March - Jobs to do in the garden

Top jobs
Must do jobs this month

Cut back coloured stems
Willow (salix) and dogwoods (cornus) grown for their coloured winter stems should be pruned now. Cut each stem to an outward-facing bud within 5cm of the old wood. If you want larger willows and dogwoods, prune every other year.
You can either keep your prunings to use next month as supports for herbaceous perennials or shred them to add to the compost heap. Remember to always wear gloves and safety goggles when shredding.

Deal with weeds 
Weeds will be starting to burst into growth just like everything else in the garden. A hoe makes short work of clearing a large area.
Aim to skim just below the soil surface to sever the weed tops cleanly from the roots. Always hoe on a sunny, dry day to prevent the weeds re-growing after you hoe.
When the ground is cleared, apply a layer of mulch to suppress further weed growth. We found chipped bark was good at preventing weed seedlings appearing when applied 5cm deep.

Plant summer-flowering bulbs
While their spring-flowering cousins are putting on a show, it’s time to think about planting summer-flowering bulbs such as camassia and alliums. Look out for them at the garden centre.
Check bulbs feel firm to the touch and don’t have any signs of mould. Like all bulbs, they prefer good drainage so put a handful of grit at the bottom of the planting hole.

Borders
Jobs to do now for instant results

Deadhead daffodils
Remove daffodil flowers once they've finished flowering. This will make the bulbs put their energies into next year’s display instead of making seeds. Don’t cut back the foliage yet – wait until it's turned brown when it can be easily pulled away.


Prune roses
Cut any rose bushes and hedges back by one third to a half. Cut diseased stems back to healthy growth. Prune established bush roses removing crossing, dead and damaged wood, and prune the main stems to an outward-facing bud around 15-20cm from ground level.


Jobs to do now; you'll reap the rewards later

Sow sweet peas outside 
If you didn’t have time to sow sweet peas in pots indoors earlier in the year, don’t worry – if you live in a milder area, they can now be sown outside where you want them to flower.

Take cuttings of delphiniums and lupins
Use new shoots emerging from the base of the plant and cut them from just below soil level with a sharp knife. Insert the cuttings into pots of compost – see our to find the best compost for growing on young plants. Put the pot in a clear plastic bag and the cuttings should root in a few weeks.

Lift hellebore seedlings 
Hellebores cross pollinate with other varieties and self seed readily. Dig up seedlings and pot them up to grow on – you may discover a new variety.

Protect plants from frost 
Spring is well on the way and the weather is getting warmer, but your garden can still be hit by frost in March. If frost is forecast, use fleece to protect the new leaves of hydrangea, Japanese maple and pieris. 
You can protect any emerging seedlings the same way. You should also cover the flowers of apricots, cherries, currants, peaches and plums – if they get frosted, you won’t get any fruit. For large plants, cover as many branches as you can. Uncover on frost-free days to allow pollination.

Protect plants from slugs and snails 
Prevent slug and snail attack by using barriers such as copper tape (now also with serrated edges) to protect container plants. The biological control Nemaslug (for slugs, not snails) is watered onto the soil and will work for up to six weeks. 
Copper rings, sparing use of metaldehyde pellets, Slug Clear or Growing Success Advanced Slug Killer can protect plants in the ground.

Divide plants 
Divide clumps of snowdrops and winter aconites after they've finished flowering. You can also divide herbaceous perennials and ornamental grasses such as milium, hakonechloa and calamagrostis. Lift the plant and either break the clump into two pieces (or more depending on its size) or chop it into sections with a spade. Replant the new plants without delay so they don’t dry out.

Fruit and vegtables
Vegetables

Protect early sowings 
Fleece and clear polythene can both be used to protect existing seedlings and to warm up the soil before sowing. Some vegetables – beetroot, for example – can run to seed if sown too early without protection.

Plant potatoes 
Towards the end of March plant out early potatoes, such as ‘Accent’ and ‘Red Duke of York’ that started chitting in January or February. Wait until April in cold areas. Alternatively, plant at the bottom of a large tub and gradually top up with compost (old compost is fine) as they grow, to prevent the tubers going green. Check the weight of the tub and water when it feels light.

Peas and beans
Harden off and plant out broad beans, peas, garlic and shallots raised in the greenhouse or coldframe.
Put up supports for peas and beans. You can use bamboo canes or twiggy sticks that you’ve removed when pruning.

Feed spring cabbage
Use a high-nitrogen fertiliser such as Growmore or pelleted chicken manure to give plants a boost. When you harvest the cabbages, cut them off and make a cross-shaped cut in the top of the remaining stem. This will encourage a second crop of mini cabbages to form.

What to sow
Sow broad beans, lettuce, radishes, spinach and spring onions. Towards the end of the month, sow early varieties of beetroot, Brussels sprouts, cabbages, cauliflowers and turnips.Stagger your sowings so that you don’t end up harvesting everything at once. Sow some under glass too as a precaution against pest and weather damage.

What to harvest
Harvest Jerusalem artichokes, parsnips, spring onions, leeks, winter salads, cauliflowers, spring cabbage, Brussels sprouts, chicory, kale and sprouting broccoli.


Fruit

Harvest forced rhubarb
Remove light-excluding covers. When picking rhubarb, the stems should be pulled off, not cut, as cutting can let in infection.

Early strawberries
Cover strawberry plants with cloches to encourage earlier flowering and fruiting. Open the ends of the cloches during the day to allow insects to pollinate the flowers.

Raspberry care
Cut old canes of autumn-fruiting raspberries down to ground level when new shoots start emerging from the soil. Shorten tips of summer-fruiting varieties if they have outgrown their supports. Mulch with organic material, such as garden compost, but don’t bury newly planted canes too deeply.

Lawns, ponds and greenhouses
Lawns

Remove weeds 
Use a lawn weeder or an old knife to get rid of big weeds such as dandelions.

Treat bare patches 
Prepare areas for sowing or turfing. You can lay turf now but wait until April to reseed.

Prepare grass for mowing 
If you didn’t do it in the autumn, use a spring-tine rake to remove moss and thatch (dead grass), preferably before you do your first mow. Leave the mower blades on their highest setting for the first cut.


Greenhouses

Sow veg and annuals 
In an unheated greenhouse or coldframe, sow hardy annuals, leeks, lettuces, onions and early Brussels sprouts, cabbages, cauliflowers and peas to give them a head start over outdoor sowings.

Potting and repotting
If your succulents need more space to grow, repot them in free-draining compost now. Mix the compost 50:50 with grit. Either wear thick gloves or use an old padded envelope to hold the plant when repotting sharp cacti, agaves etc.
Pot up any cuttings you’ve taken from dahlias and rooted tender perennials.

Pests
Check for greenfly and whitefly and look out for scale insects.

Ventilation
Ventilate the greenhouse or conservatory on sunny days and keep the glass as clean as possible to maximise the amount of light reaching young seedlings.


Ponds
Plan ponds and bog gardens 

Now is a good time to construct a new pond because newts and toads will be seeking new breeding grounds. 
Alternatively, you may want to fill in an existing pond leaving the liner in place and turn it into a bog garden instead. That way, you’ll still be able to grow water-loving plants but you won’t have the worry that your pond will dry out in times of drought and hosepipe bans.

Keep water clear 
Remove any remaining dead foliage from your pond. Leave it to dry at the edge so that any trapped wildlife can make its escape. Start feeding fish – little and often is best to avoid problems with algae.

Check your electrics 
Check and clean filters, pumps, water features and lighting systems.