June Garden Tips
The longest day of the year falls on June 21st, bringing warmer temperatures and extra sunlight. Flowers are blossoming, there’s lots to harvest in the vegetable garden and keeping on top of bolting plants is a priority – particularly weeds!
In the Flower Garden
Harden off and move hanging baskets and containers growing on in the greenhouse into their final position. If your hanging basket plants become leggy, trim off the excess to encourage bushy new growth.Continue to thin out drifts of hardy annuals if they are overcrowded. Lift and divide clumps of snowdrops and bluebells once the leaves start to yellow. Lift and divide overcrowded clumps of bulbs. Wait for bulb foliage to die down naturally before cutting back. Pinch out the tips of fuchsias to encourage a bushy habit and more flowers.
Start to pick sweet peas as soon as they flower to encourage more blooms.
Dead-head your roses if they’re repeat-flowering types. Otherwise, leave the seed heads on for decoration.
Dead-head and cut back oriental poppies after flowering. Cutting them close to ground level will stimulate new foliage. Stake tall or floppy perennial plants to prevent wind damage.
As new shoots grow, use soft ties to train climbing plants such as honeysuckle and clematis to their supports.
Prune out overcrowded or dead stems of evergreen clematis they have finished flowering to maintain a good shape. Towards the end of June, if your hardy geraniums have finished flowering, cut them back to encourage new foliage and flowers.
Trees and shrubs
Cut back tender shrubs such as Penstemon, Caryopteris and hardy fuchsias after danger of frosts has passed.
Prune deciduous magnolias once the plant is in full leaf. If this is done in winter, when the tree is dormant, dieback can occur, and pruning in late winter or spring can result in bleeding. Midsummer is therefore recommended.
Clip evergreen hedges such as privet (Ligustrum), box (Buxus) and Lonicera nitida if needed. If they are not too woody, shredded clippings can be added to the compost heap.
Thin out new shoots on trees and shrubs that were pruned in winter to stimulate growth. Remove crossing stems and prevent overcrowding of new growth. Prune out any remaining frost damage from affected evergreen shrubs.
Prune flowering shrubs such as Deutzia, Kolkwitzia, Weigela and Philadelphus 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. Evergreens such as Viburnum tinus can also still be trimmed this month. Rhododendrons can be lightly pruned after flowering. More severe pruning should wait until the following early spring.
Prune overcrowded, dead or diseased stems of Clematis montana once it has finished flowering. Untangling the stems can be fiddly, but once you can see where you are cutting, you need not worry about pruning this plant - it will take even hard cutting back very well. Young mimosa trees (Acacia dealbata) can be cut back once all risk of frost has passed. Mature trees respond less well to hard pruning.Prune wall-trained pyracanthas, removing any shoots coming out from the wall, and shortening other new growth to about 8cm (3in). This encourages spur formation, and increased flowering relative to green growth. Twining climbers (such as honeysuckle and Clematis) need regular tying in and twining around their supports. Tie in climbing and rambling roses as near to horizontal as possible. This will restrict sap flow causing more side-shoots to grow along the length of stem. Therefore more flowers will be produced.
Cut back tender shrubs such as Penstemon, Caryopteris and hardy fuchsias after danger of frosts has passed.
Prune deciduous magnolias once the plant is in full leaf. If this is done in winter, when the tree is dormant, dieback can occur, and pruning in late winter or spring can result in bleeding. Midsummer is therefore recommended.
Clip evergreen hedges such as privet (Ligustrum), box (Buxus) and Lonicera nitida if needed. If they are not too woody, shredded clippings can be added to the compost heap.
Thin out new shoots on trees and shrubs that were pruned in winter to stimulate growth. Remove crossing stems and prevent overcrowding of new growth. Prune out any remaining frost damage from affected evergreen shrubs.
Prune flowering shrubs such as Deutzia, Kolkwitzia, Weigela and Philadelphus 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. Evergreens such as Viburnum tinus can also still be trimmed this month. Rhododendrons can be lightly pruned after flowering. More severe pruning should wait until the following early spring.
Prune overcrowded, dead or diseased stems of Clematis montana once it has finished flowering. Untangling the stems can be fiddly, but once you can see where you are cutting, you need not worry about pruning this plant - it will take even hard cutting back very well. Young mimosa trees (Acacia dealbata) can be cut back once all risk of frost has passed. Mature trees respond less well to hard pruning.Prune wall-trained pyracanthas, removing any shoots coming out from the wall, and shortening other new growth to about 8cm (3in). This encourages spur formation, and increased flowering relative to green growth. Twining climbers (such as honeysuckle and Clematis) need regular tying in and twining around their supports. Tie in climbing and rambling roses as near to horizontal as possible. This will restrict sap flow causing more side-shoots to grow along the length of stem. Therefore more flowers will be produced.
Looking after your lawn
Regularly mow lawns to keep them in shape - removing 'little and often' is the key to a good quality sward. Continue cutting lawn edges with a half-moon edging iron to ensure they are neat.
Add grass clippings to the compost heap in thin layers (too much grass all at once is likely to be very wet and poorly aerated, resulting in smelly slime rather than compost).
