Start planting your winter and spring flower garden as well as cool season salad crops, writes Alice Spenser-Higgs
APRIL is always a month to look forward to in the garden because the heat, rain and pests are no longer so ferocious. In the flower garden summer annuals can be removed as they fade and winter or spring flowering annuals planted in their place.
Fork some compost into the top layer of the soil before planting a new crop.
Iceland poppies and primulas are long-season crops and should go in first says Marlaen Straathof, of Kirchhoff Seeds.
Poppies like full sun in winter and they should be planted en masse for the best effect.
Landscaper Karen Gardelli plants Champagne Bubbles (yellow, orange, pink, cream) among the roses to provide colour when the roses are bare sticks after pruning. For extra oomph she mixes pansies and violas in shades of yellow, blue and white among the poppies. They all flower well into October and provide colour around the base of budding and flowering roses. A new pansy worth considering is the Fizzy Fruit Salad Mix, which has ruffled petal edges and is an ideal bedding pansy. The mix consists of blueberry, grape, lemonberry and raspberry shades.
If planting poppies now, leave space for the pansies, as seedlings only become available towards the end of April or May.
Petunias can also be planted towards the end of April when the likelihood of rain has passed and if they receive enough sun will flower until the summer rains.
This month is the last chance to sow sweet peas. However, Namaqualand daisies can still be sown until May. Other flowers that grow easily from seed are the fragrant Virginian stocks, linaria, mesembryanthemums, ursinia, and alyssum.
Sparaxis seed can also be sown directly into the flowerbed. It forms bulbs and if left in place will flower again the following year.
The cooler sunny days are ideal for sowing and growing salad and leafy veggies such as lettuce, Swiss chard, spinach, oriental vegetables (mizuna, pak choi, tatsoi and mustard leaves), rocket and flat-leaf parsley. Cabbage can also be sown, but the sowing window only extends to the end of April or up to the middle of May. After that the first frost can be expected.
Swiss chard, spinach and cabbage can be sown directly into the soil. The final spacing of plants should be about 20cm apart.
Because Swiss chard and spinach grow slower during winter it is a good idea to sow what you need before mid-May to make sure you have enough planted to keep you going through the cooler months. The normal rate of succession sowing is every three to four weeks, but this can be reduced to every two weeks.
When harvesting, cut two or three of the largest leaves or leave the outer ring of leaves and cut the second level — but don’t cut into the crown. Cutting off all the leaves at once puts a huge strain on the plant. Good yields come from harvesting continually and regular feeding with a liquid fertiliser, like Margaret Roberts Organic Supercharger.
In winter, lettuce grows best in full sun or with plenty of morning sun. Lettuce seed is so fine that it is better, and less wasteful, to sow it in seed trays and only transplant the lettuce when it is 10cm high or big enough to handle. Plants should be spaced at least 30cm apart so that air can circulate freely and the leaves are able to dry off quickly after watering.
Broccoli, cabbage, cauliflower and Brussels sprouts should have all been sown, but you will also find seedlings of these in garden centres. They need to grow fast during April and May to be well established before winter.
Give newly planted seedlings a boost by feeding weekly with a diluted foliar feed, a granular 5:1:5 fertiliser (once a month or half doses twice a month) or compost tea. Make sure the soil doesn’t dry out by keeping a thick layer of mulch on the bed.
Other vegetables that can be sown in April are carrots, beetroot, broad beans and radishes.
One way of making peace with pulling out annuals that still have a few flowers on them is to start a new compost heap. There is plenty of other material from the garden that can also go on the heap — fallen leaves, grass clippings, herb prunings and vegetables that have come to the end of their harvest.
Make a base of larger branches or sticks. This helps with the drainage and aeration. A balance of nitrogen and carbon is achieved by alternating layers of green and dry plant material. If there are not enough fallen leaves, tear newspaper into strips or use egg cartons to provide the carbon layer. Keep building the heap until it is about 1,5m high. To activate it, include comfrey, fennel or borage leaves with the green material, or sprinkle compost activator over alternate layers.
Some gardeners turn the compost heap every three weeks while others leave it in place to do its job slowly. Turning aerates the pile and can speed decomposition.
A new pansy, Fizzy Fruit Salad Mix, complements most colour schemes.