June is usually the month of greatest growth in the garden.
In June the first fruits and all kinds of homegrown vegetables make up for all the work now required in the garden. Pests need to be eradicated, roses looked after, hedges trimmed and lawns mowed.
Soil
Continue to weed and hoe the soil as the weeds will also be having a growth spurt at this time of year.
Vegetables
Outside
Peas, carrots and lettuce can be harvested in the vegetable garden. It is a good idea to make fortnightly sowings of salad crops for continuity.
It is also a good month to pick cauliflowers, broad beans, swede, radishes and dill.
Plant winter greens such as kale and kohlrabi, Brussels sprouts, broccoli and drumhead cabbage.
Chicory can be sown in June in rows in not too rich soil and plant it out after germination in 150mm intervals.
In late June, radicchio, the Italian form of chicory with distinctive red leaves can be planted.
Runner beans that were raised under glass in April will be ready for planting out in double rows 250mm apart – keep plants 200mm apart.
Courgettes can be planted but be aware they take up a lot of space. Just one or two plants produce enough for the whole family.
Plant out courgette seedlings throughout June – they need frequent watering and protection from snails. After 5-6 weeks you should have your first crop.
Vegetables that are growing freely will be all the better for one or two applications of a quick-acting fertilizer or some soakings with weak liquid manure.
If you planted leeks in trenches during mid April, you must start to blanch them as soon as they are well established and growing freely.
Place cardboard or stiff brown paper tubes (150mm long x 75mm diameter) over each plant and draw a little soil up around the base. Support with canes.
Autumn sown onions can be lifted – dig up a few as you require them.
Plant tomatoes, marrows and ridge cucumbers that were raised under glass and are properly hardened off.
Plant sweet corn that was sown under glass in mid May in a sheltered position. Plat 300mm apart.
Earth up March and April planted potatoes – the best results are obtained by doing a little at a time.
In the Greenhouse
As the weather gets warmer, ventilation must become even more free so keep an eye on the thermometer. Nighttime temperatures should be around 16 deg C and daytime 18 deg C.
Cucumbers in greenhouses and frames will be in various stages of growth – some of the earliest plants will be getting past their prime but they can be renovated by cutting out their old laterals that have borne fruit and training young laterals in their place.
The earliest tomatoes will be ripening now – make sure they are watered freely.
Take precautions against carrot fly and cabbage root fly.
Fruit and Berries
Outside
Cherries will be starting to ripen.
Strawberries that have been well watered and fed should be ready for harvest. Always pick in the morning – keep the hull (leaves) in the berry as they keep better that way.
After harvesting, strawberries will produce runners. Select the healthiest of them and allow them to grow. The rest of the runners should be removed so they don’t place an unnecessary drain on the plant.
Finish thinning peaches, nectarines and apricots on walls as soon as the stones are formed. Continue to disbud peaches and nectarines and pinch out the laterals of apricots to encourage fruit spurs to form.
In the Greenhouse
Melons in the heated greenhouse should be swelling well by now and it’s a good idea to sling them in melon nets to take the weight off the stems.
Flowers and Shrubs
Outside
The longest days of the year will see a wealth of perennials and shrubs in full bloom. Your flower garden will be in its glory.
You won’t see any of the biennials you sow this season until next year. Most of them are winter hardy and they will germinate in early autumn.
Sow or plant them in a shady place and prick out as they emerge. Once transplanted into your flower beds, water regularly.
Lat year’s sowings of biennials such as Sweet William, forget-me-nots, sweet rocket and wall flowers will all make June a particularly beautiful month.
The first summer flowers can be cut back and deadheads and shoots removed.
Hedges grown from young plants should be cut right back so they develop good spurs and thicken well.
Evergreen hedges can be trimmed lightly at any time during the month.
Broad leaved shrubs are due for their first cut.
At the end of the month you will be able to take up your spring flowering bulbs once the foliage has died off. Tulip bulbs should be removed every year while daffodils can remain in the ground for years.
Once removed, the bulbs should be dried and labeled. Throw away any rotten bulbs as they can carry diseases – they should not end up in the compost.
June is an ideal time to bring some inside such as gladioli which come in an immense variety of colours and shapes.
Some hardy perennials that have flowered such as delphiniums, daisies and purple cone flowers can be cut back severely as they bloom again in the autumn.
Visit garden centres and nurseries to purchase new plants in flower.
Check stakes of all tall-growing perennials like delphiniums.
Prune late-flowering shrubs like Kerria
Arrange scented plants in pots on patio or terrace.
In the greenhouse
Cinerarias sown in early May must be pricked off 50mm apart.
Sow the large hybrid greenhouse calceolarias now in well drained seed boxes filled with soil or peat-based seed compost.
Cyclamen seedlings that were potted in ealy April will be ready for their final potting into 125mm pots.
A second sowing of primulas can be made following the first sowing in April.
Lawns
Continue to cut and edge lawns
Building
The summer months can be a good time to carry out a lot of new building works as the weather is fine. See also our section on Building in Your Garden.
Other Jobs
Use ecologically sounds ways for pest control. Use a stinging nettle brew as a remedy against pea leaf weevils, aphids, white fly, greenfly, bird cherry ermine, potato beetle spider mites and cherry fruit flies. Take 1kg of nettle before it flowers and soak well in 10 litres of rainwater for 4-5 days. Leave in the sun until it is light and foamy.
Dilute 1:10 in a watering can and spray onto leaves and shoots.
If you do need to use insecticides, a mix of sprays and pellets is recommended as they each have different effects. Short terms poisons work on the surface and long-term killers are taken up by the plant roots.
Don’t use too often as they may encourage the growth of resistant pests.