With July comes the start of summer proper. All hints of spring – the tender green foliage, untidy daffodil leaves and fleeting, fragile blossom – are now gone, replaced by stronger, brighter colours and a sense of established luxuriance. Summer bedding should now be romping away, knitting together nicely to create blankets and mounds of saturated colour. Tender plants such as cannas, dahlias and salvias will be getting into their stride, flowering more and more prolifically as the days get shorter again. Vegetable gardens and allotments will be filling-out, leaving less space for weeds to grow. With everything in place, the name of the game through July and August is maintenance, keeping plants happy so that they stay in their prime for as long as possible.
There is plenty to be done in the garden, but in much less of a hurry than in March, April, May or June. This leaves time for relaxation, contemplation, planning and entertaining. It’s so important that we take time out to enjoy our outdoor spaces, otherwise, why should we bother? Take the opportunity to feel a sense of achievement every time you dig potatoes, pick a bunch of sweet peas or discover that a cutting has rooted. And if a plant or project has failed, it’s not too late to start over again. Pots and containers can be replanted or refreshed all through the summer and garden centres will be full of useful fillers (and sometimes bargains) should you find you have any gaps.
The main thing to watch in July is the weather. Some degree of watering is inevitable unless you’ve planned carefully to have a drought-tolerant garden. If it’s hot and dry, the burden of watering will increase and you’ll suddenly find the prospect of rain very appealing. Remember that a shower, even a heavy and prolonged one, will do little to saturate dry pots and hanging baskets. Your neighbours will think you’re crazy, but watering in the rain might be necessary on occasion!
Echinacea pallida and Agastache ‘Blackadder’
Storms are another hazard to be aware of. Some of the worst damage in my garden has been inflicted by violent summer storms which often combine torrential rain, hail and powerful gusts of wind. The three together can be devastating, flattening wildflower meadows, toppling pots, tearing or puncturing large leaves and snapping unsupported stems. I cannot emphasise strongly enough how important it is to support plants well, even those that appear to be supporting one another perfectly adequately. Herbaceous borders and prairie-style plantings are particularly vulnerable to the domino effect of one plant collapsing on top of another and then another. When that happens the aftermath is messy and the situation can be hard to recover. If you didn’t support your plants earlier in the year, do it now and you’ll have peace of mind if and when the storm clouds gather.
Apart from that, July is a month to sit back and appreciate the results of all your hard work. Make the most of this month and next since September marks the start of the new gardening year.
July at a Glance
Plan – take photographs to provide a reminder of what’s looking good and less good in high summer. Choose spring bulbs for autumn planting. Find someone to water your garden if you’re planning a holiday this month or next.
Sow – salad leaves, turnips, French beans, spring cabbages, chicory, kohlrabi, dill, coriander and parsley.
Take Cuttings – hydrangeas, lavender, rosemary, salvias, penstemon, mint, thyme and sage.
Plant – autumn-flowering bulbs such as colchicums, autumn crocuses, cyclamen and nerines. Bearded irises, leeks and brassicas.
Prune – early spring flowering shrubs, rhododendrons, camellias and magnolias, conifers, plums, cherries, damsons, wisteria.
Harvest – seed from spring and early-summer flowering perennials, courgettes, calabrese, French beans, Swiss chard, lettuce, mint, parsley, radish, beetroot, carrots, spinach, spring cabbage, spring onion, garlic, onions, globe artichokes, strawberries, raspberries and loganberries.
Pick – sweet peas, roses, zinnias, cosmos, gladioli, dahlias, lilies, carnations and pinks.
Buy – reduced perennials in your local garden centre – trim back, plant out and water thoroughly to encourage lush new growth. Stock up on plant food. Depending on the weather, it might also be time to invest in a new hose or watering can.
Enjoy – a stroll around the garden or a moment on your balcony after sundown.
Visit – open gardens across the country, but especially those with herbaceous borders. The RHS holds shows at Hampton Court near London and Tatton Park in Cheshire this month.
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Martagon lilies planted in a woodland clearing at Chatsworth.
Although summer conditions suit the majority of house plants, they can suffer from having too much of a good thing.
- Large, dark-green leaves are a sign that a plant has adapted to survive at lower light levels. If positioned in too much sun the leaves may become dull or develop crisp brown edges. Move vulnerable plants away from south and west-facing windows or pull the blinds down during the heat of the day.
- Houseplants drink more when it’s hot, dry and sunny. When the weather is fine, check them every other day and water them whenever the surface of the compost feels dry or the pots feel unusually light.
- Succulents and cacti also appreciate more regular watering during the summer months. If you cease watering them during hot weather they may stop growing and become dormant as they would in their natural habitat.
- Mist regularly, in the morning or during the day, to refresh plants and keep them cool. Use a pump-action plant mister filled with rainwater if you have it. (Tap water is fine for most plants but it can leave chalky deposits on the leaf surface over time.)
- When daytime temperatures rise above 18ºC and nighttime temperatures don’t dip below 10ºC many houseplants will be happy taking a break in the garden. Citrus trees, succulents, bananas, gingers, aspidistras and bird of paradise flowers will all enjoy a spell outside. Position them somewhere sheltered, out of direct sunlight and check on them regularly.
