When to Plant Cucumbers: Soil Temperature and Sowing Dates by Frost

Cucumbers grow fast once the weather is warm, so there is little to gain by rushing them. Seeds sown into cold, wet soil tend to rot, and transplants set into cold soil sit still. Here is how to time them.

Step 1: go by soil temperature

University of Minnesota Extension says to sow cucumbers after the last frost date, once the soil is at least 70°F at a 1-inch depth, which is late May in most of Minnesota. University of Maryland Extension notes that beans, cucumbers and melons need soil of at least 60°F to germinate, and that cool, wet soil slows germination and makes seeds more likely to rot. Texas A&M AgriLife Extension says not to plant until all danger of frost has passed and the soil begins to warm. A cheap soil thermometer takes the guesswork out of it.

Step 2: dates by last frost

Our planting calendar gives cucumbers a direct-sow window from about a week before your average last frost to 3 weeks after. The week before is only for beds warmed with black plastic and protected by row covers; otherwise, start at the frost date and check soil temperature.

Regional examples: in central Maryland (last frost around April 15), UMD lists cucumber seeds outdoors from mid-May through mid-July. University of Florida IFAS lists cucumber seeds for March to April (and July to August) in North Florida, January to March (and September) in Central Florida, and September through February in South Florida.

Step 3: seeds or transplants?

UMN says direct seeding is the best way to start cucumbers. If you want a head start, sow indoors no earlier than 4 weeks before your last frost, in peat or paper pots that go straight into the ground, and transplant after the frost date before the plants outgrow their pots. Cucumbers have a taproot that doesn't like to be disturbed.

Step 4: plant again for a longer harvest

Bush beans, cucumbers and squash slow down after 3 to 4 weeks of picking, UMD notes, so one sowing gives a burst rather than a steady supply. Sow a second round 3 to 4 weeks after the first; UMD's central Maryland calendar runs cucumber sowings into mid-July. Our succession planting guide has intervals for other crops too.

Step 5: fall cucumbers in hot-summer areas

Texas A&M lists cucumbers as a fall crop, planted in mid to late summer so they finish before the first frost. Average fall planting dates by Texas gardening region:

Elsewhere, count back from your first fall frost using the days to maturity on your seed packet, and add a couple of weeks because growth slows as days shorten.

Where cucumbers go in the garden

Cucumbers are cucurbits, like squash, pumpkins and melons, and share their pests, including cucumber beetles. See what to plant with cucumbers for beans, peas, lettuce and other listed companions, vertical vegetable gardening for trellis ideas, and when to plant melons for their warm-soil cousin. Zucchini and summer squash follow the same warm-soil schedule; see when to plant zucchini.

Frequently asked questions

When should I plant cucumber seeds outside?

After your last spring frost, once the soil is at least 70°F at 1 inch deep (UMN), usually from the frost date to about 3 weeks after.

Can I plant cucumbers before the last frost?

Not unprotected. Cucumbers cannot survive frost. Black plastic mulch and row covers let you sow a little earlier, but cold soil still slows germination.

Should I start cucumbers indoors?

UMN says direct seeding is best. If you start them indoors, sow no earlier than 4 weeks before your last frost in pots that can be planted whole, and transplant after the frost date.

What soil temperature do cucumbers need?

UMD says at least 60°F for germination, and UMN recommends waiting until the soil is at least 70°F at a 1-inch depth.

Is it too late to plant cucumbers in July?

Often not. UMD lists cucumber sowings into mid-July in central Maryland, and Texas A&M plants fall cucumbers from mid-July to October depending on region. Check your days to maturity against your first fall frost.

How often should I plant cucumbers?

Sow a new round about every 3 to 4 weeks into early summer, since cucumber picking slows after a few weeks.