Tie in sweet peas as they grow to ensure they don’t flop and break their stems. Feed them with liquid seaweed every 14 days to encourage good growth, and remove all dead flower heads to keep the plants flowering.
Remove all dead flower heads carefully from rhododendrons, and feed with an ericaceous plant food such as sequestered iron. Keep container grown plants well-watered.
It is still possible to reseed or over-seed bare or thin areas on an existing lawn, but the seed and young grasses will need regular watering during dry weather.
Plant out frost-tender vegetables, including outdoor tomatoes and cucumbers. Keep young plants well-watered and watch out for any signs of slug damage.
Sow seeds of winter and spring bedding plants such as forget-me-nots, wallflowers, Brompton stocks and winter pansies.
Prune plums, peaches, nectarines and fruiting cherries. Pruning this month limits the risk of silver leaf and bacterial canker.
If you want to give the lawn a quick green-up, feed with a liquid or soluble lawn food – you can apply both of these with a watering can or a hose end diluter.
Continue pulling sticks of rhubarb until the end of the month, then let the plants grow naturally to recover their strength. Giving them a feed of Vitax Q4 or a mulch of manure will ensure a good crop next year.
Plant out summer bedding plants, ensuring the plants are well watered in, and kept moist during dry weather.
Put straw or strawberry mats around strawberry plants, to help stop soil splashing onto the fruits. Now is also the time to cover crops with netting to reduce any bird damage.
Regularly inspect all box trees, topiary and hedges for any signs of box blight. Spray them with Topbuxus Health Mix, two or three times during the growing season.
This is your last chance to harvest asparagus – picking should stop in the middle of June, then feed with a general purpose fertilizer to give plants a boost.
Lawn weeds such as daisies, dandelions, plantain and white clover should be treated with Weedol lawn weed killer. This will kill the weeds and allow the grass to thrive and spread.
Plant out runner bean plants or direct sow seed. Put up the support canes before planting, and protect young plants from slug damage.
Fruit trees naturally shed surplus fruit this month, hence the term ‘June drop’. Unless the crop is sparse, it helps to carefully thin fruits even further, so that the remaining ones grow larger and are of better quality.
Regularly check all lilies for signs of the invasive Scarlet Lily Beetle – they’re easy to identify as the adult beetles are bright red. Pick off and destroy the insects by hand or spray with Provado Ultimate Bug Killer.
Remove dead and fading roses to encourage them to produce more flowers – bush, climbing roses and modern shrub roses should flower again this season. Feed them with a rose food at the manufacturer’s recommended rates.
Cut back dead spring bulb foliage. It’s important to wait until the foliage dies down naturally, as cutting back too early can lead to blindness next year.
During long periods of dry weather, raise the height of mower blades a little – slightly longer grass will be more able to tolerate drought.
Plant out young sweetcorn plants – these are best grown in blocks rather than a single row. Space plants 45cm (18″) apart, keep them well-watered and feed regularly with liquid seaweed.
Aquatic plants can now be planted: waterlilies, marginal and oxygenating plants. If you’re planting into aquatic baskets, always use special aquatic compost, never ordinary compost.
Tie in climbing and rambling roses as near to horizontal as possible. This restricts sap flow, stimulating more side shoots to along the stems, and producing many more flowers.
If you didn’t plant up half hardy annuals and tender perennials last month, you can plant them up now that the danger of frosts has passed. A vast range of plants is available for instant colour.
Transplant leeks and late Brussels sprouts to their permanent positions, for harvesting from January to March. Water and feed them regularly.
Remove duckweed and blanket weed from garden ponds with a net or rake as it appears. Leave the weed on the side of the pond for 24 hours to allow any trapped creatures, like freshwater shrimp and tadpoles, time to return to the pond.
Prune back early-flowering clematis once flowering has finished – alpina, macropetal and montana varieties should also be pruned now if required. Feed all clematis with Vitax clematis fertilizer.
Mulch around newly-planted and established trees, shrubs, roses and perennials to help prevent moisture loss and suppress weeds – use composted bark or bark chippings.
Water and feed all plants growing in pots and containers regularly – rain is never enough. Stand pots and containers in saucers during long periods of dry weather, as this will form a reservoir and help save water.
Prune flowering shrubs such as weigela, philadelphus, deutzia and kolkwitzia after they have finished flowering. If this job is left too late, the new growth put on after pruning may not have sufficient ripening time to flower well next year.
Remove any reverted growths on all hardy, variegated plants such as euonymus, eleagnus and rhamnus. Shoots that have reverted are much more vigorous than the variegated plant.