- The same fine weather that encourages plants to grow also encourages pests to multiply and diseases to spread. Keep an eye on houseplants for infestations of aphid, scale insect and red spider mite. Use a natural, organic insecticide promptly to keep pests under control.
- Most of us will take a holiday over the summer. Ask a family member, friend or neighbour to pop in and water your plants whilst you’re away. If that’s not an option, water generously before you leave and move plants away from windows to a cool, shaded spot. Stand plants in shallow trays of water if you’re away for more than a week, or use a self-watering planter. Make it a priority to check on your plants as soon as you return home.
Potting Shed & Greenhouse
- Tomatoes, cucumbers and aubergines need watering regularly in high summer – this is important as erratic watering can cause leaf drop, fruit rot, fruit splitting, loss of disease resistance and reduced production. A high potassium feed applied every week will help to produce juicy, flavorful fruits.
- Help tomatoes ripen by removing the plant’s lower leaves and any side shoots that form (this does not apply to bush or trailing varieties). Partial defoliation will allow plenty of light to reach the fruit.
- Chillies should be watered in the morning as they hate to be wet overnight. Let the plants dry out before watering again.
- To keep plants cool, the doors and windows of my greenhouse are open permanently from now until September, unless cool or stormy weather is forecast. ‘Damp down’ paths with water 2 or 3 times during the day to cool the air and increase humidity.
- Clean and tidy any vacant areas of your shed or greenhouse. If, like me, you have very little room to move inside, choose a fine day to decant the contents into the garden and put things back one by one. Dispose of old garden chemicals, paints, preservatives and batteries responsibly – your local recycling facility should be able to help you do this.
- At the first sign of vine weevil adults (pesky black bugs about the size of a little fingernail) water nematodes into greenhouse borders and pots. The adults only create superficial damage – little notches in leaf edges – but the white larvae can decimate a plant’s root system in no time, causing it to collapse and die. Do not sit idly by and allow vine weevils to flourish as you’ll almost certainly live to regret it!
Terrace & Balcony
- It’s not too late to plant or replant a container if the mood takes you or disaster strikes. Long, warm days mean that plants will quickly establish in their new home. Start with larger plants than you might have done in May or June so that you get instant impact. Add a slow-release fertiliser to the compost and you should not need to feed a great deal for the rest of the season.
- Keep in mind that some plants purchased from garden centres will have been specially prepared to bloom prolifically whilst they are on the sales bench. What often follows is a dramatic slump in flowering as the plant gets back into its normal rhythm. Give exhausted plants a trim and feed and they should start to flower again after a few weeks. Violas, Swan River daisies (osteospemum), diascia, brachyscome, bidens and nemesia respond especially well to a mid-season hair-cut, growing back stronger and brighter.
- If you are going away on holiday, move pots into a cool, sheltered position and water them thoroughly before you depart. They can be returned to pride of place on your return. Take care when moving pots as they can be heavy to lift and awkward to handle. A sack barrow or wheeled platform will reduce the strain on your back.
- Turn glazed and dark-coloured pots if they’re positioned in bright sunshine as they absorb heat, baking the delicate roots inside. Terracotta pots tend to remain cooler as water evaporates through the porous clay.
- Pick flowers in the early morning or late in the evening. Strip off any low leaves and plunge the stems straight into a bucket of fresh water until you have time to arrange them. During the cooler parts of the day, the stems and flowers will be nicely plumped up with water and less stressed, meaning they should last longer in a vase.
- Picking is good for plants like sweetpeas and dahlias as it encourages the development of more flowers – a real win-win situation for us gardeners! Regular deadheading performs a similar function. It’s all about preventing a plant from thinking its job (i.e. the production of seed) is done and encouraging it to keep trying.
- Thin out direct-sown biennials such as wallflowers, stocks, foxgloves, forget-me-nots, violas and honesty. Leave 20-30cm between each plant so that they become strong, well-branched and bushy. Biennials can be lifted and moved into their final flowering positions later in autumn.
- Early-flowering perennials such as oriental poppies, perennial cornflower, lady’s mantle, aquilegia, foxgloves and hardy geraniums can be cut back hard as soon as they start to look untidy or become covered in mildew – they will quickly produce neat mounds of fresh foliage and, if you’re lucky, another flush of flowers. Collect seed and store it somewhere cool and dry if you want to increase your stock of a favourite plant.
- Divide bearded irises once they’ve finished flowering. Remove old flowering stems and then divide the rhizomes using a clean, sharp knife before replanting in a sunny position. Ensure each new segment has a fan of leaves and plant so that the rhizome is exposed on the soil surface, otherwise it could rot. Cut off the top half of the leaves if you can bear it: this will help the rhizomes to re-establish.
- Dahlias and chrysanthemums need support from stakes or canes that will be strong enough to take their full-grown, flowering weight. If you are growing them for cut flowers, consider how you’ll move between plants to collect the best blooms before using nets or string.
