May is a marvellous month but there is much to do, writes Lisa Young.

Hardening off

There may still be frost so be ready to cover vulnerable plants with fleece, cloches or even newspaper. It’s also the perfect time to use up your plastic bottles, as well as those that your family and friends are planning to leave out for recycling. Cut in half, they make perfect cloches, are free and can be used many times over. A far worthier life than as a single use drink container!


It’s time to harden off the vegetable and flowering plants you have grown from seed and cuttings. Place them outside at the warmest time of the day and build up longer periods of time over a couple of weeks until they finally overnight. If the weather is still cold then protect them with cloches. This acclimatisation helps them better establish when planted as there is not such a shock change to environment.


Thin out the seedlings planted last month and consider adding the thinnings to salads.

Plant out tomato plants in position if you’re certain frosts have passed or in greenhouse for safety. If you’re planting them on the allotment don’t plant them too close to potatoes as both can suffer from blight.


Sow runner and French beans outdoors. Always place supports before planting climbing plants to prevent root damage from pushing poles in at a later date. They are best planted in a sheltered spot as their soft leaves are easily torn in wind. Cane wigwams provide better protection than straight rows. Water well until they grow to the top of the canes and then pinch the tips out so that they bush out in the lower layers. Planting sweet peas nearby will encourage pollinators to the runner bean flowers and promote a good crop.

Brussels sprout, cauliflower, cabbage, sweetcorn and cucumber seeds can be sown indoors or out this month, depending on the weather. Courgettes, pumpkins and other squash can be sown indoors, as can chillies and peppers.

You may wish to resow crops you sowed a couple of weeks ago such as beetroot, carrots and peas so that you have an autumn cropping.

Keep sowing lettuce, kale, Swiss chard, spinach and kohl rabi so that you can enjoy a constant supply throughout the summer and into autumn.

Continue to earth up your potato plants to protect from frost and to prevent the tubers reaching light and turning green and potentially poisonous.

Give globe artichokes a new lease of life by removing the protection you gave them for the winter and feed them with a high-potash liquid or with a rich mulch.

If it’s cold, cloche strawberry plants at night but take the cloches off in the day so that they can be pollinated by insects. Remove unwanted runners.

Lifting and dividing perennial herbs such as thyme, oregano and chives is a lovely job thanks to the aromatic scents released as you handle the plants. Using secateurs clumps can be cut into smaller sections to replant. This doesn’t work on tougher stemmed herbs such as sage and rosemary, however.

To harvest

You may be able to enjoy rhubarb, spring onions, kale, spring cauliflowers and the last of your spring cabbage. Radishes, spinach and lettuces will all be young and full of flavour and goodness.

Asparagus is still producing, it’s best cut an inch below soil and there are special curved, serrated knives to do the job.


It’s time to picture your summer garden and make it so! Sow seeds for your favourite flowers and create a pretty, sweet-smelling haven for pollinators. Sunflowers, sweet peas, zinnia, lupins, aster, cornflowers – there’s an A-Z of seeds to choose from!


Sow marigold and nasturtium seed if you are companion planting – as no doubt you are, after reading last month’s feature on the subject(!) Hoverflies love marigold pollen and in return will help pollinate your plants and eat pests such as aphids.

This winter’s and next spring’s bedding plants can be sown including pansies, daisies, foxgloves and wallflowers.

Dahlia tubers can be planted once frosts have gone.

Weeds It’s best to hoe regularly so that weeds never get too strong. Hoeing with a sharp blade on a dry day is best so that the cut weeds can wilt and die although it is safer to remove them to stop any possible re-rooting. Following up with mulch and compost will make it harder for the weeds to grow again and the compost obviously gives your plants a boost of goodness too.

Covering the soil makes it difficult for weeds to grow. Many growers use black plastic or landscape fabric on beds to block out the light that the weeds are growing to while the crops can continue to grow unchecked through holes that are cut to suit.

Filing space between rows reduces the amount of space open for weeds and it’s worth researching what plants suit eachother. For example, intercropping slow growing sweetcorn with fast growing lettuce make a good match as the sweetcorn leaves provide shade to the lettuce. The perfect cuppa Now is the perfect time to treat your veg and flowering plants to a fortnightly liquid feed. 

Now is a good time to feed the spring bulbs to encourage flowering next year and to prevent them coming up blind. Plants in containers will also benefit from feeding every fortnight or so as they come into their strongest period of growth.

Hedging A reminder that it is illegal to damage or destroy a nest of any wild bird while it is being built or used. Check your hedges carefully before taking the shears to them certainly up until August.


This article was first published in Smallholder magazine. Get your copy by subcribing here or buy from your local newsagent.