What is the lowest temperature spinach can survive?

Spinach is one of the most cold-hardy vegetables, and established plants can survive temperatures down to about 15 to 20 degrees F, with some protection allowing them to overwinter even in cold climates. Seeds germinate in soil as cold as 40 degrees F, and young plants shrug off frosts that would kill warm-season crops. This extreme cold tolerance is why spinach is planted very early in spring, late in fall, and even overwintered under mulch or row cover for an extra-early spring harvest. Its enemy is heat, not cold.

Can spinach grow in summer?

Generally no. Spinach bolts quickly in summer heat and long days, sending up a flower stalk and turning the leaves bitter, and it germinates poorly in warm soil, so midsummer is the wrong time in most of the US. If you want summer greens, grow heat-tolerant substitutes sold as Malabar spinach or New Zealand spinach, which are unrelated plants that thrive in heat, or choose slow-bolting true spinach varieties, grow them in shade, and harvest young. For most gardeners, spinach is a spring and fall crop with a summer break.

How long does spinach take to grow from seed?

Spinach grows quickly, with baby leaves ready to harvest in about 25 to 30 days and full-size leaves in roughly 40 to 50 days from sowing, depending on the variety and the weather. Cooler conditions slow growth somewhat but produce better-quality leaves. Because it matures fast and bolts as it warms, spinach rewards succession sowing every couple of weeks in spring and fall. Cut-and-come-again harvesting, taking outer leaves and leaving the center to regrow, extends a single sowing and lets you start eating even sooner.

Should I start spinach indoors or direct sow?

Direct sowing is usual and works well because spinach germinates readily in cool soil and does not love being transplanted, having a taproot that can be disturbed. For a fall crop, though, late-summer soil is often too warm for good germination, so some gardeners start seeds indoors in a cool spot or pre-sprout the seed in a damp paper towel in the refrigerator before sowing. In spring, direct sowing as soon as the soil can be worked is the simplest and most reliable approach for this fast, cold-hardy green.

When should I plant spinach for a fall harvest?

Sow fall spinach about 6 to 8 weeks before your first expected fall frost, which for most of the US lands in late summer to early fall. Because spinach is so cold-hardy, it keeps producing well past the first frosts and often improves in flavor as the weather cools. In many zones you can sow again a bit later for an overwintering crop, protecting the small plants under mulch or a row cover so they resume growth and give you an extra-early harvest the following spring. Fall spinach is often the best crop of the year.

When to Plant Spinach: Spring, Fall and Overwintering by Zone

Written & researched by Elena Marsh Gardening & Landscaping Editor

Updated February 2026

Over-the-shoulder view of a person harvesting ripe tomatoes into a basket in a backyard vegetable garden, in soft overcast light

Affiliate Disclosure

Some links on this page are affiliate links. As an Amazon Associate, we earn from qualifying purchases — at no extra cost to you. We do not buy, test, or physically handle the products we cover; our rankings come from aggregated owner reviews, ratings and expert consensus. Commissions never change our verdicts. How we rank · full disclosure.

The short answer: plant spinach in cool weather, when soil is 40 to 65°F. For a spring crop, direct sow 4 to 6 weeks before your last frost, as soon as the ground can be worked. For a fall crop — often the best — sow 6 to 8 weeks before your first fall frost. In mild-winter zones you can also sow in fall to overwinter under mulch for an extra-early spring harvest. Spinach is extremely cold-hardy but bolts fast in summer heat, so avoid midsummer entirely.

Spinach is fast, tough, and packed with nutrition, and it is one of the first things you can plant in spring and one of the last in fall. Its single weakness is heat, which makes it bolt, so all of spinach timing is about keeping it in the cool seasons. We do not test the tools we rank; our picks come from aggregated owner reviews and expert consensus, explained in how we rank.

Why spinach is a cool-season crop

Spinach thrives in cool conditions and struggles in heat, a preference driven by two traits. First, it is remarkably cold-hardy: seeds germinate in soil as cold as 40°F, and established plants survive down to 15 to 20°F, so cold rarely limits it. Second, it bolts readily — long days and warm temperatures above about 75°F trigger it to send up a flower stalk, at which point the leaves turn bitter and the harvest ends. Together these mean spinach belongs firmly in the cool shoulder seasons and, in mild climates, right through winter. Fighting its nature by planting in summer is the most common way to fail with it.

Golden-hour view of a person harvesting ripe tomatoes into a basket in a backyard vegetable garden

Spring planting

Spinach is among the earliest crops you can sow, so get it in as soon as conditions allow:

Direct sow 4 to 6 weeks before your last frost date, as soon as the soil can be worked and has reached about 40°F.
Sow successively every 2 weeks through early spring for a continuous supply, stopping well before summer heat.
Choose fast, bolt-resistant varieties for spring, since the season is a race against warming days.

