What to Plant in March: The Complete Sowing Calendar

March is the month that changes everything in the garden. Daylight increases fast, the soil begins to warm, and suddenly there is a long list of things that can — and should — go in the ground. Whether you are starting seeds on a windowsill or sowing directly outdoors, March offers the widest range of planting opportunities of any spring month. Here is your complete guide to what to plant in March across European climate zones.

Early March: Indoor Sowing

The first week or two of March is prime time for starting warm-season crops indoors, especially if you did not get to them in February.

• Tomatoes — if you missed the February window, early March is your last good chance. Sow in modules at 20–22 °C.
• Cucumbers — sow individually in small pots. They grow fast and will be ready to plant out by late May.
• Courgettes and squash — sow from mid-March. These are vigorous growers and do not need as much lead time as tomatoes.
• Sweetcorn — sow in deep pots indoors from mid-March. Sweetcorn hates root disturbance, so use biodegradable pots you can plant directly into the soil.

Early March: Outdoor Sowing

As soon as the soil is workable and not waterlogged, several hardy crops can go directly outdoors:

• Early potatoes — chit (pre-sprout) them on a windowsill from late February, then plant in early March. Choose first-early varieties like Swift, Rocket, or Annabelle.
• Broad beans — if you did not sow them in February, early March still works well. They handle light frost.
• Peas — sow in shallow trenches or guttering. Round-seeded varieties (Meteor, Feltham First) are hardier for early sowing.
• Onion sets — push gently into prepared soil with the tip just visible. Spacing: 10 cm apart, rows 25 cm apart.

Mid-March: The Big Outdoor Push

By mid-March, soil temperatures are rising and the range of crops you can direct-sow expands considerably:

• Carrots — sow thinly in fine, stone-free soil. Cover with fleece to speed germination and protect from carrot fly.
• Beetroot — sow bolt-resistant varieties like Boltardy or Chioggia. Each seed cluster produces multiple seedlings, so thin early.
• Parsnips — sow as early as possible because germination is notoriously slow (2–4 weeks). Use fresh seed every year.
• Spinach — direct sow in rows. It prefers cool conditions, so March is ideal before summer heat triggers bolting.
• Lettuce and salad leaves — sow successionally every two weeks for a continuous harvest.
• Radishes — the fastest vegetable in the garden. Sow between slower crops as a catch crop.
• Spring onions — sow thinly in rows and harvest when pencil-thick.

Late March: Pushing the Season

In mild Atlantic (Cfb) areas, late March opens up even more possibilities:

• French beans — sow under fleece or cloches in sheltered gardens. They are frost-tender, so protection is essential.
• Sweetcorn — if you prefer direct sowing, late March works in mild regions. Otherwise, keep them indoors.
• Turnips and swede — sow directly for early summer harvests.

In continental (Dfb) zones, late March is when outdoor sowing really begins. The ground thaws and you can start with peas, broad beans, onion sets, and the hardiest root crops. Hold off on frost-tender crops until after the last frost — typically mid-May (Ice Saints).

In Mediterranean (Csa) zones, March is already well into the growing season. You can direct-sow almost everything, including French beans, tomatoes (outdoors), and warm-season herbs.

Flowers to Plant in March

March is a brilliant month for flower sowing, with options for both direct sowing and indoor starts:

Direct Sow Outdoors (Hardy Annuals)

• Cornflowers — scatter seed where you want them to bloom. They self-seed readily.
• Poppies — sow on the surface of raked soil. Do not cover — they need light to germinate.
• Calendula — sow directly. Tough, reliable, and great for attracting pollinators.
• Nigella (Love-in-a-mist) — sow where they are to flower. They dislike transplanting.

Start Indoors (Half-Hardy)

• Dahlias — sow in warmth from early March for flowers by midsummer.
• Zinnias — sow at 18–20 °C. They are fast growers and love heat.
• Cosmos — sow indoors from mid-March for transplanting after the last frost.

Herbs to Sow in March

March is the ideal month for getting a herb garden started:

• Parsley — sow indoors or under cover. Germination is slow, so be patient.
• Coriander — sow directly outdoors from mid-March. It bolts quickly in warm weather, so early sowing gives the longest harvest.
• Dill — direct sow where you want it. It does not transplant well.
• Chives — sow indoors in modules or divide existing clumps.

Trees and Shrubs: Last Call for Bare-Root Planting

March is the last reliable month for planting bare-root trees, shrubs, and hedging. Once they start leafing out (usually by April), bare-root planting becomes too risky. If you have bare-root fruit trees, roses, or hedging plants waiting, get them in the ground before the end of March.

Timing by Climate Zone

For more on how your local climate shapes your gardening calendar, see our guide to European climate zones.

Plan Your March Sowing With Plantory

March is the busiest sowing month of the year, and it is easy to lose track of what needs to go where and when. With Plantory, you can organise your sowing calendar, set reminders for each crop, and make sure nothing falls through the cracks during the spring rush.