Gardening by month
Gardening in June
Flowers and Shrubs
Roses are often at their peak in June, providing a wonderfully colourful and and fragrant display with plenty of cut blooms for the house, if desired. As the flowers fade, cut back the dying heads with about six inches of stem. When rhododendron blooms start to go over, remove the brown heads – ideally before the new leaf shoots develop beneath them.
Softwood cuttings of shrubs and perennials can now be taken. Choose a healthy new piece of stem. Cut just above a leaf joint and trim below a leaf joint to provide a cutting about 3-4in long. Insert into pots of good quality multipurpose or seed and potting compost. Keep them watered in a sheltered spot and in around six to eight weeks you should have well-rooted little plants for potting on to individual pots.
Spring-flowering shrubs such as forsythia and philadelphus can have their stems cut back to encourage new growth, which will provide next year’s blooms. The larvae of viburnum beetles eat the leaves of several species of this shrub. Unfortunately, birds tend not to find them attractive so the answer is to pick them off by hand or use a pyrethrum-based insecticide.
Keep newly planted bedding and container plants well watered during dry spells. Hanging baskets are particularly prone to drying out and may need watering up th three time a day in windy, exposed locations. A regular feed with a good quality proprietary fertiliser should help to keep them blooming all summer long, as will dead-heading. Pot-grown cannas and dahlias can now be planted out to their flowering positions to add a tropical touch to the garden.
Hardy annuals which were sown direct in their flowering positions during April and May will probably require thinning out to allow them develop properly. There is actually still just about time to squeeze in a final sowing of seed of hardy annuals if you have any spare spaces in borders.
Seed of hardy perennials such as lupin and echinacea can also be sown outside in short rows in a seed bed. Transplant sedlings to 4in apart as they develop during the summer before planting out to their permanent positions in the autumn.
Fruit and Vegetables
Keep a regular look-out for side-shoots on greenhouse-grown tomatoes and any outside which you are growing up canes. These need to be removed carefully with the thumb and index finger to encourage the plants to continue growing on a single cordon. It is very easy to miss them, so it is a good idea to check plants at least every other day.
Blueberries growing in containers of ericaceous compost will apprecoite being watered with rain water, especially if you live in a hard water area of the country. Keep raspberries and strawberries covered with fleece or netting as the fruits develop to prevent the crop being devoured by wild birds.
Many fruit trees experience a natural phenomenon known as the ‘June drop’, when many tiny little fruits fall naturally from the tree. Further thinning may also be required. Apples can be thinned to one fruit per cluster of fruitlets, pears to two fruits per cluster. Failure to thin will result in more, but smaller fruits.
Stone fruits such as plum, gage and cherry can be pruned during June. Do not prune them in winter, as this can lead to the introduction of silver leaf fungus. The longest stems on the trees can be cut back while side-shoots can be pinched out when they have formed about five leaves.
Seed of beetroot, courgette, beans (French and runner), salad leaves, sweetcorn and pumpkin can all be sown outside direct in their cropping positions this month now that all danger of frost is past. Recently planted out brassicas may benefit from protection with fine mesh of fleece to deter the activity of the flea beetle which eats holes in young leaves.
Stop harvesting asparagus spears around mid June, even if there is a temptation to continue cropping. The shoots will then produce their characteristic ferny foliage, which should be left to turn yellow and die back into autumn.
Lawns often need cutting once a week as we get into summer. They will also benefit from a feed with a good quality lawn food. Always remember not to exceed the manufacturer’s suggested rate of application. A well edged and fed lawn can often be the focal point of a garden.