When to Plant Leeks?

Leeks are a popular vegetable in the vegetable garden, but the right time to plant them can be confusing. It depends on the type of leek (summer or winter leek), the climate, and whether you're sowing your own seeds or transplanting seedlings. Below, you'll discover the best time to plant leeks and what to look out for.

When can you sow leeks?

Leeks can be sown at different times, depending on the type of leek:

• Summer leek: sow from February to April
• Autumn leek: sow from March to May
• Winter leek: sow from March to June

If you sow early in the year, this is usually done under glass or in a sheltered environment (greenhouse, cold frame, or windowsill). From April onwards, you can often sow directly in the ground, provided the soil has warmed up sufficiently.

When is the best time to plant leeks?

After sowing, first cultivate the seedlings in a seedbed or pots. Once the leeks have reached about the thickness of a pencil, you can transplant them. Here are the guidelines:

• Planting summer and autumn leeks: from April to June
• Planting winter leeks: from June to July

When planting, dig deep holes (10–15 cm) to encourage long, white stems. Plant on a cloudy day or in the evening to prevent sunburn.

What temperature is suitable for planting leeks?

Leeks are quite hardy and can withstand cold well, but young plants are more sensitive. Keep the following in mind:

• Soil temperature ideally above 7–8°C
• Air temperatures between 10 and 20°C during planting

Leeks can usually tolerate late frosts, especially winter leeks, but prolonged frost immediately after planting is less beneficial. Protect young plants with fleece if a hard frost is likely.

What is the difference in planting time between summer and winter leeks?

The big difference is in the moment of harvesting and therefore also the planting time:

• Summer leek : faster growth, planted in spring , harvest in summer to early autumn .
• Winter leek : grows more slowly, planted in early summer , harvest in late autumn and winter .

Winter leeks are hardier and can be left in the ground during the cold months, while summer leeks are more sensitive to frost and are usually harvested earlier.

When can you buy and plant leek plants?

If you don't want to sow your own seeds, you can buy leek seedlings from garden centers or growers. These are usually available:

• Summer leek plants: from April
• Autumn and winter leek plants: from May to July

Plant the purchased plants as soon as possible, preferably on a day that isn't too hot. Make sure the roots don't dry out during transport and waiting.

How can you prepare the soil before planting leeks?

Good soil preparation is important for strong, healthy leeks. Note the following:

• Structure: airy, well-drained soil
• Feeding: Leeks are voracious eater; work in well-rotted compost or old manure in the spring.
• pH value: slightly neutral soil (pH 6–7) is ideal

Avoid fresh manure just before planting, as this can adversely affect growth and flavour and lead to increased weeds.

What planting distance should you maintain when planting leeks?

The planting distance partly determines the thickness of your leeks. A common layout:

• In the row: 10–15 cm between the plants
• Between rows: 30–40 cm

For thicker stalks, you can allow a little more space, and for thinner, denser leeks, a little less. Maintain these spacings for sufficient light and airflow, and to reduce the risk of mold.

Can you grow leeks after other crops in the same season?

Leeks are well-suited for subsequent cultivation after early crops. Possible combinations:

• After early potatoes
• After spinach or other leafy greens that are harvested early
• After radish or lettuce in spring

Plan your crop rotation carefully: don't plant leeks in exactly the same spot every year to prevent diseases in the soil.

When can you harvest leeks after planting?

The harvest time depends on the type and the time of planting:

• Summer leek: about 3–4 months after planting
• Autumn leek: about 4–5 months after planting out
• Winter leek: about 5–7 months after planting out

You can usually harvest leeks gradually. With winter leeks, you simply leave some in the ground and harvest as needed throughout the winter, as long as the ground isn't frozen solid.

What else should you pay attention to when planting leeks?

Some additional points to consider regarding planting time:

• Watering: Water generously immediately after planting, especially in dry weather.
• Hilling up: To get longer white stems, you can hill up the soil around the plants during growth.
• Protection: Young plants can be attacked by leek fly; a fine-mesh insect screen can help.
• Sunlight: leeks like a sunny to partially shaded location.

When is planting leeks in your garden most successful?

Ultimately, the ideal planting time depends on your region, the soil, and the weather in any given year. As a rule of thumb:

• Sow between February and June , depending on the type of leek.
• Plant out from April to July , when the soil is warm and the plants are strong enough.

By considering the correct sowing periods, planting dates, and growth habits of summer and winter leeks, you increase the chance of a bountiful harvest of tasty, firm leeks from your own garden.