Vegetable Growing Guide
Cool and warm season vegetables — with variety picks, KC-specific timing, and planting windows. Last frost April 15 · First frost October 15 · 183-day season.
Zone 6a Seasonal Guide
KC sits in USDA Zone 6a with a last frost around April 15 and a first frost around October 15 — a 183-day growing season. Cool-season crops thrive in the March–May and August–October windows; warm-season crops need the frost-free May 15–October 15 window. This guide tells you what to do in every window of the year.
Start indoors now: Celery (January), leeks and onion seed (Jan–Feb), tomatoes and peppers (Feb 1–15), broccoli, cabbage, and cauliflower (Feb 20–Mar 15).
Not yet: Nothing goes outdoors. Soil is frozen or too cold for germination.
Garden tasks: Order seeds before popular varieties sell out. Map crop rotation on paper — nightshades, brassicas, cucurbits, and legumes should each move to a new bed each year. Prune fruit trees while dormant. Clean and sterilize tools.
Direct sow as soon as soil is workable: Arugula, spinach, lettuce, radishes, turnips, beets, and peas germinate at 35–45°F. No waiting for warm soil.
Transplant outdoors (frost-tolerant): Broccoli, cabbage, kale, lettuce, and onion starts can go out after hardening off — they tolerate light frost.
Not yet: Tomatoes, peppers, cucumbers, squash, and beans all wait until after last frost (Apr 15) and until soil warms to 60°F+.
Last frost passes April 15 — but soil is still cold. Wait until soil hits 60°F+ before planting warm-season crops. A thermometer 2" deep is the real signal.
Transplant after soil warms: Tomatoes and peppers go out May 10–20. Cucumbers, squash, zucchini, and beans follow after May 15 when nights stay above 50°F consistently.
Still producing: Spring cool crops (peas, lettuce, spinach, broccoli) are in full swing. Harvest hard — the window closes fast when June heat arrives.
Harvest daily: Cucumbers, zucchini, green beans, and tomatoes must be harvested constantly. Missing even one day turns perfect produce into over-mature seed bombs.
Plant for fall: Start broccoli, cauliflower, and cabbage seeds indoors July 1–15 for fall transplants. Direct sow beets, carrots, and kale outdoors Aug 1–15.
Water deep: KC summers are hot and dry. Aim for 1–2" of water per week, applied deeply at the root zone. Mulch everything with 3–4" of wood chips.
Direct sow fall cool crops: Arugula, spinach, lettuce, radishes, and turnips. Count back from Oct 15 — most cool crops need 25–50 days. Last sowing dates: lettuce and arugula through Sep 30; radishes through Oct 1.
Transplant fall brassicas: Broccoli, cabbage, and kale transplants go out Aug 15–Sep 1. Fall brassica crops in KC are almost always better than spring — no bolting pressure.
Plant garlic Oct 1–Nov 15: KC's most reliable, productive, and lowest-maintenance crop. Plant cloves 2" deep, 6" apart, cover with 4" of straw mulch.
Still harvesting: Kale, leeks, Brussels sprouts, and root vegetables (carrots, parsnips) actually improve after frost — cold converts starches to sugars. Mulch heavily and keep harvesting through November.
Storage crops: Cure winter squash and sweet potatoes at 80–85°F for 2 weeks. Braid and cure onions and garlic. Dig potatoes before the ground freezes hard.
Extend the season: Cold frames add 6–8 weeks — grow spinach and arugula into December. A single cold frame is one of the best investments in a KC vegetable garden.