It’s a good idea to keep a close eye on the weather during April. Frosts are still common, and many plants and flowers may need protection in the form of fleece or cloches. Hopefully, the ground will not be too wet and so now is a good time to finish off digging over your plot in preparation for all the vegetables you are going to grow. As the weather gets warmer, the weeds will grow in earnest. Regular weeding, before they become established, is important.
Start an asparagus bed
Early April is not too late to start an asparagus bed. Make sure the ground is prepared ready for the arrival of the asparagus crowns as you will need to plant them shortly after they arrive. The crowns must not be allowed to dry out. For this reason, don’t buy them from a garden centre where they have been kept on a shelf for several weeks.
Earth up first early potatoes and plant out second early and maincrop varieties
Protect first early potato shoots against frost by earthing up as they break through the soil. Second earlies and maincrop seed potatoes can now be planted. Chitting the seed potatoes beforehand may improve yields, but is not essential.
Keep on top of weeding
It is much easier to deal with weeds whilst they are small. Pick them out by hand or use a trowel or hoe. Doing this regularly will mean a weed free plot, and nowhere for pests (especially slugs) to hide.
Put up bean supports
Put in place wigwams or rows of canes ready for your runner and climbing french beans. As the ground is soft, it will be easy to push the canes into the soil.
Sow vegetable seed outdoors
Many seeds won’t germinate until the soil temperature has reached about 7ºC, but if the weather has been warm you can start sowing carrots, broad beans, parsnips, spinach, beetroot, peas, mangetout, lettuce, radish, scorzonera, swiss chard, rocket, runner beans, salsify, sorrel, sprouting broccoli, swede, and turnips.
Sow vegetable seed indoors in trays or pots
Start sowing indoors, or in a greenhouse or coldframe, celeriac, kale, parsley, leeks, brussel sprouts, summer cabbage, cauliflower, lemon grass, comfrey, calabrese, peas, mangetout, squash and pumpkins. Towards the end of the month start sowing sweetcorn, cucumber, courgette, french and runner beans, ready for planting out mid May. If you have a greenhouse that they can grow in then you are not too late to start chillies.
Plant onion and shallot sets
If you have space, now is the time to plant onion sets. White onions are relatively cheap in the shops but red onions and shallots are much more expensive, so it’s worth thinking about growing these.
Harden off plants
Seedlings that have been started indoors but are to be grown outside can be hardened off on warm still days. Place them outside during the day, but take them in again late afternoon, and do this for about a week or so. This way they will get used to the cooler conditions before being planted outside.
Protect plants from frost
If a frost has been forecast, protect plants using horticultural fleece or cloches.
Divide herbaceous herbs
Herbaceous herbs, such as chive, oregano, mint and tarragon can be dug up and divided in early April, just before proper growth begins. Divide the root clump, re-plant and water well.
Clean up your strawberry beds or pots
Remove any dead or damaged leaves and old runners from the plants. If the plants are getting older, thin out the smaller crowns leaving 3 to 4 crowns per plant. Apply a fresh layer of straw if using as a mulch.
Apply a mulch to soft fruits
All soft fruits, such as strawberries, raspberries, redcurrants, blackcurrants, and gooseberries will benefit from a mulch. Garden compost, leaf mould, organic manure, straw, hay and spent mushroom compost can all be used. Hay is more beneficial than straw as it breaks down more easily and releases more nutrients into the soil.
Apply an acidic mulch to blueberries and cranberries
These are acid loving plants, so mulch with an 8cm (3in) layer of acidic material such as bark or old pine needles (kept from your christmas tree!).
Prune stone fruit trees
To avoid risk of infection, stone fruits, such as plum, cherry, peach, nectarine and apricot should only be pruned during the growing season. Prune late April, when the plants are in leaf and after flowering. Immediately seal all cuts greater than 1cm (½in) with wound paint.
Sit and relax with the sun on your back
Don’t forget to take a few moments to sit in the sun, listen to the birds, and admire any colour you have in the garden.