Early spring is the gardener's best-kept secret. While most people wait for the last frost to pass before touching a trowel, seasoned growers know that late March is precisely the moment to get certain vegetables in the ground — or at least started indoors. The cool, damp soil of this time of year, with temperatures hovering between 5°C and 12°C (40°F–55°F), is exactly what a handful of hardy vegetables need to establish strong root systems before the heat of summer arrives.
These five cool-weather vegetables thrive in the very conditions that would stall warm-season crops. Planting them now means you'll be harvesting weeks ahead of schedule — sometimes as early as May — and freeing up your beds for tomatoes, peppers, and squash later in the season. Grab your seed trays, your dibber, and a bag of good-quality seed compost: the season starts today.
| Preparation time | 30 min |
| Planting time | 1–2 hours per vegetable |
| Time to first harvest | 4–10 weeks depending on the crop |
| Estimated season | Spring (late March through May) |
| Difficulty | Beginner to Intermediate |
| Recommended season | Late winter / Early spring |
What You'll Need
- Seed trays or modular plug trays (for indoor starts)
- Good-quality seed compost or multi-purpose compost
- A dibber or pencil for making planting holes
- Watering can with a fine rose head
- Horticultural fleece or a cold frame (for outdoor direct sowing)
- Labels and a waterproof marker
- A trowel and hand fork
- Garden gloves
The 5 Cool-Weather Vegetables to Plant Right Now
1. Peas
Peas are one of the earliest crops you can direct sow outdoors, and late March is an ideal window in most temperate regions. They germinate in soil as cold as 7°C (45°F) and actually prefer it: warm soil encourages rotting before the seed can sprout. Choose a sheltered, sunny spot and work the soil to a fine tilth — the texture should feel crumbly between your fingers, not compacted or cloddy.
Sow seeds roughly 5 cm (2 inches) deep and 7–10 cm (3–4 inches) apart in a double row, leaving about 60 cm (24 inches) between double rows to allow for support structures. Push the seeds in with your thumb or a dibber, firm the soil gently over each one, and water in well with a fine rose to avoid washing seeds sideways. Install bamboo canes or pea netting immediately — peas grow fast and will need something to grip within two to three weeks. A layer of horticultural fleece over the row for the first fortnight will protect against late frost and keep hungry pigeons at bay.
2. Spinach
Spinach is one of the most cold-tolerant leafy crops available, capable of germinating in temperatures as low as 4°C (39°F). Sowing now outdoors, under fleece, will give you a cut-and-come-again harvest in as little as four to five weeks. The key with spinach is to sow little and often: a short row every two weeks prevents glut and extends your picking window well into May before the plants begin to bolt — the term for when a plant prematurely sends up a flowering stem, turning the leaves bitter.
Prepare a well-drained bed and make shallow drills about 1 cm (½ inch) deep and 30 cm (12 inches) apart. Sow seeds thinly along the drill, cover lightly with compost, and firm down with the back of a rake. Thin seedlings to about 7 cm (3 inches) apart once they reach 5 cm (2 inches) tall. Keep the soil consistently moist but never waterlogged — spinach dislikes sitting in cold wet conditions for extended periods.
3. Lettuce
Loose-leaf and butterhead lettuces are natural companions for a March sowing programme. They tolerate light frost, establish quickly in cool soil, and can be started either in trays indoors or direct-sown under a cloche. For the fastest results, sow in modular plug trays indoors at a temperature of around 15°C (60°F), then transplant outside under fleece once seedlings have developed four true leaves — usually within three weeks.
Choose varieties bred for cool conditions: 'All Year Round', 'Lollo Rosso', or 'Little Gem' are all reliable performers in early spring. Space transplants 25–30 cm (10–12 inches) apart in each direction to allow airflow, which reduces the risk of grey mould (Botrytis cinerea), a fungal disease that thrives in cold, damp, overcrowded conditions. Begin harvesting outer leaves as soon as the plant reaches a usable size — this encourages continued production rather than triggering bolting.
4. Broad Beans
If you missed an autumn sowing, late March is your last realistic chance to get broad beans in the ground and still achieve a worthwhile harvest before summer heat sets in. Unlike their runner and French counterparts, broad beans are hardy annuals — plants that complete their lifecycle in one growing season but are built to withstand cold — and will push through even a light frost without flinching.
Sow seeds 5 cm (2 inches) deep and 20–25 cm (8–10 inches) apart in double rows, with at least 45 cm (18 inches) between each double row. The soil should be firm but not compacted: broad beans appreciate a nutrient-rich, well-drained bed with a near-neutral pH of around 6.5 to 7. Once plants reach 15 cm (6 inches), pinch out the very tip of each stem — this is called stopping, and it improves airflow, reduces the risk of blackfly infestation, and directs the plant's energy towards pod development rather than vegetative growth.
5. Kale
Kale is arguably the most resilient vegetable in this list. It tolerates frost down to around -10°C (14°F), grows vigorously in cool, moist conditions, and produces harvest-ready leaves across an extraordinarily long season. Starting plants from seed now — indoors in trays or under a cold frame — gives you sturdy transplants ready for their final beds by mid-May, setting up a harvest window that can run from summer right through to the following February.
