Preparation is key this month. Prepare beds for sowing; organise the greenhouse; buy in new seed compost (see how make your own) and order seeds if not done so already.
See below for advice on soil, vegetables, fruit, herbs and flowers as well as keeping the growing area healthy. Lawns and ponds also need attention this month. Plus what to sow and plant in March and Vegetable Growing Cards for advice.
Soil and composting 🔗
- Good soil structure is the key to growing healthy vigorous plants. If your soil is still wet from winter rains, avoid walking or standing on it until it's had a chance to dry out. Use planks to spread your weight.
- Once temperatures warm up, spread compost, well-rotted manure or other soil- improvers onto the soil. The organic material will stimulate the billions of micro-organisms that maintain health and fertility.
- If you know you have a patch which won't be cultivated until later in the summer, sow a green manure to benefit the soil. Fenugreek or Phacelia tanacetifolia will germinate this month. The former gives the soil a quick fertility boost, the latter will provide beautiful blue flowers loved by pollinators. See Green Manures to understand how they work. The Organic Gardening Catalogue has a wide range of green manure seeds, suitable for every soil type and situation.
- Give your compost heap a 'spring turn' to aerate and stimulate the contents. But if you heap is open, take care - hedgehogs, slow worms and other creatures often creep in to hibernate. Check you are not disturbing them before turning the contents. See Home Composting
- March is also a good month to empty out any compost that is already will rotted. Store in bags ready for use around the garden where needed.
- If you have a worm bin, it can be put outside at the end of the month.
- Use this month to pre-warm soils with a cloche or sheet of plastic for a week or two before sowing or planting.
- 'Top dress' overwintered crops, such as autumn-planted onions and cabbage, with some rich garden compost, or well-rotted manure. This will give them a boost for spring growth.
- Don't forget to plan a crop rotation for your fruit and veg. This helps prevent disease and makes best use of the soil's nutrition. See Planning Your Planting.
- If you have had rye growing as a green manure over winter, it is important not to follow it with a direct-sown, small-seeded crop, such as carrots or parsnips. The decomposing rye foliage can temporarily inhibit germination. Wait 2 or 3 weeks after digging the rye in, then sow. See Green Manures.
- Dig up any potato plants from tubers left in the ground from last year, they could be carrying the potato blight fungus. They can be composted, but smash them well first.
- Bury stems and stumps of overwintered brassicas in the compost heap as soon as they have finished cropping. This will help reduce the population of mealy aphids and whitefly which otherwise would simply move on to your spring planted crops.
- Without bees there would be no fruit, so it pays to make your organic garden bee-friendly.
- In sunny spots, sow clumps of bee-attractant flowering plants. There are lots of annuals you can sow now including borage, Californian poppy, bronze fennel, and poached egg plant. The latter is useful sown around fruit bushes to attract aphid-eating predators. They will control currant aphids, the cause of red currant blister leaf damage.
- As the soil warms up, apply mulches around/under established trees and fruit bushes. First remove existing weeds, then hoe carefully (avoiding roots) to expose pests to birds. (This is particularly useful to get rid of the gooseberry sawfly cocoons. Sawfly will eat and eventually defoliate the bushes.) Wait a few days, then mulch with well rotted manure, garden compost or straw and hay (up to 10cm deep).
- It is so easy to grow your own organic herbs. Many are annuals, growing from seed each year. Check out the Herb Growing Cards to help you get growing.
- If your soil is heavy and water-retaining, lightly fork in some horticultural grit over the whole area, to improve drainage.
- Perennial herbs will benefit from some garden compost or rotted manure.
- Hard-prune roses and clear away lingering dead leaves to clear away remaining black-spot spores.
- Give established roses, herbaceous plants, climbers and bulbs a spring feed with garden compost. If you only have farm manure, make sure it’s well-composted, use at half the rate of garden compost, and keep away from plant stems. Fork in lightly, or just leave on the soil surface and let soil creatures take it down.
- Whatever you plant this month, tree, shrub, or perennial, don’t over-feed. A couple of handfuls of garden compost in the planting hole is enough, plus a light mulch around the newly-planted.
- Hoe weeds on sight, especially annual weeds before they can seed.
- If a frost is forecast, be sure to protect any tender plants. See Frost in the Garden
Keeping the growing area healthy 🔗
- Aphids of all sorts will be on the increase this month. Before summer predators such as ladybirds and wasps are ready to eat them, use hand picking/squishing to control an infestation build-up, rather than resort to toxic sprays.
- Flowers in all parts of the garden will attract beneficial predators, such as hoverflies, and thus avoid the need for harmful pesticide sprays. The poached-egg flower, Limnanthes douglasii will provide an early feast. The sooner you fill your garden with the pest-eaters, the sooner you'll get the pests under control.
- Insects to encourage are ladybirds (will eat aphids), beetles (will eat slugs) and wasps - which will devour hundreds of grubs and flies in the course of a summer. A healthy garden is filled with a huge range of wildlife, ugly and beautiful, a balance that keeps the garden flourishing.
- Cut out any branches showing signs of coral spot and clear away dead plant tissue where this disease can take hold. Dieback appearing on woody plants after the cold season should also be cut out, down to healthy growth.
- Put out slug traps a week or two before making new sowings and plantings and check them regularly - especially in damp weather - to keep topped up with bait such as beer or formulated bait.
- Make sure your greenhouse is clean and washed down.
- Hang sticky traps to catch flying pests such as whitefly and sciarid fly. Temperatures are too still too low for biological control, so traps will keep pest levels down until predators can be introduced.
- Squash or rub off aphid colonies as they arrive.
- Carefully remove any decaying plant debris.
- Frogs will arrive soon to breed. Make sure they have plants nearby to shelter in.
Lawns and hedges
- Feed your organic lawn if it grew poorly last year. Try organic lawn feed from The Organic Gardening Catalogue
- Alternatively, scatter sieved garden compost over the lawn, and brush or rake in.
- A patch of unmown long grass adds to the bio-diversity in your organic garden. Butterflies, for instance, like to lay eggs in flowering grasses.
- Feed any hedges with a garden compost, or well-rotted manure mulch.
- If plants start to put out new leaves, you can start feeding again. Fertiliser sticks, or Chase Organic SM3 Seaweed Extract are ideal and flowering house plants can also be fed with Organic Tomato Feed. All these products are available from The Organic Gardening Catalogue.