March is when the UK growing season properly begins. The days are getting longer, the soil is starting to warm up, and there's a buzz in the air that makes you want to get outside and get your hands dirty. Whether you've got a full allotment or just a few pots on a patio, now is the time to start sowing.
But if you're new to growing, the sheer number of seed packets at the garden centre can be overwhelming. So here's a straightforward guide to what you can sow right now — split into indoor and outdoor options.
What to Sow Indoors in March
Starting seeds indoors gives them a head start before the last frosts pass (usually around mid-May in most of the UK). A sunny windowsill, a conservatory, or even a cheap propagator will do the job.
Tomatoes
Sow into small pots on a warm windowsill. They'll be ready to plant out in late May.
Chillies & Peppers
Need warmth to germinate. Start early March for a summer harvest.
Courgettes
Fast growers. Sow individually in pots from mid-March onwards.
Broccoli
Sow in modules indoors, then transplant out once they're sturdy enough.
Aubergines
Like peppers, they need warmth. Start on a heated mat or sunny sill.
Basil
Sow indoors and keep warm — basil hates the cold. Don't put outside until June.
What to Sow Outdoors in March
Some hardy crops can go straight into the ground or into outdoor pots from March, though it's worth checking your local conditions — the north of England and Scotland may need to wait a couple of weeks longer than the south.
Carrots
Sow directly into the ground from mid-March. Thin them out as they grow.
Peas
Hardy enough for March sowing. Pop them straight into the soil or a deep pot.
Spinach & Lettuce
Quick to germinate and happy in cooler weather. Great for pots too.
Onion Sets
Push sets into the ground with the tip showing. Easy and reliable.
Potatoes
Plant out "first early" varieties from mid-to-late March in milder areas.
Broad Beans
Very hardy. Direct sow from early March — they'll handle a light frost.
A Few Things to Keep in Mind
March weather in the UK is unpredictable. One day it's warm and sunny, the next it's sleeting. Don't panic — most seeds are tougher than you think, and the ones you're starting indoors are safely tucked away from the worst of it.
If you're starting small, pick three or four things that excite you and focus on those. There's no prize for sowing everything at once, and it's much better to do a few things well than to spread yourself too thin.
And if you've got pots rather than beds, that's absolutely fine. Tomatoes, herbs, chillies, lettuce, and even carrots grow brilliantly in containers. You don't need a huge garden — just a bit of sunshine and some enthusiasm.
What Comes Next
Once your March sowings are underway, April opens up even more options — runner beans, sweetcorn, squash, and more. But for now, get those seeds in and enjoy the process. There's nothing quite like watching the first green shoots appear and knowing you made that happen.
Happy sowing! 🌱