Gardening in May: what to plant and store in your garden this month
May is one of the richest times of the year for gardeners; with lush seasonal vegetation, flowers invading borders and outdoor spaces taken advantage of as the weather improves.
With the month pulling, it’s finally time to start the gardening work for the summer.
Here are our tips on what works you can get started with to improve your garden space. Good luck!
Gardening work to do in May
Elegantly flowery Iris versicolor ‘Algonquin ‘blooms in May and June in the edges of shallow ponds and bogs. Tor garden plants sells it and a wide range of unusual and beautiful water irises for planting now.
Harden the dahlias
Around mid-May, I start hardening my dahlias so they’re ready to be planted outside at the end of the month. The big new hope this year is Dahlia ‘Jomanda’ and ‘Karma Fuchsiana’, both salmon orange in color, and both also available now as potted plants from pheasantacreplants.co.uk, if you failed to start the tubers earlier.
Cacti and succulents
Cuttings from succulents take up easily at this time of year. Remove a leaf from an echeveria or pachyphytum and set it aside for calluses for a few days, then gently push it into very grainy compost. Soon tiny growths will appear and you will know that it is rooted.
Simply draping netting over fruit bushes is one way to accidentally trap birds: invest in a suitable fruit cage. Northernpolytunnels.co.uk or make small cages from wooden batons and netting that you can lift for harvesting.
If you sowed a small patch of meadow in late fall or early spring, thin it out now, wherever the seedlings sprouted in thick patches, to leave a few inches between each. You will get bigger, healthier plants.
It is the moment of the globe artichoke. Steam for 30 minutes, or until leaves come off easily, then dip in melted butter and lemon juice. Remove winter mulch protection around plants, feed, water and mulch with compost or manure.
Pinch of beans
Pinch off the beans as soon as the flowers seem to ward off the black fly, and give the plants some support if they are tilted. I push a cane into the ground at the end of each row and stretch a string between them.
Now that the currants have finished flowering, ensure good flowering the following spring by cutting the flowering shoots into a strong young shoot further down the stem. Completely cut out about a third of the oldest stems.
Selection of tomatoes
If you plan to plant your tomatoes in pots, consider vintage long tomato pots from long-toms.co.uk. These are made with drainage holes on the sides and should be lightly buried. The roots then escape from the pots and seek moisture. The modern equivalent is Grow Rings, available at Amazon.
Also in May … Beautiful brute
Now Clematis montana has finished blooming, now is a good time to give it a haircut, before it overwhelms your shed. Mow it all over for storage, or cut it hard if necessary. Everything will be fine, although you may have fewer flowers next year.
Spuds you’ll love
Now is the time to ground your potatoes to prevent them from turning green. You should also make sure to plant any that may still linger at the bottom of bags or in egg cartons.
Eucalyptus trees that have gotten out of hand can work just fine as a pruned shrub, and now is the time to do it. Chop yours to the ground now and you’ll soon see some creepy new foliage. You can repeat every few springs.
It’s time to plant new alpine troughs and rockeries. Add a lot of drainage to the base first, then make a half-grain, half-compost mixture. Visit Border alpines to browse a wonderful selection of plants.
We’re so used to cutting off the tips of plants to make them bushy, but chili peppers don’t need it. Do not pinch your fingers or you can delay the first fruits for up to a month. A range of plants is always available at merspringplants.co.uk, although orders were delayed until mid-May.
Look for viburnum beetle larvae, which can severely defoliate plants. They are pale yellow with black markings and are active now, so if you spot any ragged leaves, lift them up and deal with the culprits.
It’s asparagus harvest time and if you think you can never have too many special gardening tools, it’s time to arm yourself with an asparagus knife, for its long, curved blade. There is a beautiful one at worm.co.uk.
Bumblebee on lavender
If you didn’t prune the lavender plants after flowering last year, do so now. Bring them scissors and remove any old flowers from last year, before giving the whole bush a very light cut all over to promote bushy growth.
Penstemons now benefit from being pruned. The growth of last year has now done its job and protected them all winter long, and by cutting you can take softwood cuttings and increase your stock. Each cut should be about 4 to 5 inches long.
Carefully remove the two pairs of lower leaves then insert several cuttings into a compost pot, water and cover with a clear polythene bag and place them in a greenhouse or on a window sill until they are rooted.
Fig with long legs
My fig tree has grown on long legs and grown in the middle, and now is the time to cut it back to stimulate more growth from the base. Not the entire plant, but a branch or two cut off at the base should encourage an influx of new stems.
Remove the heads of wilted daffodils this month
Remove the heads of wilted daffodils and tulips. They will be better next year if they can focus their energy on feeding their bulbs rather than producing seeds. Tying the stems looks silly – let them die naturally.
Carrot and stick
Late April to late May is when carrot flies are on the wing, so if you are direct sowing the following month, be sure to immediately cover your rows with horticultural fleece to keep them away.
Planting beans in a raised bed
If you’ve struggled to keep up with vegetable planting this spring, help is just around the corner in the form of Delfland Nurseries rootball seedlings, which can be purchased by mail order, ready to plant.
May’s deals would normally be the most numerous of the year, as this is the perfect month to plant your patch. However, the nursery only takes new orders for delivery in June in order to catch up with a delay (bioplants.co.uk).
Comfrey is rich in nutrients and easy to turn into an excellent organic fertilizer, even though it is fragrant. Buy plants now of ‘Bocking 14’ (a sterile variety and therefore not as invasive as some comfrey) from organiccatalogue.com
If you have strawberries growing in pots, bring a few into the greenhouse. This will lead to early growth and flowers, as long as you leave the greenhouse door open for pollinators to visit.
Chrysanthemums make wonderful late summer cut flowers. I buy rooted cuttings of ‘Allouise Orange’ to plant them as soon as the frosts have passed (chrysanthemums direct.co.uk).
Wade, elevator, tip
If your water lilies ran out of flowers last year, it might be time to divide. Wade, lift, tip from its planting basket, then use a knife to divide the rhizomes, making sure each has a young shoot. Then replant each one in its own basket and put it back in your pond.
Look for signs of burnt boxes. If you see any affected areas, cut them out and throw them away from the garden. Feed the afflicted boxwood plant well, keep it watered all summer and don’t cut it, and there is a small chance that it will overcome the problem.