Tips on what to do in the garden in May

May is one of the busiest months here at the nursery and in your garden. Everything is starting to grow well and the garden is really starting to come into life, unfortunately this means that weeds and grass are also coming on strongly, so there really is no time to relax.

Flower Beds, Borders and Pots

Now the soil is warming up and plants are starting to grow, add some general purpose fertiliser to your beds, borders and pots and then cover with mulch. If you have already mulched, draw it back (if possible), tease the soil a little, add fertiliser and replace the mulch.

Mulching now is advisable, whilst 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 Use your own garden compost or leaf mould, well-rotted manure or the contents of out-of-date grow bags.  Mulch is effectively a protective cover placed over the soil to retain moisture, provide nutrients, and suppress weed growth and seed germination.

Continue to plant out perennials and shrubs to fill in any unwanted gaps in you borders. If you are not sure what to plant, where to plant it or what ‘look’ you are after, then why not take time out from your garden and visit someone else’s for inspiration. The National Garden Scheme produces a booklet that lists open gardens for your to visit (visit Or visit the Woodgate Nursery Garden Show on 16th and 17th May where, amongst other exhibitors, there will be 5 local garden designers on hand throughout the weekend, not only to talk through their designs but also to answer any specific questions that you may have. The Woodgate Nursery team will also be available to answer any plant related questions and give advice on growing your own vegetables.

Prune your penstemons, cut all the old shoots back to the base provided 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). Cut back flowered shoots of Choisya to promote a second flush of flowers in autumn and you can still trim lavender plants now by cutting off any old flower heads and about 2.5cm (1 inch) of the current year’s growth.

Look out for signs of black spot on roses. If discovered, black spot can be treated with a systemic fungicide such as Rose Clear. Alternatively you can use Rose Clear to prevent the onset of black spot, by spraying your roses before the disease sets in and then spray them every 2 weeks.

Lawn care

For the first mowing in spring, you will have normally set the cutting height to the highest setting. Now we need to think about gradually reducing the height of cut until the desired height is reached. Regular mowing once a week will produce the best results.

We suggest you avoid excessively close mowing, as although attractive, it can weaken the grass, encouraging shallow rooting and making the lawn more susceptible to drought, weeds and moss. Also close mown lawns need more frequent feeding and watering which is not a good idea during a hose pipe ban.

If you have sown new grass recently, then don’t mow it until it reaches 3 inches in height and make sure the mower blades are on a high setting when you do.
In the Vegetable patch

There is a lot to sow this month and with many vegetables you can sow one set and then a few weeks later re-sow another to give you a succession of fresh vegetables over a longer period.

Lettuces, French Beans, Runner Beans, Beetroot, Broccoli, Calabrese Cabbage, Cauliflowers, Chicory, Kale, Kohlrabi, Peas, Turnips and Swedes can now all be sown outside.

Sow bean seeds from mid-May onwards. With climbing beans put up the support first, either tee-pees or a cross caned row made from bamboo canes, or a bean net strung between poles.

Many will find the thought of growing vegetables quite daunting and think it is best left to experts. But experts will have started somewhere and they probably still have to regularly consult the seed packets (which are more often than not a great source of information. Should what is detailed on the packets not contain enough detail then the next best option is do some research online or buy a book for beginners.

Alternatively, if you don’t have time to plant seeds, then we grow a wide selection of young vegetable plants in pots at the nursery, which will give you a head start and get you used to growing, and later harvesting, your very own fresh vegetables straight from your garden.

Continue earthing-up potatoes as and when growth appears above the soil. Plant out tomato, cucumbers and pepper plants in grow bags in the greenhouse. Tender vegetables such as courgettes, marrows, tomatoes and dwarf beans should only be planted out once the chance of frosts has gone.

When you harvest rhubarb you should only pick a third of the total amount of stems at any one time, in doing so your  rhubarb plant will be quite content to continue to produce stems for you to harvest. Tie in your sweet peas with plant support rings to encourage them to climb.

In the Fruit garden

Remove blossom and fruits from newly planted fruit trees (for the first year) to allow them to concentrate on putting their energy into establishing themselves, and remember to water them well. Erect netting around your soft fruit plants to prevent birds eating your crop. Fruit cage netting and bamboo canes are available at the nursery.

Loosely tuck straw under your strawberries (so that air can still get in). Take off any runners to encourage the plants to concentrate on growing fruits. If you are in no particular hurry for the fruit then remove the flowers so the plants don’t set fruit in the first year, but concentrate on building their strength for the following year. Water from the bottom in the mornings and protect them against slugs.

General tips

Harden off half hardy bedding plants to acclimatise them to outdoor conditions. Because of the chance of late frosts don’t be tempted to put out tender bedding until the middle of the month and even then be prepared to cover it if necessary.

If it’s dry, attack ground elder, bindweed and horsetail with systemic weed killer painted onto the leaves. Remember these systemic weed killers are indiscriminate and will kill anything they contact. You may need repeated applications of glyphosate weed killer for certain weeds, which unfortunately will keep the plot out of action for a while as it does its work.  If you don’t have time to dig up dandelions, then at least chop their heads off before they set seed.

Keep an eye out for snails and pick them off where you can and don’t forget the slugs are also about; if you find an entire row of seedlings have vanished overnight you can bet it was slugs.

Lift and divide overcrowded clumps of daffodils and other spring-flowering bulbs and relocate as required. Open greenhouse vents and doors on warm days. Check for nesting birds before clipping hedges
Our quick guide to Hanging Baskets

Plant up pots and baskets of summer bedding and harden off before placing in position. In cold areas wait until June.

  1. Choose a basket liner and bracket
  2. Choose the colour scheme or effect that you want to create.
  3. Place the liner in the basket and fill it with a water retaining compost.
  4. We will usually place a vertical growing plant in the middle such as fuchsia, heliotrope, geranium or begonia (the latter two are both good drought resistant plants).
  5. Surround this central plant with trailing plants such as surfinia, lobelia, bacopa or verbena.
  6. You should be able to hang them out by the first week in June, but if in doubt wait until any chance of frost has gone or bring them under cover at night.
  7. You will need to water them regularly, possibly twice a day during hot weather.

We have a large choice of baskets, liners, bedding plants and wall brackets at the nursery or if you would prefer we can make one up to your specifications.

If you would like any more advice then please just ask at the Nursery.