- Soil can be warmed a few weeks before sowing seed or planting out by covering with plastic sheeting or black garden fabric.
- Clay soils need to dry out (so should not be covered in plastic sheeting, which will keep moisture in).
- Apply blood or bone meal to beds in measured amounts a week or two before planting.
- Harden-off indoor grown plants before planting outdoors. Soil temperature should be at least 7-8 degrees C before sowing outdoors. (Some guides say soil temperature of 5 degrees Celcius).
- In late-March you can start to plant-out tender vegetables.
- Fruiting crops like raspberries like lots of fertiliser – use bonemeal in spring on the raspberry and rhubarb patches. Also apply well-rotted manure.
- Keep autumn planted beds of onion & garlic weed-free.
- Prune gooseberries and red & white currants. Remove dead wood then spur-prune all sideshoots back to 1-3 buds from the base. Shorten branch tips by 1/4.
- Avoid direct-sowing into the soil too early. Many plants including brassicas germinate best in soil temperatures of 7 degrees C or more.
- Plant onion & shallot sets. Plant 10 cm (4 inches) apart in rows 30 cm (12 inches) apart. Leave tops just showing.
- Plant soft-neck garlic
- Sow lettuce, parsnip, turnip, beetroot, peas and beans outdoors.
- Direct sow turnip, carrot directly into pre-warmed soil.
- Sow parsnip outside in clusters of five seeds spaced 15 cm (6 inches) apart to ensure complete rows of this inconsistent-to-germinate plant. Top tip: salad rocket germinates quickly and can be grown as a catch crop among other plants such as parsnip. So start the parsnip in March and then sown rocket in the area in April.
- Fill the ‘hungry gap’ from mid-March to May by sowing quick-to-mature edibles – eg salad leaves, pea shoots, spinach, beetroot, spring onions, and herbs such as dill and coriander. Ideally, use a moveable cold frame.
- In mild areas early potatoes can be planted in late March.
- March is the time to plant rhubarb and asparagus.
- Tidy strawberry plants. Remove damaged or dead leaves, old runners & fruit.
- Prepare trenches for runner beans with well-rotted manure at their base.
Sow Indoors / Under Glass
- sow brassicas (eg brussell sprouts, sprouting broccoli, cabbage, cauliflower), celery, leek & celeriac indoors for planting out early summer.
- sow tomatoes, peppers & chillies indoors with a heated propagator.
Flower / Ornamental Garden
- Apply slug & snail protection around delicate perennials susceptible to damage.
- Deadhead spring bulbs as flowers fade to channel growth into the bulb for next year’s blooms.
- Divide snowdrops as they die back and replant divisions singly at the same depth as growing previously. Do this ‘in the green’ when flowers fade to spread clumps through the garden.
- Prune hydrangea by cutting back old flower heads to the first pair of strong buds. Cut a third of oldest stems back to their bases.
- Prune established bush and standard roses & feed as they come into growth.
- Complete pruning hybrid tea and floribunda roses.
- Apply rose fertiliser, mulch and manure to all roses after final pruning.
- Renovate overgrown honeysuckle by cutting back as low as 2 feet.
- Mulch borders with organic matter and kitchen compost, but keep away from direct contact with the bark of trees and shrubs, as this may encourage rot.
- Start to put supports up for perennials – lillies, gladioli, etc.
- Divide overcrowded clumps of herbaceous perennials (like day lilies) – do this at least every 4 years for optimal plant growth.
- sow sweet peas outdoors.
- sow hardy annuals such as poppies outdoors.
- Plant gladioli bulbs in milder areas (though planting can be delayed to April).
- March is the start of the main breeding season for garden birds. Birdsong intensifies.
- Ensure there’s clean water in the troughs for birds & wild things. Put a stone in the middle of your water tray and also a stick to aide escape if anything falls into the water.
- March is a good month to sow annual and perennial wildflower meadows.
- Avoid turning compost heaps until late March as they may be sheltering hibernating frogs, small mammals and insects.
- Buy & plant native pond plants such as marsh marigold (caltha palustris) and water mint (mentha aquatica).