Gardening Jobs for May

With the evenings even longer, the days warmer May is when the real gardening begins, yes there is lots to do, but please remember to take time to stop, to look and to enjoy the beauty in gardens in May.

If you are looking for a few gardening jobs for the month, here are “just a few” things to keep you busy.

I wish you Happy Gardening!   


Please remember to keep pots watered, when a plant is in the ground it can usually find moisture, but when in a pot or container the soil dry’s not only from the surface but also from the sides of the pot.

Plant out dahlia tubers and cannas after all risk of frost has passed, possibly at the end of the month.

Continue sowing annuals, such as California poppies, into gaps in borders for colour from August into autumn

Tie in climbers.

Apply liquid feed to tulips, daffodils, and other spring bulbs to encourage a good display next year

Remove faded spring bedding, such as wallflowers and forget-me-nots, once faded and add to your compost bin

Harden off tender plants raised indoors, but bring them back in at night to protect from late frosts

Pinch out the shoot tips of bedding plants and young annuals to encourage bushier growth

There's no shortage of seeds to sow in the May Garden, with many now being able to be sown straight into the soil outside, sunflowers, cornflowers, zinnias, nasturtiums, nigella, poppies and wildflower mixes can all be sown directly into beds, borders or outdoor containers.

In trays and pots you can start growing biennials and perennials, such as foxgloves, wallflowers, delphiniums, lupins, and primroses in the greenhouse or on the windowsill to flower next year and years to come.

In May there’s usually a frost or two still to come. If you’ve planted tender bedding, such as petunias, heliotrope, fuchsias, or begonias, it’s best to cover them on clear nights. Sheets of newspaper, or horticultural fleece, will keep them snug if temperatures dip.

Feeding now will pay dividends later on, but you must use a slow-release fertiliser containing potash, to encourage more flowers. Vitax Q4 is excellent and this general fertiliser can also be applied to roses, herbaceous plants, and fruit. Avoid adding nitrogen-rich plant food: it produces too much leaf.

Vegetables will also respond to enriched soil. The easiest soil enhancer is well-rotted garden compost, so it’s really worth making your own if you’re able to. You can also use well-rotted manure, although spreading it in early spring can be backbreaking. However, you can also buy bagged manure from garden centres. The best way to incorporate organic matter into a vegetable bed is to put some at the base of the planting hole. Squashes and courgettes benefit hugely from sitting above organic material because it aerates and warms the soil.

Do the Chelsea chop: Cutting the stems of flowering herbaceous perennials such as sedums and asters will keep plants smaller and encourage more flowers. This should not be done on flowers which flower only once, or flowers which are intended to be tall and striking.

Keep an eye on slugs, especially when its been raining. Indeed, during a rain shower is the perfect time to get outside.

Weeding: Five minutes here and there (rather than a whole afternoon) with a hand or long hoe saves fingers and backs.

As well as weeds you will also find self-seeding plants taking off in May. Thin out gluts of self-seeders such as poppies and fennel leaving the strongest where you want them to flower, remembering that its best to keep them from flowering too close to the edges of beds.

In the flower boarder any frost-damaged leaves should be pruned back to the next healthy bud or side shoot. Frost damaged plants often recover so don’t immediately pull them up but wait until summer, giving them time to regrow. If there’s no sign by mid-summer you can pull them up.

Get rid of any brown or faded material in the borders. Certain plants have already finished flowering and they can be tidied. Deadhead all, or most, aquilegias, because these self-seed far too enthusiastically.

Prune forsythia after flowering If you don’t do this every year, they quickly get unmanageable and flower less well. Using sharp loppers and secateurs cut a quarter of the old growth to the base. Also remove diseased, dead, dying, and wispy stems cutting them to the ground. Finally prune stems that have just flowered to two buds above the previous year’s growth.

Start hardening off seedlings of beans, tomatoes and other plants sown indoors or under glass. Allow a couple of weeks for the process gradually acclimatizing the plants. French beans can be particularly delicate so take care not to expose them suddenly to strong winds or rain or scorching midday sun.

Make a bean wigwam using canes or hazel stems to make a support for growing beans. Either tie the tops together to form a wigwam or else arrange the supports in long Xs that cross either halfway up or close to the top. Sow a couple of beans to each cane and a few at the ends of the row as replacements for any that don’t come up. Beans are greedy plants so they’ll enjoy being grown above a trench filled with rotted manure or kitchen compost (even part rotted will do). Cover the trench with soil and then plant the beans. Once the beans are up, make sure that the slugs cannot get to the growing tips because they’ll destroy the plant.

Thin out vegetable seedlings already planted allowing space for individual plants to flourish. Wash and use thinning of lettuces and beet tops in salads.

Check strawberry flowers for frost damage in colder areas, net them against birds and lay down straw under the plants to protect them from rain.

Liquid feed young plants regularly to keep them growing strongly

Sow half-hardy annual seeds outdoors where they are to flower

Tidy up Clematis Montana once it has finished flowering

Clear pots and containers to make way for summer displays

Prune spring-flowering shrubs once they have finished flowering

Plant out tender vegetables once the frosts have passed

Tie in early tomatoes and keep liquid feeding them

Put straw under strawberries to prevent young fruit rotting

Sow sweetcorn in blocks to aid pollination and sow root vegetables

Earth up potatoes once growth reaches about 25cm (1”)

Start planting out summer bedding plants towards the end of this month in warmer parts of the country. 

Look after your finished spring bulbs for next year. Once they’ve gone over, resist the temptation to cut back the foliage. Instead, let it die and break down on its own and add liquid fertilizer all around the clumps. This will give you an even better display next spring.

Harden off half-hardy plants by leaving them outside during the day and bringing them back under cover at night for 7 to 10 days before planting outdoors.

Continue dividing herbaceous border perrinals to improve vigour and create new plants.

Divide established clumps of hostas as they come into growth.

Towards the end of the month, keep an eye out for powdery mildew on flowering shrubs and flowers, like rhododendrons. Treat with fungicide to prevent further spread.

Lift forget-me-nots to prevent heavy self-seeding and reduce spreading.

Prune penstemons now — cut all the old shoots back to the base, providing there is new growth at the bottom of the plant. If there are no new shoots at the base, cut just above the lowest set of leaves.

Lightly cut back & tidy up late-flowering honeysuckle. Leave any big pruning jobs until winter.

Take cuttings of tender perennials, such as fuchsia and pelargoniums (tender geraniums). The new shoots of hardy perennials can also be used for cuttings.

Take softwood cuttings of shrubby herbs. 

Tie in rambling and climbing roses. Laying the stems horizontally will help to produce more flowers.

Tie in sweet pea plants with sweet pea support rings to encourage them to climb.

Prune spring-flowering shrubs after flowering.

Cut back flowered shoots of choisya to promote a second flush of flowers in autumn.

Trim lavender plants, cutting off old flower heads and about 2.5 cm (1 inch) of the current year's growth.

Feed and water container plants.

Top-dress permanent pot plants to refresh the compost.

Supplement container plants with balanced liquid feed every 2-4 weeks to promote healthy growth.

Closely inspect plants for pests and diseases — early prevention is much easier than curing an infestation.

Look out for signs of blackspot on roses. If discovered, treat it with a systemic fungicide.

Continue to weed beds and borders. This reduces your plants’ competition for water and nutrients.

Lift and divide overcrowded clumps of daffodils and other spring-flowering bulbs.


The above is written by Rog Leppard of English Cottage Chic Gardening. I am professional gardener and gardening writer based in North Baddesley, Romsey, Hampshire.