Apply a high nitrogen summer lawn fertiliser if not done last month to encourage a healthy-looking lawn - always follow the manufacturer's instructions carefully, as any over-use or runoff can cause water pollution.
Move garden furniture and other objects regularly to allow grass to recover and prevent yellow patches.
Ensure new lawns (either from turf or seed) do not dry out during hot weather, as turves will shrink if allowed to dry out, and fail to knit together.
Troubleshooting
During periods of prolonged dry weather, you could help by keeping your lawn a little longer than usual, and even investing in a mulching mower. Mulching mowers shred the grass clippings very finely and then blow them into the lower layers of the turf, where they act like mulch to help the lawn retain moisture. Because the clippings are fine, the end result is not unsightly, especially later in the season when the lawn gets very dry, and the mulch helps to keep it green rather than brown.
Regularly mow lawns to keep them in shape - removing 'little and often' is the key to a good quality sward. Continue cutting lawn edges with a half-moon edging iron to ensure they are neat.
Add grass clippings to the compost heap in thin layers (too much grass all at once is likely to be very wet and poorly aerated, resulting in smelly slime rather than compost).
Apply a high nitrogen summer lawn fertiliser if not done last month to encourage a healthy-looking lawn - always follow the manufacturer's instructions carefully, as any over-use or runoff can cause water pollution.
Move garden furniture and other objects regularly to allow grass to recover and prevent yellow patches.
Ensure new lawns (either from turf or seed) do not dry out during hot weather, as turves will shrink if allowed to dry out, and fail to knit together.
Troubleshooting
During periods of prolonged dry weather, you could help by keeping your lawn a little longer than usual, and even investing in a mulching mower. Mulching mowers shred the grass clippings very finely and then blow them into the lower layers of the turf, where they act like mulch to help the lawn retain moisture. Because the clippings are fine, the end result is not unsightly, especially later in the season when the lawn gets very dry, and the mulch helps to keep it green rather than brown.
In the Vegetable Garden
Continue to earth up potato plants as they grow. Read our potato growing guide for more advice on growing the best spuds. Keep the compost of newly planted container potatoes moist, but take care not to overwater, as this compacts the soil, squeezing out the oxygen, and prevents the developing tubers from swelling.
Pinch out any side shoots from your tomato plants. You can pot these up to create new tomato plants. Start to feed once the first truss is setting fruit. Harvest salad crops, and resow every 2 weeks for a constant supply of tasty leaves. When planting out cabbages, use brassica collars to prevent cabbage root fly attack.
Harvest early potatoes - these are normally ready about 10 weeks after planting.
Keep an eye on your onion and garlic. When the leaves start to yellow and die back, they’re ready to harvest.
If you haven't already, harden off and plant tender vegetables such as courgettes, squash, tomatoes and sweet corn. Protect crops from carrot fly by covering with horticultural fleece.
Continue to earth up potato plants as they grow. Read our potato growing guide for more advice on growing the best spuds. Keep the compost of newly planted container potatoes moist, but take care not to overwater, as this compacts the soil, squeezing out the oxygen, and prevents the developing tubers from swelling.
Pinch out any side shoots from your tomato plants. You can pot these up to create new tomato plants. Start to feed once the first truss is setting fruit.
Harvest salad crops, and resow every 2 weeks for a constant supply of tasty leaves.
When planting out cabbages, use brassica collars to prevent cabbage root fly attack.
Harvest early potatoes - these are normally ready about 10 weeks after planting.
Keep an eye on your onion and garlic. When the leaves start to yellow and die back, they are ready to harvest.
If you haven't already, harden off and plant tender vegetables such as courgettes, squash, tomatoes and sweet corn. Protect crops from carrot fly by covering with horticultural fleece.
Pinch out any side shoots from your tomato plants. You can pot these up to create new tomato plants. Start to feed once the first truss is setting fruit. Harvest salad crops, and resow every 2 weeks for a constant supply of tasty leaves. When planting out cabbages, use brassica collars to prevent cabbage root fly attack.
Harvest early potatoes - these are normally ready about 10 weeks after planting.
Keep an eye on your onion and garlic. When the leaves start to yellow and die back, they’re ready to harvest.
If you haven't already, harden off and plant tender vegetables such as courgettes, squash, tomatoes and sweet corn. Protect crops from carrot fly by covering with horticultural fleece.
Continue to earth up potato plants as they grow. Read our potato growing guide for more advice on growing the best spuds. Keep the compost of newly planted container potatoes moist, but take care not to overwater, as this compacts the soil, squeezing out the oxygen, and prevents the developing tubers from swelling.
Pinch out any side shoots from your tomato plants. You can pot these up to create new tomato plants. Start to feed once the first truss is setting fruit.
Harvest salad crops, and resow every 2 weeks for a constant supply of tasty leaves.
When planting out cabbages, use brassica collars to prevent cabbage root fly attack.
Harvest early potatoes - these are normally ready about 10 weeks after planting.
Keep an eye on your onion and garlic. When the leaves start to yellow and die back, they are ready to harvest.
If you haven't already, harden off and plant tender vegetables such as courgettes, squash, tomatoes and sweet corn. Protect crops from carrot fly by covering with horticultural fleece.
