Plant hardy herbs like parsley, chives, lemon balm, sage and thyme for a supply of fresh herbs during late spring and summer. If you have large, established clumps, now is an ideal time to lift and divide them.
Remove any reverted green shoots on hardy, evergreen shrubs such as euonymus, eleagnus and all other variegated shrubs, to prevent the reversion taking over.
Mow lawns when necessary and when the weather allows, keep the blades relatively high for the first few cuts. If your lawn colour is pale green or yellowish, apply a lawn feed to encourage good, new, dark green growth.
Regularly check all plants growing in patio pots and containers. Keep them well watered, top up the pots with new multipurpose compost, and feed with a slow release fertilizer.
For a summer supply of new potatoes, early potatoes are best as they are usually harvested before potato blight or drought becomes a problem. Plant chitted seed potatoes now, either in the garden or large pots on the patio – keep them well-watered and fed, and they should be ready for harvesting in 13 weeks.
Check if any houseplants require repotting, including orchids, and replant using appropriate potting compost. Increase watering and feeding as daylight and temperature increases.
Watch out for any signs of slug damage on newly emerging seedlings and plants – organic slug pellets, slug traps and nematodes are available to help you control them.
Direct sow broad beans. Plant seeds 5cm (2″) deep into well prepared fertile soil at 23cms (9″) apart, and water well if required. Successional sowings will ensure a continuous supply and longer harvest. Try varieties such as Masterpiece Green Longpod, Medes and Witkiem.
Remove the dead flower heads from daffodils and tulips, apply a balanced fertilizer of liquid feed such as liquid seaweed, then let the foliage die back naturally. Daffodils that are overcrowded can be lifted, divided and replanted.
Sowing new lawns or over seeding sparse and dead patches in established lawns can be carried out when the weather allows. Special seed mixtures include those for shade, hard wearing, multipurpose and fine lawns.
Spray roses with a combined insecticide and fungicide such as Rose Clear Ultra, to kill and prevent pests such as green and black fly and diseases including blackspot, powdery mildew and rust.
Wall trained fruit trees in flower such as apricots, pears, peaches etc, should be protected from severe frosts with horticultural fleece. Cover only when frost is present and uncover when the weather allows, giving bees access to the flowers.
Plant gladioli corms in groups or rows, with the corms 10cm (4″) deep and the same distance apart. Many varieties and striking colours are available, including tall-growing, short-stemmed and hardy. They’ll provide excellent colour for your garden in late summer, and are ideal for cut flowers.
Dig out patches of coarse grass from lawns, fill the holes with sifted topsoil, then re-seed or re-turf. Water well during spells of dry weather.
Plant onion sets when the soil is sufficiently dry and warm. Pick the variety which is right for you:
Centurion is one of the earliest, Stur BC is good for late harvesting, Picko Bello works well for long storage, and Red Baron is excellent for salads.
Plant new pot grown trees, shrubs, perennials and roses. Always plant in well-prepared sites, add some slow release fertilizer, and keep them well-watered during hot, dry weather.
Tie in stems of climbing and rambling roses as near horizontal as possible – this will restrict sap flow, stimulating more side shoots, so more flowers will be produced. Feed with a rose food or general purpose fertilizer.
Plant out autumn sown sweet peas in well prepared soil. Prepare a wigwam support of canes for them to climb, using a light garden twine to guide them. You can also directly sow the seed at this time.
Sow carrot seeds 1.5cm (½”) deep into finely prepared soil. If you’ve been troubled with carrot fly, try varieties such as Flyaway or Resistafly, or put up a barrier of fleece 60cm (24″) high, attached to stakes, which will help thwart the fly.
Apply a combined lawn feed, weed and moss killer if required – always follow the manufacturer’s recommendations on application rates, timings and whether the product needs watering in. Never add the next two cuttings to the compost heap.
Plant lilies in the garden or patio pots. Dwarf, medium and tall growing varieties are available in a wonderful selection of colours, adding fragrance and colour to your garden.
There’s still time to plant out first early, second early and maincrop potatoes, as well as Jerusalem artichokes and asparagus crowns – the modern, all-male, named varieties are recommended, because male plants have fatter and more succulent spears.
Now is an ideal time to plant new evergreen shrubs and conifers in the ground or patio pots. Evergreens need to be kept well watered in dry spells – if you skimp on this, the plant can go brown, and some never recover.
Acid-loving plants such as rhododendrons, azaleas, camellias, pieris and blueberries will all benefit from an application of sequestered iron or an ericaceous fertilizer, to prevent the leaves yellowing and help encourage strong, healthy growth.
Keep on top of weeding now the weather is warming up. Weeds can be a problem in borders, lawns, and driveways, but you can control them by hoeing, chemical control, and applying a mulch of composted bark.
Check lawns for signs of weeds – you can dig out individual plants with an old kitchen knife or a daisy grubber. Alternatively, apply a lawn weed killer such as Resolva Lawn Weedkiller Extra.
Sow salad crops such as radish, lettuce and beetroot. Small sowings at three week intervals will give you a good succession of crops throughout the summer.
Prune early spring-flowering shrubs like forsythia, flowering currants and Japanese quince as soon as flowering is over. Pruning at this point will help to keep the plant neater and encourage a lot more flowers next year.
Check rhododendrons, camellias, hydrangeas, heucheras and primulas in the evenings for any signs of vine weevils. You will only find the adults, but the larvae will be eating the roots. Apply nematodes if you do find them.
Plant new perennials – a vast range is available now. Plant into well-prepared sites and keep them well-watered during dry spells.