Sow in April: what to plant in the vegetable garden this month?

In this article 8 ⌄

April is the month when we make the most mistakes in the vegetable garden — precisely because it makes us want to get started. The first beautiful days arrive, we take out the seed packets, and sow species that won't emerge for three weeks, if they emerge at all.

The cause is always the same: we sow according to air temperature, whereas it is the soil temperature that determines the outcome. In April, the gap between the two is at its greatest of the year.

The rule of the month: read the soil, not the calendar

A soil thermometer costs a few euros and replaces all the calendars. Plant it 5 cm deep and take the temperature in the morning, not in the afternoon.

Soil temperature	What germinates
5-8 °C	Peas, broad beans, spinach, radishes, lamb's lettuce, early carrots
8-12 °C	Lettuce, beets, onions, leeks, cabbage, parsnips, turnips
12-15 °C	Beans, corn, squash, zucchini, cucumber
18 °C and above	Tomatoes, peppers, eggplants, basil, melons — under cover only in April

The classic mistake this month: sowing beans on the first beautiful weekend. The air reads 20 °C, the soil is at 9 °C, and the seeds rot without emerging. Wait until the end of the month, or even May. A bean sown ten days later catches up within a week.

Details of the sowing methods are in How to sow your seeds.

What to sow outdoors

From the beginning of the month

• Radishes — 18 to 25 days. Sow a short row every two weeks rather than a whole row: this is the principle of succession sowing.
• Carrots — sow thinly in finely crumbled soil, and be patient: three weeks to emerge. Sow a few radishes in the same furrow to mark the row.
• Spinach, cut-and-come-again lettuce, arugula, watercress — short cycles, harvest from May.
• Peas and broad beans — if you haven't already done so in autumn.
• Beets, turnips, parsnips — parsnips are slow to emerge; don't give up before three weeks.
• Onions, shallots — from sets.

Toward the end of the month

• Dwarf beans — only if the soil reaches 12 °C, and in mild regions.
• Squashes, zucchini, cucumbers — in planting pockets under fleece, or better: in pots to transplant in May.
• Flowers — marigold, borage, cosmos, nasturtium. Sow now so they are in bloom when the aphids arrive — it's a question of timing, not decoration. See Combining flowers in the vegetable garden.
• Green manures — phacelia on beds that will not be occupied until June.

What to sow under cover

April is the last useful time to start long-cycle fruiting vegetables.

• Tomatoes — if you haven’t done so in March, sow now. They need 18–20 °C and, above all, plenty of light as soon as they emerge. See Heirloom tomato seeds.
• Peppers, chili peppers, eggplants — it is already late: their growing cycle is longer than that of tomatoes. Sow without delay, in warmth.
• Basil — at least 18–20 °C. See Basil seeds.
• Squash and cucumbers — in pots, three weeks before planting. Don’t sow too early: an overgrown squash plant does not recover well.

The trap with April seedlings started indoors: keeping the plants warm after they emerge. Warmth is for germination, while light is for growth. As soon as the cotyledons emerge, lower the temperature and provide as much light as possible — otherwise you will get leggy seedlings that will never catch up.

The late-frost trap

April creates a false sense of security. Late frosts are common until mid-May across much of France, and they occur mainly on a clear, windless night — the night after a beautiful day.

• Do not plant anything frost-sensitive until the risk has passed: tomatoes, zucchini, basil, beans. A frost-damaged plant is lost, not merely delayed.
• Keep a row cover close at hand — it raises the temperature by 2 to 4 °C, which is enough in most cases.
• Beware of hollows and the bottoms of slopes, where cold air accumulates at night. See Planning according to zones and exposure.
• Harden off your plants one week before planting: take them outside for a few hours each day, sheltered from the wind. A plant moved directly from the house into the open air loses two weeks.

Other tasks for the month

• Destroy winter green manures — mow before they go to seed and leave them in place as mulch. Allow two to three weeks before sowing on this bed. See Sowing green manures.
• Thin March seedlings — it’s thankless but decisive. Cut them with scissors rather than pulling them out.
• Mulch once the soil has warmed up — but not before: mulch applied too early keeps the soil cold and delays everything.
• Install stakes before the plants need them.
• Watch out for slugs — April is their month. Collect them in the evening, use dry barriers, and above all provide shelters for ground beetles, which keep them in check.

The five mistakes to avoid in April

1. Sowing according to the air temperature. The soil lags several weeks behind the air. A thermometer settles the matter.
2. Sowing everything at once. Twenty radishes every two weeks are better than a hundred on the same day.
3. Putting the plants outside too early. A late-April frost can destroy a month’s worth of seedlings.
4. Working waterlogged soil. Wait until it has dried sufficiently: a squeezed handful should not release water and should crumble when you open your hand. Walking on waterlogged soil compacts it for the season.
5. Mulching too early. Let the sun warm the soil first.

Frequently asked questions

Is it too late to sow tomatoes in April?

No, but this is the last comfortable window. You will harvest two to three weeks later than with a March sowing, which is still more than sufficient. For peppers and eggplants, however, it is truly too late.

Can you sow directly instead of transplanting?

For anything with a taproot—carrots, parsnips, radishes, and beets—it is even mandatory. For fruiting vegetables, sowing in pots remains preferable in April: you can control the temperature.

How do I know if the soil is warm enough?

Use a soil thermometer at a depth of 5 cm in the morning. Failing that, an old indicator: when dandelions bloom en masse, the soil is around 10°C; when lilacs bloom, it is approaching 15°C.

Should I water in April?

Yes, water newly sown seeds with a fine, regular spray: a seed that swells and then dries out will die. Established crops rarely need watering—the soil's winter reserves are still there.

What should I do if it freezes after I sow?

Seeds in the ground are generally safe. It is the newly emerged seedlings that suffer. Cover them with a row cover, cardboard, or an upside-down bucket in the evening, and remove it in the morning.

Key takeaway

Rely on soil temperature rather than the calendar, sow in batches rather than all at once, and keep a row cover close at hand until mid-May. April rewards patience: the ten days you think you lose by waiting can be made up in a week of growth.

To take things further

• The month-by-month sowing calendar
• How to sow your seeds in cotton, pots, or directly in the ground
• Fall vegetable garden: what to sow and when to harvest?
• The best vegetable combinations for the garden

Discover our collection of spring sowing seeds, our vegetable seeds, and our bee-friendly plants.