When to Plant Cucumbers in Missouri
Published: April 21, 2026
Missouri gardeners in Zone 6b have a 33-week growing season for cucumber (March 22 to November 10). The moderate climate supports a full warm-season crop plus an often-productive fall crop. This guide gives exact dates for Missouri based on your local frost calendar.
Cucumber Planting Dates for Missouri
| Start seeds indoors | March 1–8 |
| Last frost (average) | March 22 |
| Transplant outdoors | March 29–April 8 |
| Direct sow outdoors | March 29–April 8 |
| Expect first harvest | May 18 – June 7 |
| Fall crop start | September 1–11 |
| Fall harvest | October 21 |
| First fall frost (average) | November 10 |
Dates above assume Zone 6b, the most common zone in Missouri. Gardeners in cooler St. Louis (Zone 6b) plant 1–2 weeks later; warmer Kansas City (Zone 6a) can plant 1–2 weeks earlier.
Growing Cucumbers in Missouri's Climate
Missouri's moderate Zone 6b climate is well-suited to cucumber with minimal special accommodation. The standard transplant calendar works as written, and harvest windows line up with what seed packets recommend without adjustment.
Succession planting extends your cucumber harvest significantly in Missouri. A second planting 3 to 4 weeks after the first gives you a backup in case of pest pressure and extends the total harvest window into early fall.
Common cucumber pests to watch for in Missouri include Cucumber Beetle and Squash Vine Borer. The first line of defense is companion planting: Radish and Nasturtium planted nearby discourage several of these pests by confusing host-plant identification or repelling adults before they can lay eggs. Weekly garden walks in the early morning catch problems when they're still manageable.
Cucumber Garden Calendar for Missouri
| Month | Task | Notes |
|---|---|---|
| January | — | Dormant season |
| February | — | Dormant season |
| March | Transplant outdoors | Soil temp must be 60°F+; nighttime lows above 50°F |
| April | — | Dormant season |
| May | First harvest window opens | Cucumber begins producing 50–70 days after transplant |
| June | Peak growth; water 1 inch/week | Monitor for pests daily; stake or support as needed |
| July ← | Start fall crop seeds | Fall transplants go in 10 weeks before first frost |
| August | — | Dormant season |
| September | Fall crop planting | Transplant or direct sow for fall harvest before frost |
| October | — | Dormant season |
| November | First frost approaches | Harvest remaining cucumber; cover plants on frost nights |
| December | — | Dormant season |
Cucumber Growing Tips for Missouri Gardeners
- •Direct sow after last frost rather than transplanting — cucumbers establish faster from seed in warm soil.
- •Trellis vertically to save space and reduce powdery mildew from soil splash.
- •Missouri's moderate climate supports succession planting — sow new transplants or seeds every 3 weeks during spring to extend the harvest window into fall.
- •Harvest every 2–3 days — cucumbers left on the vine signal the plant to stop producing new fruit.
Companion Planting for Cucumbers in Missouri
In Missouri's moderate climate, planting cucumber with Radish and Nasturtium helps deter pests and improve soil. Avoid planting near Aromatic Herbs and Potato, which inhibit cucumber growth through root chemistry or shared pest pressure. See the full cucumber companion planting guide for the complete list.
Cucumbers Planting Dates by City in Missouri
Top cities in Missouri — select for city-level frost dates and planting calendars.
Frequently Asked Questions
When should I plant cucumber in Missouri?
In Missouri (Zone 6b), start cucumber seeds indoors around March 1–8 and transplant outdoors around March 29–April 8 — 1 weeks after the state's average last frost of March 22.
What is the last frost date in Missouri?
Missouri's average last frost date is March 22 in the state's most common Zone 6b. Frost dates vary by city — higher elevations and northern counties run 1 to 3 weeks later than the state average. See the city list below for city-level frost dates.
Can I grow cucumber year-round in Missouri?
Not year-round — Missouri's cold season stops cucumber production. The cucumber season runs March 22 to November 10, roughly 33 weeks. A fall crop extends harvest into late autumn.
What cucumber varieties grow best in Missouri?
For Missouri's Zone 6b, Marketmore, Straight Eight, and Pickler each have specific uses; pick based on fresh-eat vs pickling preference.
When do I start cucumber seeds indoors in Missouri?
Start cucumber seeds indoors in Missouri around March 1–8, which is 3 weeks before the state's average last frost of March 22. Use grow lights and keep soil temperatures at 70–75°F for fastest germination.