Trees, Shrubs and Roses
There are still a couple of weeks left for planting root-balled evergreens, as most kinds will be coming into growth. Root-balled evergreens, and evergreens in pots, usually do very well when planted just as growth starts, because they root into the surrounding soil straightaway. Water young trees and shrubs, as necessary, until they are settled in and making active growth. The new growth on bush roses and repeat-flowering climbers should be sprayed against blackspot disease. Magnolias can be planted now in flower as the roots are active about the same time. These are all sold in pots nowadays but a small palnt could be moved now too.
Perennial flowers in pots can be planted at any time but it is practically too late for lifting and dividing perennials now, or at least only with lots of watering.Hardy annual flowers such as calendula and candytuft can be sown now and will flower in late summer. Dahlias and gladiolus can be planted directly outdoors from the middle of the month. It is late for sowing bedding flowers because they will flower very late ... buy plants in May.
Lawn feeding can be carried out now as grass growth begins, if not already done, particularly if the grass is yellow and thin. Mow regularly from now on. Use lawn mosskiller if there is heavy moss growth and feed the grass afterwards to boost it. Dead moss can be raked out but this is laboursome and not essential. Sow lawn seed as soon as conditions are suitable. Old, thin lawns can be over-sown with some fresh seed on the patchy areas in damp weather. A good shower of heavy rain helps to wash down the seeds and get them in contact with soil. Do not feed or use lawn weedkillers on wildflower areas.
Fruit, Vegetables and Herbs
Take advantage of any chance to sow vegetable seeds if the ground is right ... most kinds can be sown now. Control weed seedlings between vegetables as soon as they come up by hoeing on a bright dry breezy day. It is easier to get rid of weed seedlings when they are still small. Onion sets can be put in now. Potatoes can be planted. Apply some potash to fruit trees or a fruit fertilizer to improve growth and yield but not rich compost or manure when tends to promote soft growth and diseases.Spray apple and pear trees against scab diseases if the trees are of susceptible varieties and had scab last year.
Greenhouse and House Plants
Feed and water heavily all greenhouse plants, and repeat every week or two weeks to boost fast growth. Sow sweet corn and runner bean seeds in the next two weeks for planting out at the end of May. There is still time to sow seeds of sweet peppers and chilli peppers. Check all greenhouse plants for greenflies and other pests now. Plant out greenhouse tomato plants, purchased or home-grown.