Jobs for the month
As May arrives hopefully with it comes summer. Do however keep a watchful eye for late frosts protecting tender, frost-susceptible plants.
If you still have potatoes remaining to be planted, get them planted right away. Although it’s late, you should still expect a good crop.
Bedding and patio plants may be planted out, as frosts disappear towards the end of May. In order to get a good summer display, now is the time to plant up hanging baskets, window boxes and patio containers.
Hoe weeds frequently, especially in warm, dry weather. Hoe early in the day, using a sharp Dutch hoe for best results and allow the sun and wind to wilt the weeds during the heat of the day.
Greenhouse vents and doors should be opened on warm days.
If you haven’t already, feed trees, shrubs and hedging using a good proprietary tree and shrub fertiliser. Feed Rhododendrons and other ericaceous (lime-hating) with a specific ericaceous fertiliser.
Lawns that are growing rapidly will now benefit from weekly mowing.
Dahlias are an essential component and feature of colour in the late summer/autumn garden. Flowering from late June until the first frosts of late October, they may be planted during May from tubers or as plants usually available either in packs or pots. Many people give the tubers a head start by starting off indoors in a greenhouse or conservatory where the tubers are potted into moist compost and allowed to develop. When all frost is gone they maybe gradually hardened off and moved to their summer quarters.
Dahlias come in a huge array of colours, heights and flower formations. So diverse is their variety that they are grouped into specific groups and classifications: Single-flowered; Anemone-Flowered; Collarette; Water-Lily; Decorative; Ball; Pompon; Cactus; Semi-Cactus; Miscellaneous.
The dwarf bedding varieties are ideal for bedding or for patio containers. The taller varieties should be well and securely staked using strong, stout, robust stakes. Sheep netting may be pulled down securely over four posts allowing the plant to grow through the mesh. Move the mesh upwards as the plants develop in height. Protect against slugs at all times. Good rich soil, which has been well manured, is best for successful Dahlia displays. Keep weeds down by placing a heavy mulch of straw and water well during dry spells.
Liquid feeding with a seaweed-based liquid tomato fertiliser is recommended during the growing and flowering season. Spacing will depend on the variety: The dwarf bedding varieties are planted at 30 cm. apart whereas some of the larger growing varieties need 90cm between the plants. Packaging and labels accompanying the plants or tubers will usually have instructions on recommended planting distances.
Hanging Baskets and Window Boxes
Hanging Baskets and Window Boxes for summer displays may be planted up during May. Discard old compost from last year. Make sure chains are intact, replacing if not secure. Window boxes should have drainage holes drilled if not already in place. Add a slow-release fertiliser and water retention gel in the fresh compost.
Sunny Aspects: Geraniums; Petunias; Lobelia; Nemesias; Petunias; Surfinias.
Shaded Sites: Fuchsias; Begonias — trailing, non-stop, semperflorens; Nasturtiums.
The containers will benefit from being placed in the shelter and protection of a greenhouse until established. Feed weekly with a liquid Tomato fertiliser.
Tender vegetables maybe started under cover early this month for planting out at the end of May/early June when all risk of frost is over.
The following may be started in peat pots (7-10cm.)
• Sweet Corn.
• Runner Beans
• French Beans
• Climbing French Beans
• Outdoor Tomatoes
Sow/plant Broccoli for late winter/early spring maturity. Sow/plant cabbage for late autumn/winter maturity. Sow lettuce and salad leaves at regular successions. Sow/plant beetroot. Swedes and turnips may be sown this month. Sow peas for a late summer/early autumn crop.
Herbaceous Border/ Perennials
Ensure good stakes are in place for the taller perennials and that they are well and securely staked, especially Delphiniums, Lupins, Phlox etc.