Last year the spring was so mild that gardeners were planting geraniums and bedding plants in April and they were lucky that the frosts, which usually come at the beginning of May, did not happen. It is much safer to plant our tender plants later in May and to press on with jobs which should be done this month. Hanging baskets, tubs and containers can be planted up in the greenhouse so that they can get well established before putting outside. Add a little SwellGel to help conserve moisture. If established shrubs are to be moved in the garden, this must be done without delay and bare root hedging plants and raspberry canes must be planted before the sap rises. Now is the time to lift and divide herbaceous perennials and to plant new ones. Taller growing plants will certainly need to be staked or supported in some way. Put down mulches on garden beds to keep down weeds and conserve moisture. Make sure that as much rainwater as possible is collected. Rhododendrons, heathers and plants such as blueberries do not like tap water and water from the water butt is useful for these.Many vegetables can be sown now and brassica seedlings, onions and asparagus crowns can be planted. Carry on planting potatoes; and early potatoes planted last month will probably need earthing up later this month. Sow under glass tender vegetables such as tomatoes, peppers, courgettes, marrows, cucumbers and runner beans. Thin out the carrots, watch out for slugs and keep on top of the hoeing and weeding. This is the month to get to work on the lawns, putting on fertilizer and weed killer and keeping up with the mowing. It is better not to cut grass too short and to mow every few days in the spring.
Bulbs such as gladioli and lilies, and tubers such as dahlias and cannas, must be planted as soon as possible. Shrubs which have flowered, such as forsythia, will need to be pruned and camellias may be pruned once flowering is over. Now is a good time to trim lavenders before they start to flower. Sunflowers can be sown now, preferably under glass. Regularly spray roses and feed with Toprose fertilizer which is a good feed for many shrubs and climbers too. Feed strawberry plants with a high-potash fertilizer such as Tomorite. Ornamental prunus such as flowering cherries should be pruned as soon as they have flowered.
The Capel Manor Spring Show is from 11-13 April and the Hertfordshire Garden Show at Knebworth is on 4-5 May. Dont forget to order tickets for the Chelsea Flower Show which is from 20-24 May (0870 842 2217) and the Malvern Spring Gardening Show from 8-11 May (call 01684 584924).
Terry Simmonds