June is a great time to sit back and enjoy the fruits of your labour, with ornamental borders reaching their peak and some early summer vegetables beginning to flourish. As always, there are jobs to be getting on with but don’t forget to spend a little time relaxing in the garden and make the most of these long summer evenings.
Perennials, Shrubs and Trees
● Lift and divide spring-flowering perennials, including Pulmonaria, to tidy them up and ensure they perform well next year.
● Deadheading will now become a regular task as flowers in all parts of the garden start to go over. The flowering period of many plants can be extended considerably by removing old flowers as soon as they fade.
● Prune mature deciduous shrubs that have finished flowering, including Philadelphus and Weigela. Start by removing any dead, diseased or damaged growth and then cut out one in three of the oldest, thickest stems at the base with loppers or a pruning saw. Growth produced this summer will flower next year.
● Remove suckers from roses, as these are likely to be growing from the plant’s rootstock and therefore not true to type. They will also be diverting energy away from flower production.
● Keep on top of training climbing and rambler roses as well as clematis by tying them in regularly. Roses also benefit from regular deadheading to keep the display vibrant and ongoing. They will also benefit from specialist rose food during the flowering period. Read the instructions in terms of amount and frequency of application.
● Remove the flowerheads of Euphorbia when they are going over. This will encourage new growth from the base of the plant. Always be sure to wear gloves as the milky white sap is a skin irritant. See before and after photos.
● Stake tall-growing perennials. This should be done before the supports are needed so that the plants can naturally grow through them.
● Cut down the foliage of spring flowering bulbs once they have died down. The bulbs can also be lifted, dried and stored or divided, leaving them with time to re-establish themselves over the summer.
● Sow seeds of biennials (such as digitalis, lunaria, sweet william, hesperis, erysimum) to flower next spring. This can be done in trays or small pots. Plant them out into their flowering positions in the autumn.
Kitchen Garden
● Harvest all crops as they mature including early peas, broad beans, rhubarb, beetroot, over-wintered onions, strawberries and perhaps even first early potatoes towards the end of the month.
● Continue to successional sow peas for maincrops later in the year, carrots, beetroot, radishes, kohl rabi, turnips and salad vegetables for a continuous supply of fresh salad leaves throughout the summer.
● Plant out aubergines, celery, celeriac, runner beans, sweetcorn, tomatoes, cucumbers, courgettes and all winter brassicas. Celery and celeriac require a lot of water to produce a good crop in the autumn, so keep well-watered throughout the growing season.
● Remember to pinch out side shoots on your tomato plants and to keep them well supported. Water regularly and feed every 10-14 days with a balanced liquid fertiliser such as Maxicrop Seaweed Extract once the first fruits have start to set. Same applies to aubergines. With cucumbers remember to keep the soil moist but don’t overwater young plants as they are susceptible to rot – and water at the base of the plant, not over the leaves.
● If you are growing your chilies and aubergines in pots in the greenhouse, remember to cover the soil surface with a thin layer of horticultural grit to retain moisture and keep the leaves off the soil.
● Keep a particularly close eye out for cabbage white butterfly caterpillars on the underside of brassica leaves. It is worth continuing to keep them covered with fleece or a fine netting to prevent the butterflies from laying their eggs in the first place.
● Plant herbs in containers in places easily accessible from the kitchen. You can make some great arrangements in a single container by planting several different herbs with contrasting foliage.
● Now is the time to prune peaches, plums and nectarines. In summer, their wounds heal more quickly, leaving them less susceptible to silver leaf disease. Also continue pruning and pinching out shoots on wall-trained fruit.
● Thin gooseberries for larger fruits and keep an eye out for gooseberry sawfly caterpillars, which are most likely to defoliate a plant in summer. One approach is to squash any eggs or caterpillars you discover on the underside of leaves.
● Continue tying in new canes of blackberries and hybrid berries and prune excess growth on vines, pinching out the tip of the fruiting shoots at a leaf beyond three or four developing fruit clusters.
Other Jobs
● June is usually quite warm and dry spells are common. Keep a particularly careful eye on newly planted plants that are yet to fully establish and water them as and when required. It is also a time to consider shading greenhouses and conservatories to prevent plants inside from being scorched. Ensure that your greenhouse is well ventilated during the day.
● Hoe or hand fork annual weeds on a warm, dry day and they can be left on the soil surface to wither. Perennial weeds must still be removed in their entirety to prevent regrowth.
● Consider how you can conserve water. If you have not already done so, spread a mulch of organic matter over any bare soil after rain or watering to help the soil retain its moisture naturally. Plants grow much better when watered with rainwater as opposed to hard tap water which is alkaline. Using water butts to collect rainwater is particularly useful for watering plants that prefer acidic conditions.
● Continue to keep a careful watch on pests and diseases, both inside and outside. Wherever possible, use chemical-free control measures and remember that good garden hygiene and growing practices are one of the best defenses against pests and diseases; healthy plants will be able to shrug off attacks more easily. Consider companion planting as well.
Thank you so much. A busy time ahead!