Sow kale seeds 1 cm (½ inch) deep in plug trays filled with moist seed compost. Germination occurs within five to seven days at around 18°C (65°F). Prick out seedlings into individual 7 cm (3-inch) pots once the first true leaf appears, and grow on in a cool but frost-free environment — a cold frame or unheated greenhouse works perfectly. Harden off plants over seven to ten days before transplanting to their final position: place them outside in a sheltered spot during the day, bring them back under cover at night, gradually increasing their outdoor exposure. 'Nero di Toscana' (also known as Cavolo Nero), 'Red Russian', and 'Redbor' are all excellent varieties for a spring start.
The Professional's Tip
The single most common mistake in early spring sowing is impatience with soil temperature. Even if air temperatures feel mild in late March, soil can lag several weeks behind — and cold, waterlogged ground will cause seeds to rot before germination. Use a basic soil thermometer (widely available for under $10 / £8) and check the temperature at a depth of 5 cm (2 inches) before you sow anything directly outdoors. Aim for at least 7°C (45°F) for peas and broad beans, and 10°C (50°F) for lettuce and spinach. If your soil isn't there yet, lay black polythene or a sheet of fleece over the bed for a week to trap solar heat — you'll be surprised how quickly it warms the top layer.
Care and Ongoing Maintenance
All five of these crops benefit from consistent moisture without waterlogging. Check soil moisture by pushing a finger 3–4 cm (1–1.5 inches) into the ground: if it feels dry at that depth, water thoroughly at the base of plants rather than overhead, which reduces the risk of fungal disease in cool weather. A 5 cm (2-inch) layer of garden compost or well-rotted manure applied as a mulch around established seedlings helps retain moisture, suppress weeds, and steadily release nutrients.
Watch for slugs and snails, which are particularly active in cool, damp March and April conditions. Copper tape around raised beds, crushed eggshells, or organic iron phosphate pellets are effective low-impact deterrents. Remove any yellowing or damaged outer leaves promptly — they act as entry points for disease and attract pests.
Planning Ahead: Succession and Bed Management
One of the practical advantages of cool-weather crops is that most will clear the ground before mid-summer, freeing up space for warm-season plantings. Peas and broad beans are typically finished by July; spinach and lettuce often run their course by June. Plan your bed rotation now so that each cleared row becomes a prepared site for tomatoes, courgettes, or climbing French beans — a simple sketch on paper, noting which crops go where and when, prevents the mid-summer scramble of trying to find space for everything at once.
Successive short sowings every two weeks — particularly of spinach and lettuce — smooth out the harvest curve and prevent the feast-or-famine cycle that catches many new growers off guard. A well-timed March start, followed by two or three further sowings into April, produces a steady stream of salad and greens right through late spring and early summer.
Estimated Cost
| Item | Approximate Cost (USD) | Approximate Cost (GBP) |
|---|---|---|
| Seed packets (5 varieties) | $10–$18 | £8–£14 |
| Seed compost (10 L bag) | $8–$12 | £6–£10 |
| Horticultural fleece (5 m roll) | $10–$15 | £7–£12 |
| Plug trays (pack of 4) | $5–$8 | £3–£6 |
| Bamboo canes or pea netting | $8–$14 | £5–£10 |
| Estimated total | $41–$67 | £29–£52 |
Frequently Asked Questions
Can I sow these vegetables if I only have containers or raised beds?
All five crops grow well in containers and raised beds, provided the depth is adequate. Peas and broad beans need at least 30 cm (12 inches) of depth for their root systems; spinach, lettuce, and kale (especially at the seedling stage) do well in as little as 20 cm (8 inches). Use a good-quality peat-free multipurpose compost, and ensure containers have drainage holes — waterlogging is the primary risk in early spring container growing. Raised beds warm slightly faster than open ground, which can give you a few days' head start on germination.
What if there's a hard frost forecast after I've sown?
A light frost — down to about -2°C (28°F) — won't damage established seedlings of any of these five crops, and seeds already in the ground are generally protected by the soil itself. For more severe late frosts, cover rows with two layers of horticultural fleece or bring trays indoors overnight. The real risk is a prolonged cold snap combined with wet soil, which can cause rotting at the stem base (known as damping off in seedlings). Good drainage and avoiding overwatering are your best defences.
How do I know when to harvest each of these crops?
Spinach and lettuce are ready to harvest as soon as individual leaves reach a usable size — typically 8–12 cm (3–5 inches) for spinach, and whenever the lettuce forms a loose head or the outer leaves are large enough to use. Peas are at their sweetest when the pods feel plump and the seeds inside are visible as distinct bumps along the pod. Broad beans are best picked when pods are bright green and firm, before the skin around each bean develops a tough, dark scar. Kale can be harvested leaf by leaf from the outside of the plant once leaves reach 15–20 cm (6–8 inches); avoid stripping the central growing tip.
Do I need to feed these crops during the growing season?
In well-prepared soil enriched with compost before planting, most of these crops need little additional feeding. Peas and broad beans are nitrogen fixers — they have root nodules that extract nitrogen from the air and store it in the soil, actually improving fertility for follow-on crops. Kale and spinach benefit from a balanced liquid feed every two to three weeks once actively growing, particularly if planted in containers where nutrients deplete faster. Avoid high-nitrogen feeds for peas and beans, as this encourages leafy growth at the expense of pod production.
Can I direct sow all five outdoors, or do some need to be started indoors?
Peas, broad beans, and spinach are best direct sown outdoors where they will grow, as they dislike root disturbance during transplanting. Lettuce and kale transplant readily and are well suited to being started indoors in trays, then moved outside once large enough. Starting lettuce and kale indoors in late March also lets you control germination conditions more precisely and protects young seedlings from slugs during their most vulnerable stage.