Month by month
Garden jobs for March: sowing, planting and pruning
March is when the garden wakes up, though it rarely does so politely. Warm, sunny afternoons can be followed by hard frosts, cold winds and even late snow, especially in the north and in frost pockets. As a rough guide, soil in southern England and coastal Ireland is often warm enough for hardy sowings by mid-March, while gardens in Scotland and the north of England may need to wait until April. A simple test: if weeds are germinating, the soil is warm enough to sow. This is a busy month, so make a list and tackle jobs on the good days.
Flowers and borders
Now is the ideal time to lift and divide clumps of summer-flowering perennials that have become congested or bare in the middle. Plants such as hardy geraniums, Michaelmas daisies and catmint respond well. Dig up the clump, split it with two forks back to back or a sharp spade, discard the woody centre and replant the vigorous outer pieces with some compost.
Prune bush and shrub roses before the buds fully break. Take out dead, diseased and crossing stems, then shorten the remaining strong shoots to an outward-facing bud. Hybrid teas can go back to about 15–20cm; shrub roses need only a light trim to shape. Our rose guide covers the different groups.
In northern gardens, prune buddleja hard now if you did not in February. Cut back the flowered shoots of winter heathers with shears. Trim lavender lightly later in the month, never cutting into bare wood, which rarely regrows.
Once the soil is moist and starting to warm, spread a 5cm mulch of compost, bark or leaf mould over bare soil between plants. It locks in moisture and suppresses weeds. Put supports in place for tall perennials such as delphiniums and peonies now, so the plants grow through them. Our mulching guide explains which material suits which plants.
Vegetables
Plant first early potatoes in milder areas towards the end of the month, about 12cm deep and 30cm apart, and be ready to cover emerging shoots with soil or fleece if frost threatens. Onion and shallot sets go in now, with their tips just showing. Birds love to pull them out, so cover with netting until they root.
Outdoors, sow broad beans, peas, parsnips, spinach, radishes, lettuce, spring onions and summer cabbages once the soil has warmed. Use cloches in colder regions. Indoors, carry on sowing tomatoes, peppers and celeriac, and start brassicas such as Brussels sprouts and cauliflowers in modules for planting out later.
Weed beds thoroughly before sowing, as small weeds are far easier to deal with now than in May.
Fruit
Finish planting bare-root fruit bushes and trees early this month, before buds break. Feed and mulch established ones. Prune newly planted gooseberries and red currants to an open goblet shape. Protect blossom on early-flowering apricots, peaches and nectarines with fleece on frosty nights. Strawberry beds benefit from a tidy: remove dead leaves and runners, and top-dress with compost.
Lawns
The lawn starts growing as the soil warms, usually mid-March in the south and a few weeks later further north. Make the first cut with the blades set high, and simply top the grass; lower the height gradually over the next few weeks. Rake out moss and dead thatch with a spring-tined rake once the grass is growing, and spike compacted areas with a garden fork. Hold off on feeding until April, when growth is strong enough to use it.
Wildlife
Frog and toad spawn appears in ponds now, so avoid disturbing the water. Leave a section of the garden a little untidy, as many beneficial insects are still emerging from hollow stems and leaf litter. Hedgehogs come out of hibernation hungry; a shallow dish of water and meaty cat food helps. Keep feeders topped up, as there is still little natural food, and avoid cutting hedges once birds begin nesting. Flowering pulmonaria and early crocuses feed hungry bees.
Indoors and under cover
Prick out seedlings sown last month into individual pots as soon as they can be handled by a leaf, never the stem. Sow half-hardy annuals such as cosmos and tender vegetables in a heated propagator. Pot up dahlia tubers if you have not already. Pinch out sweet peas and harden off autumn-sown ones in a cold frame ready for planting out in April. On bright days the greenhouse can overheat quickly, so ventilate and start damping down.
Plants looking good this month
March is the start of the big spring show:
- Daffodils fill borders and grass with yellow and cream.
- Forsythia lights up hedges and shrub borders.
- Camellias are in full flower in acid soil.
- Pulmonaria and brunnera bring blue to shady corners.
- Bergenia sends up pink flower spikes above its glossy leaves.
- Hellebores carry on flowering for weeks.
- Crocuses are finishing in the south and peaking in the north.
Missed something? Check February jobs, then look ahead to April jobs.
From the plant finder
In flower in March
Good time to plant
Due for pruning
Grow your own in March
Sow now
Plant out
Ready to harvest
Problems to watch for in March
Spotted something else? Diagnose it by symptom.