monthly gardening calendar

Stay on top of your gardening tasks in northern Illinois with our monthly gardening calendar.

March

  • Start seeds indoors for the season. Sowing dates to be determined by species.
  • Prepare garden beds for planting by removing winter mulch and adding compost if warm enough.
  • Prune fruit trees and berry bushes before new growth appears.
  • Test soil and adjust pH levels as needed if you think your soil might need to be amended.
  • Cut back dead or damaged branches from shrubs and trees.
  • Check and clean garden tools and equipment.
  • Water evergreens (especially the young plants) if the month has been dry.
Gardening calendar - March
Gardening calendar - April

April

  • Start hardening off seedlings started indoors before planting them outside.
  • Divide and transplant perennials.
  • Plant cool-season crops like peas, radishes, and carrots directly into the ground when the soil and air temperature are at least 40 degrees.
  • Apply a layer of mulch to garden beds. We prefer to use our finer mulches at this point rather than thick wood chips.
  • Plant herbs like basil, parsley, and cilantro.
  • Monitor for pests and diseases and treat as needed. Apply pre-emergent weed killer to beds. You can preventatively spray fruit trees when the temp exceeds 40 degrees.
  • Fertilize trees and shrubs with a slow-release fertilizer, or a general fertilizer like 10-10-10.

May

  • Plant warm-season crops like tomatoes, peppers, and cucumbers after the last frost date.
  • Start planting annuals like petunias, marigolds, and impatiens.
  • Thin seedlings to provide enough space for each plant to grow.
  • Monitor for signs of drought and water deeply as needed.
  • Stake or trellis tall plants to support their growth.
  • Apply a second round of fertilizer to vegetable plants.
  • Harvest cool-season crops like lettuce, spinach, and kale.
  • Deadhead flowers to encourage more blooms.
  • Take photos of your garden to track its progress over time.
Gardening calendar - May
Gardening calendar - June

June

  • Harvest early-season vegetables like peas, lettuce, and spinach.
  • Plant heat-tolerant annuals like zinnias and sunflowers.
  • Prune spring-flowering shrubs after they finish blooming.
  • Water deeply and regularly, especially in the heat of summer.
  • Monitor for pests like aphids and spider mites and treat as needed.
  • Apply a layer of compost or organic fertilizer to garden beds.
  • Mulch around plants to retain moisture and suppress weeds.
  • Take notes on what is working well and what could be improved in your garden.
  • Harvest herbs like mint, thyme, and oregano for fresh use or drying.

July

  • Harvest tomatoes, peppers, cucumbers, and other warm-season vegetables.
  • Deadhead perennial flowers like daylilies and coneflowers.
  • Keep up with watering, especially during dry spells.
  • Monitor for pests and diseases and treat as needed.
  • Apply a third round of fertilizer to vegetable plants.
  • Start planning for fall crops like broccoli and kale.
  • Take a soil test to determine any necessary adjustments before planting fall crops.
  • Propagate plants like basil or coleus by taking cuttings and rooting them in water.
Gardening calendar - July
Gardening calendar - August

August

  • Harvest Continue harvesting vegetables like tomatoes, peppers, and cucumbers.
  • Plant fall crops like broccoli, cauliflower, and cabbage.
  • Cut back overgrown perennials to encourage new growth.
  • Water deeply and regularly, especially during hot spells.
  • Deadhead annual flowers to encourage more blooms.
  • Mulch around plants to retain moisture.
  • Divide and transplant perennials that have finished blooming.
  • Plant fall-blooming bulbs like crocus and daffodils.
  • Harvest herbs like basil and mint before they begin to flower.

September

  • Harvest late-season vegetables like squash, pumpkins, and carrots.
  • Plant cool-season vegetables like spinach, lettuce, and kale.
  • Cut back spent annuals and perennials.
  • Divide and transplant perennials like hostas, daylilies amd iris.
  • Take steps to protect tender plants from frost, like covering them with a blanket or cloth.
  • Plant spring-blooming bulbs like tulips and daffodils.
  • Prune shrubs that have finished blooming.
Gardening calendar - September
Gardening calendar - October

October

  • Harvest remaining vegetables and fruits before the first frost.
  • Clean up the garden beds by removing dead plants and debris.
  • Plant spring-blooming bulbs like crocus and hyacinths.
  • Store garden tools and equipment properly for winter.
  • Prepare garden beds for winter by adding a layer of mulch.
  • Divide and transplant perennials before the ground freezes.
  • Bring in tender plants like tropicals or houseplants before the first frost.
  • Enjoy the fall colors in the garden and take photos to remember the season.