Top Jobs for May

1. Collect rainwater for irrigation.

2. Hoe regularly between rows on hot days to make sure the weeds dry up and die.

3. Open greenhouse vents and doors on warm days.

4. Watch out for viburnum beetle and lily beetle grubs.

5. Mulching around the base of your plants will help them to retain moisture around the roots.

6. Keep pots and hanging baskets well watered using collected rainwater wherever possible.  



• Plant summer bedding plants at the end of the month.

• Finish sowing hardy annuals: the later they are sown, the later they will flower.

• Put support frames into herbaceous borders to support plants with a droopy habit i.e., Lupins. •

Dig up, divide and replant polyanthus after they have flowered, discard any with disease.

• Start to harden off bedding plants by putting them out for the day and back in for the night.

• Protect susceptible plants from slugs. • Clear out spring bedding from beds and borders when it fades, and fork in fertiliser.

• Plant hanging baskets and put them in the greenhouse until the risk of frost is gone.

• Watch out for pest and disease on all plants.

• Deadhead spring bulbs (but do not cut the foliage back yet).

• Ensure newly planted plants are kept watered in dry spells.

• Prune spring-flowering shrubs to prevent them from becoming overgrown.  



• Mulch around Strawberries to prevent the fruit being spoiled, use straw or black polythene.

• Destroy any leaves of Peach and Nectarine which show signs of leaf curl.

• Spray a systemic fungicide on Gooseberries if mildew is a problem.

• Water newly planted fruit trees and bushes in dry spells.

• Harvest any early Rhubarb.



 • It is possible to plant out Brassicas (cauliflower/cabbage) if they have been grown in a greenhouse. Remember to use a Brassica collar to keep cabbage root fly away

• Most vegetable crops can be sown but delay if the soil is cold and wet

• Earth up early crop potatoes

• Weed between any vegetable crops that are growing

• Harvest any Asparagus spears that are showing



• Apply a weedkiller and fertiliser combination

• Seed new lawns and cover to keep birds away

• Mow lawns once a week if needed. Avoid cutting if there is frost on the grass

• It is now a suitable time to spot treat lawns if no general lawn weedkiller is used

• Lay new turf and keep well watered if a dry spell ensues  


Greenhouse, Sheds and Houseplants

  • Tie in the lengthening growths of Vines

• Ventilate well and damp down on sunny days as long as seed are not being raised

• Continue pricking out half hardy and tender seedlings

• In a heated greenhouse remove side shoots from tomatoes, but not bush varieties

• Pinch outside shoots of melons and cucumbers when two side shoots have been formed

• Watch for pests and treat immediately using either a chemical spray or a biological control

• Ensure heating is still available in case of a cold night  


Trees, shrubs, climbers and hedges

• Prune spring-flowering shrubs to prevent them from becoming overgrown.

• Take softwood cuttings of deciduous shrubs such as Forsythia, Fuchsia and Hydrangea.

• Prune out any frost damage on evergreen shrubs.

• Cut back tender shrubs such as Penstemon and Fuchsia after the danger of frost has past.

• Trim evergreen hedges to keep them neat. Evergreens such as Viburnum tinus can also still be trimmed this month.

• Prune spring-flowering shrubs such as Berberis, Choisya and Ribes after they have finished flowering.

• Prune overcrowded or dead stems of Clematis montana once it has finished flowering – don’t worry it will take even hard pruning very well.

• Late spring is a good time to coppice or pollard (cut back hard) Eucalyptus.

• Tie in climbing and rambling roses as near to horizontal as possible to restrict sap flow and result in more flowers.

• Remove any reverted green shoots on variegated (leaves with two colours) evergreens, to prevent them reverting to a single colour.

• Trim hedges (check for nesting birds first).  


Soils, Mulching and Weed control

• Mulch away while you can still see what you are doing and before the herbaceous growth really takes off. Use your own garden compost or leaf mould, well rotted manure, the contents of out-of-date grow bags or ready-made soil conditioner.

• Now the soil is warming up and things are starting to grow, add general purpose fertiliser before covering with mulch especially in borders, the fruit and vegetable patch and containers. If you have already mulched, draw it back (if possible), tease the soil a little, add fertiliser and replace the mulch.

• Carry on removing moss and weeds from paths, terraces and drives and keep an eye out for pests around the garden. Try to keep the use of chemical controls to a minimum - they may kill off pests, but they also kill off the beneficial insects that prey on them such as ladybirds and hoverfly larvae.



• Plant up new aquatic baskets with Water Lilies and oxygenating plants

• Feed fish if they are near the surface

• Keep pumps and filters running constantly


Plants which are at their best in May

Aquilegia (Granny's Bonnet)

Syringa vulgaris cultivars (Lilac)

Ornamental Cherries Crataegus (Hawthorn)

Clematis Macropetela (Clematis)

Meconopsis betonicifolia (Himalayan Blue Poppy)

Centaurea Montana (Perennial Cornflower)

Berberis stenophylla (Barberry)

Dodecatheon Meadia (Shooting Stars)

Primula Veris (Cowslip)

Chimonanthus Praecox (Winter Sweet)

Salix Caprea Kilmarnock (Kilmarnock Willow)

Daphne Mezereum

Forsythia (Golden Bells)