1. K-State home
  2. »Research and Extension
  3. »Johnson County
  4. »Lawn and Garden
  5. »Gardening Calendar

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.

Gardening Calendar

Great gardens don't just happen. They take careful planning. This garden calendar should help with your planning process.

Average Frost Free Dates for Johnson County, Kansas


Percentage Chance of Frost
(32 degrees F)

50/50 ChanceApril 15 (Average last frost date)
40%April 18
30%April 21
20%April 25
10%April 30
5%May 4
1%May 13
  • Earliest date of last frost was March 15, 1910.
  • Latest date of last frost was May 14, 1914.


Percentage Chance of Frost
(32 degrees F)
50/50 ChanceOctober 23 (Average first frost date)
40%October 20
30%October 17
20%October 13
10%October 9
5%October 5
1%September 29
  • Earliest date of first frost was September 24, 1942.
  • Latest date of first frost was November 11, 1946.
K-State Research and Extension Johnson County Master Gardener logo

Have questions? The Hotline is staffed by trained EMG volunteers and Extension staff who will assist you with questions.
Phone: (913) 715-7050
Diagnosing Plant Problems

The Horticulture staff and EMGs are available to assist you in identifying your lawn and garden problems. Click on the following link to learn more.