soil acidifier around acid-loving plants such as hollies, azaleas, and rhododendrons in March
  • Cut back any perennials left over from the fall
  • Start irrigation system back up
  • Prune any dead branches out of roses, hydrangeas, and other sensitive shrubs
  • Apply preventative fungicides to any plants that suffer from serious spring fungal infections before rainy weather sets in
  • Begin training climbing vines as the spring growth spurt hits
  • Lawn application Round 1 is applied in March
  • Spring annuals and container arrangements can go in between late March and late April depending on the desired plants
  • Put down pre-emergent herbicide in planting beds in late March to mid-April
  • Put down a fresh layer of mulch – be sure to keep it from touching tree trunks or burying shrubs bases
  • Redefine bed edges
  • If evergreen trees need to be fertilized, early March is a good time
  • Overseed thin lawns and spot-seed bare spots in March
  • Divide perennials as needed when they have emerged enough to find them easily but before the leaves have opened up much – this will be about 3-4” high for most plants
  • Begin pulling or spraying weeds as they emerge (be sure to exercise caution and read all labels when using herbicides)
  • Lawns are ready to be mowed in mid to late April
  • Lawn application Round 2 is applied in late April to early May
  • Put peony supports up while the new growth is still short – as the leaves expand they will hide the hoops
  • Replace plants that didn’t survive the winter
  • Start using slug control around hostas in May
  • Pinch back leggy perennials that bloom in mid-summer by the end of May
  • Deadhead spring-blooming perennials as needed
  • Summer annuals can be planted in mid-May after the last freeze date
  • Prune spring-blooming shrubs such as forsythia and vernal witch hazel as soon as they’re done blooming


June - August

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  • Significant tree pruning can be done in early June after the rainy season and before the weather gets hot
  • Plant summer annuals in the ground and containers in June if you didn’t in May
  • Pull and spray weeds through the summer (be sure to read all labels for herbicides)
  • Deadhead perennials and roses to extend bloom season
  • Stake leaning perennials
  • Cultivate mulch for a fresh look
  • During long dry spells, water drought-sensitive plants
  • Cut back asters and other tall, fall-blooming plants to keep them from getting overgrown in the fall
  • Trim unruly perennials like catmint and Russian sage to keep them from covering paths and other plants
  • Lawn application Round 3 is applied between mid-June and mid-July
  • Keep fountains filled and containers watered in the hot sun
  • Prune shrubs as they get unruly


September - November

  • Seed new lawns between mid-September and mid-October
  • Pull and spray weeds through the fall (be sure to read all labels for herbicides)
  • Aerate and overseed lawns
  • Lawn application Round 4 is applied in September
  • Starting in mid-September fall annuals are available for containers and in-ground planting
  • Prune shrubs as they get unruly (if you prune spring-blooming shrubs in the fall, you will remove some or all of the next year’s flowers)
  • Cultivate mulch for a fresh look
  • Continue to deadhead perennials, roses, and hydrangeas
  • Cut back perennials as they drop their leaves and turn brown
  • Leave grasses and other perennials with winter interest – little bluestem and blue false indigo can add a lot to the cold months
  • Do any lawn over-seeding or seed new lawns by the end of September
  • Divide and transplant perennials in mid-September and October
  • Plant bulbs in October and November before the ground freezes
  • Lawn application Round 5 is applied in October
  • Blow out irrigation systems in October and November
  • Sensitive heirloom rose varieties should be tied up with leaves as insulation
  • Disconnect and drain hoses before the first freeze
  • Leaf removals start in October and extend into December
  • Deep root tree fertilization happens in November


December - February

  • Put up holiday lights, decorations, and container arrangements
  • Put reflective markers at driveway edges to help snow plows stay on track
  • Watch out for winter damage to trees and shrubs – broken tree branches should be properly pruned before spring
  • Perform any dormant pruning on trees and shrubs
  • Cover or bring in outdoor furniture
  • Clean and repair outdoor furniture
  • Review garden plans and dream up ideas for next year