Calendar of Garden Work for May

MAY is the first really rewarding month of the year when early salad crops, asparagus, early peas and flowers for the house can be expected. The general routine work of April — hoeing, sowing, thinning and planting — must still be continued.


As herbaceous perennials will be growing quickly, stake them before the foliage grows too heavy or too difficult to handle without breaking. Use strong, twiggy stakes and push them down firmly in a ring round each plant, sloping them slightly outward. The plants will grow through the twigs and soon hide them.

Lift spring bulbs and heel them in, in some corner of the garden. Clear the beds and prepare them for the summer bedding display.

Keep the border lightly forked, and mulch paeonies and delphiniums with well-rotted compost.

Half-hardy annuals such as nasturtiums can be sown in the open.

The seedlings of annuals sown in April will require thinning. Stake them with rather thin twiggy stakes so that the plants can grow through them and hide their supports.

The old forget-me-nots, double daisies (Bellis perennis) and polyanthus can be divided now and set apart in a nursery border for use in the following year’s spring display.

Continue to prune early-flowering shrubs after they finish flowering. Cut back, if necessary, branches of evergreen shrubs to make them shapely.

Feed roses and lilies with liquid fertilizer.

This is an especially good month to apply selective weedkillers.

Seeds of wallflowers, forget-me-nots, Siberian wallflowers, and biennials such as honesty and Canterbury bells can be sown in rows for flowering next year.

Pelargoniums (geraniums) may be planted in tubs or boxes outside during the last week of the month. Window-boxes can be prepared for the summer display. They will need careful and regular watering from now on.

Watch out for aphids on roses and spray against them with malathion as soon as they are noticed. They increase quickly in dry periods.

Start a new compost heap now that more fresh material is becoming avail Continue to mow the lawn at regular intervals, taking the cutting blades a little closer to the sward.

Remove dead flower heads from the rock garden plants that have faded.


Continue with seasonal sowings to meet individual requirements. Keep hoeing between rows of seedlings, and thin out when necessary. In some years a period of drought may occur towards the end of the month, and the vegetable garden will therefore benefit from some extensive overhead watering. Peas, especially, should be kept growing and not be allowed to suffer the effects of drought.

Plant out Brussels sprouts, summer cabbage and cauliflower seedlings that have been raised under glass and hardened off. Puddle them in, especially in dry weather, and keep a sharp look-out for cabbage root fly and the turnip flea beetle.

Sow runner beans and dwarf french beans when the danger of frost is over. As a precaution against frost damage, give cloche protection at night.

Sow seeds of maincrop beet and the last batch of summer spinach.

In mild districts sweet corn can be sown out-of-doors at the end of the month.

About the middle of the month pinch out the tops of broad beans.

If not already done, prepare celery trenches, ready for putting out the plants in June.

At the end of the month, plant out ridge cucumbers from a sowing made under glass last month.

Sow seeds of late winter cauliflower and New Zealand spinach outdoors by about the middle of the month.

If not already done, prepare the ground for planting out tomatoes as soon as they have been hardened off.


Spread strips of black polythene or clean straw along the rows of strawberries to act as a mulch, suppress weeds, and keep the berries clean and free from slugs. Spray the plants with Karathane against mildew, then cover the bed with netting to protect the fruit from birds.

Thin out shoots of raspberries, leaving six or seven canes to each plant. Mulch both raspberries and black currants with clean straw.

Suckers formed on fruit trees and bushes should be removed from the base as soon as they appear.

Erect cages or netting over soft fruit to protect it from birds. Pick strawberries and gooseberries as they are ready.

Keep weeds under control.

In the latter half of the month, thin out the fruits on peaches and nectarines.


The early tomatoes in pots, rings or borders will need pinching and tying up. February-sown tomatoes may now be put into final pots or rings. Give full ventilation during the day and spray the outside of the greenhouse glass with whitewash. Keep the house dampened down during the day to prevent dry heat.

All seedlings and rooted cuttings may be cleared from the house to make room for melons or cucumbers.

Prick off seedlings of primulas sown last month and pot them into 3-in. pots.

Harden off rooted cuttings of chrysanthemums and dahlias for planting out later in the month.

Take cuttings of alpine plants and insert them in a sandy compost round the edge of small pots. Cover each pot with a polythene bag, first putting a couple of wooden labels or sticks in the pot to prevent the bag from touching the leaves of the cuttings. Slip on a rubber band to exclude air until the roots have formed. Turn the bag inside out each clay.

As bunches of grapes develop, the berries need thinning to give good shape to the bunches and to ensure even development of the fruits. If necessary hold each bunch with a short, forked stick and nip out the berries with long-bladed scissors, starting at the bottom of the bunch and finishing at the shoulder.

Harden off sweet corn for planting out later in the month.

Move tuberous begonias into 6-in. pots.

Mulch peach trees with well-rotted manure and train in young shoots.

Move late-flowering chrysanthemums at the end of the month into the pots in which they are to flower.

Top dress lilies in pots.

By the middle of the month move tomato plants destined for outdoors to a cold frame to harden off.

06. September 2013 by admin
Categories: Garden Calendar, Gardening History, Plant Biology | Tags: , , , , , , , , , , , , , , , | Comments Off on Calendar of Garden Work for May


Get the Facebook Likebox Slider Pro for WordPress