March is one of the busiest and most exciting months in the UK gardening calendar. As daylight hours increase and soil temperatures begin to rise, gardeners can finally move from planning to action.
For many growers, March marks the true beginning of the growing season. Seed trays fill up, allotments come back to life, and garden beds begin producing the first crops of the year. Whether you're growing vegetables on an allotment, managing raised beds, or cultivating crops in containers, March offers a huge range of sowing opportunities.
In this guide, we'll cover exactly what to sow in March in the UK, including vegetables, herbs and flowers that can be started indoors and outdoors.
Quick Answer: What Can You Sow in March?
March is one of the most productive sowing months of the year. Popular crops to sow in March include:
Many gardeners can now start direct sowing outdoors, depending on local weather conditions.
Vegetables to Sow in March
Carrots
March is one of the most popular months for sowing carrots.
For best results:
- Sow directly where they will grow
- Use stone-free soil
- Avoid transplanting
Popular varieties include: Nantes, Early Nantes, Autumn King, Chantenay.
Beetroot
Beetroot is easy to grow and can be sown directly outdoors throughout March.
Benefits include:
- Reliable germination
- Quick growth
- Multiple harvest opportunities
Popular varieties: Boltardy, Detroit Globe, Chioggia.
Parsnips
March is often considered the ideal month to sow parsnips. They require deep soil, consistent moisture and patience — remember that parsnips can take several weeks to germinate.
Radishes
One of the quickest crops you can grow. Many varieties are ready to harvest within four to six weeks.
Spring Onions
A simple and productive crop for beginners. Successional sowing every few weeks provides a continuous harvest.
Lettuce
March is an excellent month for lettuce sowing. Try Little Gem, Salad Bowl, Lollo Rosso and romaine varieties.
Spinach
Spinach thrives in cool spring weather. March sowings often provide excellent crops before summer temperatures arrive.
Peas
Peas can now be sown outdoors in many areas. Popular varieties include Kelvedon Wonder, Meteor and Hurst Green Shaft.
Broad Beans
Broad beans can continue to be sown throughout March. They are among the most reliable vegetable crops for UK gardeners.
Turnips
Fast-growing and often overlooked, turnips are ideal for early sowing.
Brassicas to Sow in March
March is a key month for starting many brassica crops.
Cabbage
Summer cabbage varieties can be sown now.
Kale
A productive crop that can provide harvests for many months.
Brussels Sprouts
March sowings give plants plenty of time to mature before winter harvests.
Cauliflower
Early sowings can produce crops later in the year.
Broccoli
Calabrese and sprouting broccoli can both be started during March.
Indoor Sowing in March
Although outdoor sowing becomes possible for many crops, some vegetables still benefit from being started indoors.
Tomatoes
March is arguably the most popular month to sow tomatoes in the UK. Popular varieties include Gardener's Delight, Sungold, Alicante and Shirley.
Sweetcorn
Starting sweetcorn indoors provides a useful head start.
Courgettes
Late March is an excellent time to begin sowing courgettes under cover.
Cucumbers
Greenhouse cucumbers can be started indoors towards the end of the month.
Squash and Pumpkins
Some gardeners begin these crops indoors in late March.
Herbs to Sow in March
Parsley
Reliable and productive throughout the growing season.
Coriander
Successive sowings help provide continuous harvests.
Dill
Ideal for vegetable gardens and wildlife-friendly planting schemes.
Chives
Easy to grow and useful in both containers and borders.
Basil
Can be started indoors during March for summer planting.
Flowers to Sow in March
Sweet Peas
March remains one of the best months to sow sweet peas.
Cosmos
A favourite among pollinators and gardeners alike.
Sunflowers
Easy to grow and ideal for children.
Nasturtiums
Beautiful, edible and excellent for companion planting.
Cornflowers
Perfect for wildlife-friendly gardens.
Calendula
Easy to grow and useful for attracting pollinators.
Nigella
A cottage garden classic with attractive seed heads.
What Can You Plant Outdoors in March?
As conditions improve, gardeners can begin planting:
- Onion sets
- Shallot sets
- Garlic
- Rhubarb crowns
- Fruit bushes
- Bare-root plants (early March)
Always monitor local weather forecasts, particularly in northern regions where frost remains a risk.
MyGrowPal flags frost-risk days on your growing calendar. Set your UK postcode and the app adjusts planting-out dates to your local conditions — essential when a warm March week is followed by a sudden cold snap.
March Gardening Jobs
March is often one of the busiest gardening months.
Prepare vegetable beds
Remove weeds and add compost, well-rotted manure and organic matter.
Start succession planning
Many crops benefit from sowing every few weeks — lettuce, radishes, beetroot and spring onions are prime examples.
Install supports
Prepare structures for peas, beans and sweet peas before plants need them.
Protect young seedlings
Cold nights remain common. Keep horticultural fleece, cloches and cold frames available for sudden temperature drops.
Check watering needs
Warmer days can dry seed beds surprisingly quickly.
Common March Sowing Mistakes
Sowing Into Cold Soil
While enthusiasm is high, cold soil can slow germination dramatically.
Forgetting Succession Sowing
Many gardeners sow everything at once and end up with a glut later.
Ignoring Frost Forecasts
March weather can be unpredictable. A warm week can quickly be followed by freezing temperatures.
Starting Too Many Tomatoes
It's tempting, but many gardeners end up with more plants than they can realistically grow.
Using MyGrowPal to Plan March Sowing
March is often when gardeners begin juggling dozens of sowing dates, seed packets and garden tasks. MyGrowPal is designed to reduce that mental load.
Frequently Asked Questions
Is March the best month to start a vegetable garden?
For many UK gardeners, yes. March offers one of the widest ranges of vegetables that can be sown.
Can I sow carrots in March?
Absolutely. March is one of the most popular months for sowing carrots.
Is it too late to sow tomatoes in March?
No. In fact, March is often considered the ideal month for sowing tomatoes in the UK.
What flowers can I sow in March?
Cosmos, sweet peas, sunflowers, calendula, cornflowers and nasturtiums are all excellent choices.
Can I sow seeds directly outdoors in March?
Many vegetables can be direct sown outdoors during March, depending on local weather and soil conditions.
Final Thoughts
March is the month when the growing season truly takes off. With increasing daylight, warming soil and a huge variety of crops ready for sowing, it's one of the most rewarding times of year for UK gardeners.
By combining direct sowing outdoors with protected indoor sowings, you can establish the foundations for months of productive harvests. And if you're managing multiple crops, beds and sowing schedules, MyGrowPal can help keep everything organised — from seed packet scans and weather-aware reminders to harvest logs and garden planning tools — so you never miss an important gardening task.