After the heavy rains in February and a flood in the vegetable garden, we’re starting March with a bit of a delay. Fortunately, we dodged serious damage and now the soil is warming as the weather slowly turns to spring — albeit later than usual.
At the moment, weeds are exploding in the garden. Because of the rains and the flooding, we couldn’t do much in the garden, so we have a lot of catching up to do.
Across many parts of the world, especially in much of the USA and Northern Europe, cooler conditions still prevail and garden work is quietly waiting for the soil to warm up.
Here’s what to do in and for the vegetable garden this month — both for warm, Mediterranean climates like Monchique and for gardeners still battling late frost or slow soil warming up north.
What to Do in the Vegetable Garden in March (Milder Climate)
☀️ Get Your Plots Ready
Weeds will quickly take over the garden now. Luckily, the soil is still damp and soft, so clearing them away is easy. Don’t wait until the soil dries and becomes hard.
Clear debris, weeds, and leftover crops from winter. Prepare the beds for seedlings or for sowing — whichever comes first.
That means the potato bed needs to be ready for planting.
The same principle applies to the onion and beetroot beds (which we plant together in one bed). Next to the onions, sow carrots, since they are excellent companions. Add a row of leeks as well.
Make sure the prepared bed is large enough to give them all space. All these crops (other than the potatoes) need very little compost. If you composted your plot last year, you can skip composting them altogether.
It certainly won’t harm to clear the rest of the garden from weeds. If the soil still needs to wait more than three or four weeks before planting, green manure can fill the gap.
Mustard seeds, phacelia, and (fodder) lupines all do a great job as green manure.
Potatoes Like Compost on Their Head
For potatoes, it’s a different story. They like a lot of compost and can even tolerate fresh manure from horses or cows.
Here is how you do it: Make a 20 cm deep trench along the length of your bed. Place the potatoes every 30 cm, give them a good scoop of compost, and close the trench with soil. Mark the row well. Leave 50 cm before digging the next trench, then repeat the procedure.
When the potatoes show their first leaves, mound them up so you just cover the leaves. Wait for the leaves to appear again and mound them up once more. Your potato rows will form raised ridges with a trench between the rows.
🥔 Potatoes — It’s Go Time
You’ve already bought your potatoes — great!
Before putting your potatoes in the ground, cut the seed potatoes so that each piece has a few sprouts. This is especially important when you bought larger seed potatoes with multiple eyes (potential sprouts).
After cutting, let the pieces dry and form a protective callus layer — this reduces the risk of disease when planted.
Then place them in your trench.
🥬 Planting and Sowing in Mild Climates
This Monday the big market near Monchique (São Teotónio) takes place again, like every first Monday of the month.
Plants to Buy and Plant in March
Lettuce, beetroot, and onions (I like the Valencia variety; they store well) are available now. Since you have already prepared the bed, plant them directly into the soil. If you still need to prepare your bed, don’t wait too long — the plants keep for about a week, but not much longer.
If you find them at the market, plant fast-growing leafy greens like spinach and quick-maturing cabbage types as well.
(If you have already pre-seeded these vegetables — that’s perfect for planting this month.)
What to Sow in March (Mild Climate)
Sow carrots directly into the soil. I love Rodelika and Jaune du Doubs from Sementes Vivas. Towards the end of the month, add a row of parsnips.
In your greenhouse, start sowing all the summer crops this month (no hurry, you have the whole month):
Tomatoes, aubergines, peppers, pumpkins, cucumbers, piri-piri, paprikas, courgettes.
🌱 Seeds to Sow in March for Cooler Climates
For gardeners in northern Europe, the USA, or cooler micro-climates:
Most crops still start indoors. In Holland, we used to place our seed trays on the windowsill, right above the central heating by the window. This saves the need for a heated greenhouse. Without central heating, the windowsill itself might be just right. If it feels too cold because it’s too far from the heating, use a heating mat under the pots.
You can already sow fava beans and peas outside, but we always pre-grew them on our windowsill. When sown outside as the first greens in the garden, pigeons would completely go for those tender shoots.
Once the plants were slightly bigger and it was later in the year, we experienced less damage.
Sharp-seeded spinach, however, performs well when sown outside in March, and even in February when the weather is mild.
Sow endive (chicory — the leafy type), cauliflower, and lettuce indoors as well.
Start leek and pepper plants early too, because these two take a very long time to grow into strong transplantable plants.
🌼 In Summary: What to Do in the Vegetable Garden in March
March is a month of preparation and momentum.
After heavy rains and flooding, gardeners in milder climates like Monchique focus on clearing weeds, preparing beds, and planting early crops such as potatoes, onions, beetroot, carrots, and lettuce. Potatoes need extra compost and careful mounding, while most other early crops require only lightly enriched soil. Green manure can fill empty beds if planting is delayed.
In cooler climates, March is largely about starting seeds indoors — using windowsills, heating mats, or protected spaces — while hardy crops like peas, fava beans, and spinach can already go into the ground. Protecting young seedlings from birds and cold remains important.
Whether you are gardening in the Algarve, Portugal or further north, March is the month when the garden slowly wakes up — and so do we.
Happy gardening! 🌱🌞
