What to do in the garden in June

Encourage a bountiful harvest by pruning fruit trees in June
Image: encierro/Shutterstock

The longest day of the year falls on June 20th, 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!

For advice on what to cultivate this month, check out this ‘what to sow and grow’ page. In the meantime, here’s a comprehensive list of jobs to take care of in your garden this June:

Timely Tips

Keep on top of your watering
Image: Easy Hose Stainless-steel Hose from Thompson & Morgan

Check plants daily and water them if the soil is dry — especially newly planted fruit trees and shrubs that are still getting established. To help you save money, time & water, it's well worth setting up an automated drip irrigation system.
Harden off any remaining half-hardy bedding plants ready for planting out. Find more bedding plants resources and expert gardening guides over on our hub page.
Use blinds or apply shade paint to prevent your greenhouse from overheating. Remember to open vents and doors on warm days.
Keep on top of weeding. Your plants shouldn’t have to compete for precious water, light, and nutrients.

In the flower garden

Harvest lavender flowers for culinary use or crafting
Image: Lavender 'Hidcote' from Thompson & Morgan

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 annual plants if they're overcrowded.
Lift and divide clumps of snowdrops and bluebells once the leaves start to yellow.
Using rainwater (if possible), continue to water your flowering rhododendrons.
Lift and divide overcrowded clumps of flower bulbs and tubers.
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. Head over to our hub page for links to more fuchsia growing guides and expert advice.
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 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 once 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. For more information and guidance about growing geraniums on our hub page.
Harvest flower heads from your lavender plants to use in baking, crafting, or as a garnish to your meals.

In the vegetable garden

Check and earth up your potatoes as they grow
Image: Potato 'Kestrel' from Thompson & Morgan/Alamy Stock Photo

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. Visit our comprehensive hub page for guidance and advice on growing your own delicious tomatoes.
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 first 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.

In the fruit garden

Water blueberries with rainwater to get the best from them.
Image: Blueberry 'Duke' from Thompson & Morgan

Start to prune your plum or cherry trees now.
Although fruit trees will naturally shed some fruit (called the 'June drop'), aim to thin out congested branches further for bigger and better fruits.
Protect any developing fruits from birds and squirrels by placing netting around your plants.
If you have plants fruiting in containers, remember to give them a high potash liquid feed to keep them healthy and productive.
Top-dress patio dwarf fruit trees with fresh compost and a slow-release fertiliser.
Peg down runners on your strawberry plants to create more plants for next year. If you don't need more plants simply remove the strawberry runners completely. Find more advice and guidance on growing and harvesting strawberries on our helpful hub page.
Always water potted blueberry plants with rainwater, as the lime contained in tap water reduces the acidity of the soil over time.

Looking after your lawn

Make lawn maintenance easier by adding edging.
Image: Eco-friendly Roman Stone Effect Border from Thompson & Morgan

If there hasn’t been much rain, raise your lawn mower blades to reduce stress on the grass.
Water your lawn during hot weather, particularly newly seeded or turfed lawns. Keep new lawns well-watered.
Warm weather encourages rapid weed growth — apply specific lawn weed killer to tackle them.
Feed your lawn with a special lawn fertiliser to encourage healthy green growth.
Recut lawn edges, or install lawn edging to make future maintenance easier.

Other jobs about the garden

Keep your cold frame from overheating by opening the lid on a hot day
Image: Garden Grow Wooden Cold Frame from Thompson & Morgan

Use water butts as much as possible and water your patio perennials and baskets well in hot weather. Start to feed them with a balanced liquid fertiliser every 2 to 4 weeks. If you're interested in container gardening, read our guide covering the best perennial plants for pots.
Make small 'wells' around individual plants so that the water can soak the soil to about 25cm (10in). Merely wetting the surface wastes water, encourages weeds and can lead to surface rooting making plants more vulnerable.
Plant floating pond plants now while the water is warming up. Read our 'how to plant up a pond' for more advice.
Keep removing blanket weed from your pond to allow the plants and fish room to breathe.
Keep an eye out for white powdery mildew on plants. If possible, remove the affected parts and spray with a fungicide to prevent further spread.
Look for aphids on the underside of leaves — rub them off by hand or spray with an insecticide to prevent them multiplying. Alternatively try using a natural pest control such as Lacewing larvae.
Keep an eye out for scarlet lily beetles on your lilies — remove and crush any you see. Also check for the sticky brown larvae on the underside of leaves.
Check for vine weevils by tipping your plants out of their pots and looking for 'C' shaped creamy maggots amongst the roots. Treat with nematodes if vine weevils are spotted.
Invest in pest control to prevent slugs attacking your young plants.
Clip evergreen hedges such as privet, box and yew while they're in active growth.
Open greenhouse vents and doors on warm days.
Check plants in your greenhouse daily and water them if the soil is dry.
Damp down your greenhouse on hot days to increase humidity and deter red spider mites.
Turn the compost in your bins every month to keep it well aerated.
Keep bird baths topped up in hot weather.

From your armchair

Order popular plants and vegetable plants online if you didn't get round to sowing seed this year.
Beat the drought and order ground cover shrubs for years of easy-maintenance colour.