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Johnson County

Research-based Information You Can Trust — Localized for your needs

Johnson County
11811 S. Sunset Drive
Suite 1500
Olathe, KS 66061

Office Hours:

Monday - Friday,
8:30 a.m. - 5 p.m.

(913) 715-7000
(913) 715-7005 fax

Map to our office

K-State Research and Extension is committed to making its services, activities and programs accessible to all participants. Reasonable accommodations for persons with disabilities may be requested by contacting Johnson County Extension at (913)715-7000. Notify staff of accommodation needs as early as possible.

Kansas State University Agricultural Experiment Station and Cooperative Extension Service

K-State Research and Extension is an equal opportunity provider and employer.

April Garden Calendar

Vegetables and Fruits

  • Start fruit tree spray schedule when growth begins
  • Plant carrots, onions, beets and other salad crops in early April
  • Thin radishes, beets and carrots as needed
  • Harvest asparagus until spear size decreases.
  • Prune fruit trees if not already done
  • Plant new fruit trees
  • Plant asparagus and rhubarb
  • Remove mulch from strawberry bed
  • Prune raspberry and blackberry plantings
  • Do not spray insecticides while fruits flower in order to protect the honeybees
  • Plant beans, corn, vine crops in late April
  • Cultivate to control seedling weed growth
  • Turn the compost pile after a long winter rest
  • Transplant broccoli, cauliflower and cabbage in the garden
  • Fertilize vegetable garden before planting and incorporate


  • Remove winter mulch from perennial garden
  • Cut back last year's growth from perennials
  • Remove seed heads from spring bulbs
  • Do not remove foliage from spring flowering bulbs as growth is needed for next year's flowers
  • Fertilize spring flowering bulbs
  • Add organic matter such as compost before planting new flowers
  • Divide perennials
  • Plant new roses
  • Prune rose bushes
  • Fertilize rose bushes for spring growth
  • Plant annuals from seed and transplants


  • Apply crabgrass control by mid month
  • Mow lawn as needed, bluegrass 2", tall fescue 3"
  • Fertilize cool season lawns with slow release nitrogen fertilizer
  • Do not fertilize zoysia this early in spring, nutrients go to weeds not dormant grass
  • Spot treat broadleaf weeds such as dandelions, henbit, and chickweed
  • Check mower and make needed repairs before season begins
  • Sharpen mower blade
  • No need to catch grass clippings if mowing frequently
  • Do not water unless extremely dry, early irrigation sets turf up as high water user in summer

Trees and Shrubs

  • Prune spring flowering shrubs such forsythia and lilac after flowering
  • Prune trees as needed, and repair winter storm damage
  • Topping is not pruning, never top a tree
  • Plant new trees and shrubs
  • Remove grass from base of young trees and shrubs to prevent lawn mower and line trimmer damage
  • Apply mulch layer around plants
  • Keep new trees and shrubs watered
  • Fertilize young trees to promote growth

House Plants

  • Remove winter dust from leaves by gently rinsing with room temperature water 
  • Repot as needed, increase pot size by 1"
  • Leach excess fertilizers from soil with water
  • Begin summer fertilization of plants
  • Do not move plants outside until night temperatures remain over 60 degrees
  • Propagate house plants by cuttings or divisions
  • Fertilize amaryllis and keep in bright light to encourage new leaves

Return to Garden Calendar

K-State Research and Extension Johnson County Master Gardener logo

Have questions? The Garden Hotline is staffed by trained EMG volunteers and Extension staff who will assist you with questions.

Phone: (913) 715-7050

Email: garden.help@jocogov.org