Early May
Keep all newly planted items well watered. This includes ones planted last autumn.
Sow seeds of herbaceous plants.
Sow or turf new lawns and keep mowing established ones – but not too low.
Treat difficult lawn weeds e.g. clovers, black medic with Weedol Lawn Weedkiller, it has the right ingredients for these weeds.
Hang up a codling moth trap in your apple tree, or a plum moth one in your plum tree, to reduce the number of maggoty fruit. There is also now a trap readily available for catching box tree moths which are now quite widespread in our area.
Plant out cabbage, cauliflower and other brassicas but take precautions against root fly.
Keep on top of pest and disease outbreaks, as well as controlling weeds.
Don’t forget your houseplants, feed and water them regularly.
Control algae and blanketweed in ponds.
Mid May
Sow suitable varieties of pansies to flower from autumn throughout the winter.
Sow biennials for flowering next spring onwards e.g. wallflowers, myosotis, sweet williams, foxgloves and honesty.
Plant out chrysanthemums for flowering in borders or for cutting.
Plant out summer bedding plants when frost risk is minimal.
Tie in wallshrubs and climbers to their supports try to train them at 45 degrees or horizontally to encourage flowering.
Trim over aubretia and arabis after flowering to keep them neat.
Prune wall trained pyracantha and chaenomeles after flowering.
Keep strawberry fruits off the soil using straw or mats.
Cut down spring flowering perennials – e.g. pulmonarias and doronicums after
flowering to produce a neat mound of new foliage. Untrimmed plants often become mildewed.
Sow swedes, beetroot, carrots, parsnips, French and runner beans outdoors.
Plant out sweet corn in blocks, rather than a long row, as they are wind pollinated.
Take cuttings from dahlias and chrysanthemums for flowering later in summer.
Plant tomatoes, peppers, aubergines, cucumbers etc in a cold greenhouse or outdoors if in sheltered site.
Make up summer flowering hanging baskets and containers.
Late May
Brighten up your patio with some spectacular frost tender container plants, like brugmansia.
Prune clematis montana straight after flowering, if they are getting out of bounds.
Plant out leeks, marrows, courgettes and melon plants.
Enjoy more herbs by sowing Basil, Corriander and Parsley every fortnight.
Spinach often runs to seed if sown after mid May – so sow leaf beet instead.
Sow some half-hardy annuals for use as winter pot plants e.g. calceolarias, schizanthus and cinnerarias.
Sow ornamental cabbage and kale for winter colour in tubs and borders. Beware of houseplants getting scorched on sunny windowsills.
Listen to the weather forecast in case of any nasty late frosts.