aPRIL GARDENING JOBS
Sowing and Growing
You can start to direct sow hardy annuals as the ground reaches 6C. The same goes for salads, you can start to sow salad, beetroot and annual herbs, such as dill and rocket.
Always continue to sow seed of half-hardy annuals under cover. Sow in small pots rather than trays to save space . it’s also a good idea to harden off seedlings that have been started off indoors 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.
Never handle seedlings by the stem when pricking out. To avoid damage, gently grasp the first set of primary leaves. Remember to get as much root as you can by pushing your dibber (or use a rigid plant label) right down to the base of the seed tray and lifting from there.
If you are turfing, this is the perfect time to do so. If the weather is dry you may need to water to prevent curling at the edges. Feed established lawns with a slow-release organic fertiliser high in nitrogen to get things off to a good start.
Sow perennials – these could include hollyhocks, delphiniums, Linaria purpurea 'Canon Went' and echinaceas. Fill a seed tray with peat-free compost and dampen with water. Sow seeds spaced at least an inch apart in a grid across the compost surface. Then scatter (or sieve) a fine covering of compost over the seeds. You don't need to water again immediately. Place in a light, cool spot, eg a window ledge or, if you have one, in a propagator in a cold frame, greenhouse or polytunnel with basal heat.
Later in the month, thin out hardy annuals sown in drifts or rows to allow plants to reach optimum size.
Pot cuttings of tender perennials, eg pelargoniums, arctotis, verbenas, penstemons and argyranthemums, taken late last summer or autumn. They'll be well rooted now and will benefit from some fresh compost and more space for root formation before planting in their summer position.
Bulbs and Tubers
If you have received your dahlia tubers, now is the time to get them potted up. Follow our instructions carefully and you will have wonderful flowers to cut all through the summer months.
Finish planting summer-flowering bulbs. This includes eucomis, crinums and the deliciously scented cousin of the gladiolus – acidanthera. Plant them in pots or in the ground.
Plant lily bulbs straight into the ground. Give them plenty of room and, on heavy soil, add grit for drainage to their planting hole. Most varieties thrive with their bulbs in some shade and tops emerging into full sun.
Any indoor forced bulbs – hyacinths or Narcissi 'Avalanche' and 'Cragford' – can be planted into the garden when they've finished flowering.
PERENNIALS, SHRUBS AND TREES
Pruning and Tidying
Keep on top of the tiny annual weeds emerging with a hoe. Only hoe on dry days – this way any weeds that you hoe will die off and wilt quickly. Run the blade back and forth over the soil to break it up and cut down any of the newly sprouting weeds. You can save so much back-breaking work later on if you do this every other day for a few minutes.
Perennials such as bindweed will start to appear big-time now. Dig them out, tracing the roots as far as you can, or train the tip up a bamboo cane and then treat with a suitable weedkiller.
Cut back the last of the perennials and lightly fork over the soil carefully without damaging emerging shoots.
To keep your roses growing healthily and for the best flowers this summer, make sure that your climbing roses are well tied down. Bend over any upright stems to encourage more flowers – you will normally only get flowers at the top of an upright, but if you bend them you will get more flowers along the stem. Tie them in so they are lying horizontally. This will also create a thicker screen, if you are using the rose as cover or to beautify a not-so-pretty wall or fence.
Lavender plants need cutting back now to prevent them from looking sparse. Give the plant a short back and sides with secateurs to snip off old flower stems and shoot tips. Don't prune hard into old wood, as this will prevent new growth. While you are pruning, shape the plants into domes and remove any leggy or unwanted stems. Give the plants a weekly liquid feed during the summer, to encourage growth.
Tidy up tussock-forming grasses with a shaping haircut.
Now is also the time to divide and replant species such as Stipa gigantea, which struggle when newly planted in the wet and cold of winter.
Last chance to cut back shrubs, especially those grown for colourful winter stems (eg dogwood or willow). Cut back to buds about knee height, then feed and mulch. Also cut back winter flowering jasmine when flowering has finished. Prune back to within 5cm of the old wood to promote branching.
The late summer flowering Viticella-type clematis need pruning now. Cut them back to about knee height, above a clutch of growth buds.
Plant new evergreen trees and shrubs.
With the soil warming up, it is also a good time to move evergreen trees or shrubs. Their roots will then grow off fast, but you must keep them well watered until autumn.
THE VEGETABLE GARDEN
Try direct sowing some new salad leaves, carrots, peas, beetroot, spinach and chard.
Sow some quick growing half-hardy annuals, like pumpkins, squash, sweetcorn, basil and French beans.
Plant Maincrop potatoes.
Plant tomatoes and cucumbers (under cover).
Keep on top of thinning seedlings.
Rotavate the vegetable garden. Get ready for a mass sowing of hardy annual veg, such as spinach, carrots, beetroot, lettuce and radish. On heavy soil, integrate plenty of grit and organic matter. On freely drained soil, only muck and/or compost need to go in.
Plant out onions, shallots and garlic.
Pot on tomatoes. It’s tempting to move tomatoes from a module or seed tray straight into their final, large planting pot, but this slows growth. Tomatoes like to feel contained and cosy; their roots can’t cope with a large volume of compost and tend to rot. Pot them only one size up and add a cane at their side to support them as they grow.
Plant asparagus crowns.
Salad and herbs
If you want to get going with some salad, sow now undercover or in gutters in your greenhouse or conservatory. Eg corn salad, rainbow chard, mizuna, rocket, winter purslane, mustard and plenty of lettuces.
Direct sow chervil, chives and coriander or sow dill, fennel and French sorrel under cover.
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 seal.
Repot your citrus in fresh citrus-specific compost. If you can’t find this, ericaceous is the next best thing.
Top dress blueberries grown in pots with ericaceous compost. It’s important to have two different varieties of blueberries to get good production – they will fruit without, but you’ll get a paltry quantity.
All soft fruits, eg 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.