When to Plant Spinach in Spring: Dates by Frost and How to Avoid Bolting

Spinach is one of the hardiest vegetables in the garden. Young plants tolerate hard frosts, and UMD describes it as able to withstand heavy frosts in spring and fall. The risk with spring spinach is planting too late, not too early. Penn State notes many home gardeners give up on spinach because they start it too late in spring, so it runs into long days and bolts before it has made many leaves. This guide covers spring sowing; for fall crops, see when to plant spinach and kale in fall.

Spring dates by last frost

The first column uses Penn State's 4-to-8-week window; Texas A&M's vegetable table is wider, 1 to 8 weeks before the frost-free date. Our planting calendar uses a narrower window of 4 to 3 weeks before the frost, so it sits at the late end of Penn State's range. The last column shows example repeat sowings, a week apart, from the middle of the window.

Very early starts are possible. Illinois Extension says that if the bed was prepared the previous fall, seed can be broadcast over frozen ground or snow in late winter, and it will germinate as the soil thaws. Penn State suggests a raised bed, which warms quickly, and a clear cover over the bed for the first few weeks of an early spring sowing.

Soil temperature and cold

Why spring spinach bolts

Spinach responds to lengthening days by bolting, sending up a flower stalk, after which the leaves turn bitter. UMN says hot weather makes plants respond faster to the day-length signal and drought speeds it up, so in Minnesota spinach tends to bolt in June even when it is cool. Penn State says that once temperatures reach about 80°F spinach will bolt, so a spring planting's productive life usually ends by late May in Pennsylvania. Ways to get more from spring spinach:

• Sow early and in small batches every one to two weeks, stopping when outdoor temperatures reach 80°F (UMN).
• Choose slow-bolting varieties. Illinois says "long-standing" or slow-to-bolt varieties are best for spring.
• Keep the soil moist; Penn State says spinach bolts if the soil dries out, and failing to thin seedlings can also cause early bolting.
• Shade late sowings: Penn State suggests shade cloth as days lengthen and temperatures warm to 70°F.

Texas, Florida and mild-winter areas

In warm regions spinach is a fall and winter crop more than a spring one. Texas A&M's Easy Gardening guide says to plant spinach as early as the soil can be worked in spring, or in August or later for fall; its fall guide lists spinach by Aug 15 (Region I) through Dec 15 (Region V). University of Florida IFAS lists spinach from September through March in North Florida, September through February in Central Florida and October through February in South Florida. UMD notes that in mild areas, spinach sown in late fall can overwinter and grow again in spring, and Illinois says seedlings often survive winter in southern locations on well-drained soil.

Where spinach goes in the garden

Spinach shares a cool, early bed with peas, lettuce and radishes, and it can tuck into partial shade: UMD says it tolerates 4 to 6 hours of direct light a day. See what to plant with spinach for companions, when to plant lettuce and when to plant peas for crops sown at about the same time.

Frequently asked questions

When should I plant spinach in spring?

About 4 to 8 weeks before your average last frost (Penn State), or as soon as the soil can be worked (UMN, Illinois). Texas A&M allows 1 to 8 weeks before the frost-free date.

Can spinach seedlings handle frost?

Yes. Penn State says young seedlings tolerate 15 to 20°F, and UMD describes spinach as able to withstand heavy frosts in spring and fall.

What soil temperature does spinach need to germinate?

Best between 45°F and 68°F (Penn State). UMD says to sow after the soil reaches 45°F.

Is it too late to plant spinach in May?

In most areas, yes for a spring crop. Long days and temperatures near 80°F make spinach bolt (Penn State, UMN). Wait and plant a fall crop instead, or grow a heat-tolerant green.

How often should I sow spinach?

Every one to two weeks until outdoor temperatures reach 80°F (UMN). Small batches give a steady supply before bolting.

Why does my spring spinach bolt so fast?

Spinach bolts in response to lengthening days, faster in heat and drought (UMN). Sow earlier, keep the soil moist, thin seedlings and choose slow-bolting varieties.