Because spinach dislikes root disturbance from its taproot, direct sowing is preferred over transplanting in spring.

Fall and overwintering

Fall is often the best spinach season because the plants mature into cooling weather that improves flavor and slows bolting. Sow about 6 to 8 weeks before your first fall frost. Late-summer soil may be too warm for reliable germination, so:

Pre-sprout the seed in a damp paper towel in the refrigerator for a few days before sowing, or start in a cool shaded spot.
Sow in the evening and keep the soil moist to cool the surface for germination.

Because spinach is so hardy, a later fall sowing can be overwintered: protect the small plants under mulch or a row cover, and they resume growth in late winter for an extra-early spring harvest — one of the most rewarding tricks in the cool-season garden.

Wide environmental view of a person harvesting ripe tomatoes into a basket in a backyard vegetable garden, in bright midday sun

Planting windows by USDA zone

USDA zone	Spring sowing	Fall sowing	Overwinter?
3 to 4	Late April to May	Late July to August	With heavy cover
5 to 6	Early April	August to early September	Yes, under cover
7	March	September	Yes
8 to 9	February	September to October	Grows through winter
10	Winter crop	October to November	Grows through winter

In the warmest zones, spinach is essentially a fall-through-spring crop grown right through the mild season, while in cold zones it fills a spring and a fall slot with a summer gap.

Soil, spacing and sowing depth

Spinach wants rich, well-drained soil high in organic matter and nitrogen, with a near-neutral pH of about 6.5 to 7.0 (it dislikes acidic soil). Prepare the bed with compost and a nitrogen-supplying fertilizer for lush leaves. When sowing:

Sow seeds 1/2 in deep and about 2 in apart, in rows 12 to 18 in apart.
Thin seedlings to 4 to 6 in apart once they have a few leaves; crowded spinach makes small plants and bolts sooner.
Keep the soil consistently moist for even germination and steady, tender growth.

Low-angle view of a person harvesting ripe tomatoes into a basket in a backyard vegetable garden, in soft overcast light

Care and preventing bolting

Spinach needs steady moisture and steady nitrogen to grow the tender, mild leaves you want; drought and heat both push it toward bolting. Water regularly, mulch to keep roots cool and moist, and provide light afternoon shade as spring warms. Bolting defenses are the same as with lettuce: choose slow-bolting varieties, keep conditions cool and moist, harvest promptly, and time plantings for the cool seasons. Once a plant sends up a central stalk and the leaves turn bitter, it is finished — pull it. Feed with a nitrogen-rich fertilizer for the best leaf production; see best vegetable garden fertilizer.

Harvesting

Spinach is quick to the table — baby leaves in about 25 to 30 days, full leaves in 40 to 50. Harvest by picking outer leaves as needed and leaving the center to keep producing (cut-and-come-again), or cut the whole plant at the base for a full harvest. Pick in the cool of the morning when leaves are crisp. Once you notice a plant starting to stretch upward toward bolting, harvest everything, because the window from bolting to bitterness is short. Succession sowing keeps a steady supply coming in place of one big flush.

Choosing a variety for the season

Spinach comes in three leaf types plus a range of bolt tolerance, and matching the variety to the season improves results.

Type	Character	Best season
Savoy (crinkled)	Dark, heavily crinkled, cold-hardy	Fall and overwintering
Semi-savoy	Lightly crinkled, easier to clean, versatile	Spring and fall — the all-rounder
Smooth-leaf (flat)	Flat leaves, fast, easy to wash	Spring; good for baby leaf

Beyond leaf shape, the key trait to read on the seed packet is bolt resistance. For spring, when the season warms fast, choose slow-bolting or long-standing varieties such as Space, Corvair, or Tyee, which hold in the ground longer before flowering. For fall and overwintering, cold-hardy savoy types like Bloomsdale and Winter Bloomsdale shrug off frost and reward you with thick, sweet leaves. Matching the variety to the season is a small choice that meaningfully extends your harvest window at both ends.

Season extenders help here too. A row cover or low tunnel protects fall and overwintered spinach through hard freezes, and because spinach is so cold-tolerant to begin with, even minimal protection can keep a bed producing through much of a mild winter or jump-start it weeks early in spring.

Spinach shares its cool-season timing with lettuce and brassicas, slotting into the same spring and fall beds — see when to plant lettuce and when to plant broccoli. Everything else is at the seeds and vegetable growing hub.

When to Plant Spinach