- July is a good time to take softwood cuttings – these are made from the leafy growing tips of plants that have not yet developed any woody tissue. Prime candidates are rosemary, lavender, salvia, fuchsia, pelargonium and penstemon. Pop them around the edges of a pot filled with peat-free potting compost and keep them moist, misting as often as you can. Roots should start to develop in 2-3 weeks.
- By now most of the spring bulb catalogues will have landed on your doormat. Summer is a good time to start planning your spring display of tulips, daffodils, crocuses and hyacinths, creating a mood board in an old-fashioned scrapbook or gathering images of colours and varieties you like on Pinterest. New varieties tend to be in short supply and often sell out first, so don’t hesitate if there’s a flower you feel you must have!
Trees, Shrubs & Lawns
- If the weather is warm and dry, reduce the frequency of lawn mowing and lift the mower blades so that the lawn doesn’t become scalped and brown. Only water lawns if you must and do it early in the morning. Watering in the evening can encourage the spread of diseases.
- Prune spring-flowering shrubs like forsythia, philadelphus, lilac and deutzia as soon as they have finished flowering. By removing about a third of the old stems at the base of the plant you will improve the health and vigour of the shrub, encouraging strong new flowering shoots to sprout.
- Trim vigorous climbers such as honeysuckle, jasmine and wisteria to keep long, whippy stems under control. Count 5-6 leaves from the old growth and trim just above a leaf, leaving a spur of new wood. If there are longer shoots you want to keep to create a framework, tie these in with soft twine while they’re still soft and pliable.
- Trim hedges when the new stems start to toughen up and the once-fresh foliage becomes a similar colour to the old. These are indicators that growth is slowing and maturing. Take care not to cut into old, bare wood unless you’ve checked that the plant will regrow successfully. Some shrubs such as lavender will suffer or even die if pruned too hard. Most conifers are the same. Others, like yew, have an amazing ability to regenerate.
- Reshape camellias, rhododendrons and magnolias if they have become untidy. Take out any dead, diseased, crossing or straggly branches. These plants generally don’t need a lot of attention so prune only by exception to maintain a pleasing shape.
- Tidy up rambling roses by removing thin or tangled stems once they stop flowering. Then take away about a third of the flowered stems and tie in the remainder to strong supports. This can be fiddly, awkward work and it’s important to protect your arms and face from flailing, thorny stems.
- It’s important to check shrubs, trees and hedges carefully before you start working on them to avoid disturbing nesting birds. If our feathered friends are still in residence, the pruning can easily wait.
- Feed shrubs after flowering and pruning to encourage the vigorous new growth that will produce next year’s blooms. I treat blood, fish and bone as a good all-round fertiliser. Be sure to apply it evenly and water in afterwards.
- Trees and large shrubs planted in late winter and spring should be watered thoroughly every week for the first year. Do not skimp on this as good irrigation will set them up for life.
Kitchen Garden & Allotment
The area of your garden where you grow fruit and vegetables will be the focus of your attention this month.
- Feed and water regularly. Greedy crops such as courgettes, squash and tomatoes will quickly exhaust the soil’s nutrient supply and will benefit from a granular feed or regular doses of liquid seaweed. Brassicas, leeks and celeriac will continue growing into the autumn and will also appreciate some extra nourishment. Crops growing in pots and containers are especially vulnerable to drying out so keep a close eye on these.
- As with flowers, regular harvesting of crops like courgettes, beans, peas, leafy salads and spinach will ensure that the plants don’t stop growing and producing.
- If you have fruit trees, take long, lush growth back to 2-3 leaves and this will encourage the tree to produce more flowers and fruit next year. There’s definitely an art to pruning fruit trees – if in doubt, seek more detailed advice before brandishing your secateurs!
- Thin out apples so that there are just one or two fruits per cluster. Not only will this improve the size and quality of each apple but it will also stop the tree from putting too much energy into fruiting. Some immature fruit will drop naturally but you may have to give your trees a helping hand.
- Dig potatoes as and when you need them. They are far tastier harvested just before you want to eat them.
- Harvest garlic as soon as the leaves have started to turn yellow and wither. Keep the stems intact and allow them to dry for a day or two before bunching or plaiting them. If it’s dry, you can leave them on the soil surface. Store the dry bulbs somewhere cool and well ventilated to keep them plump and fresh for as long as possible.
- Train climbing and twining crops such as beans, cucumbers and squashes up strong supporting frameworks made from canes, stakes, heavy net or a combination of these. Those types with tendrils should attach themselves but may need a little coaxing in the right direction. Squashes and melons may need tying in and extra support once fruit starts to develop.
- If hungry birds are a problem in your garden, cover ripening crops such as raspberries and strawberries with a fruit cage. Loose netting should be avoided as birds can become entangled in it.
- Use up gluts of fruit and vegetables by making jams, chutneys, sauces and soups that can be stored in the freezer.
- Continue sowing salad crops in small quantities until late summer. Unless you have a lot of mouths to feed, a pinch of seed of each variety sown every three to four weeks will be enough to keep your kitchen well supplied.
- Keep on top of weeds, hoeing or cultivating on dry, sunny days so that displaced seedlings will shrivel up and die. Mulching with homemade compost, straw or mushroom compost will help to suppress weeds as well as conserve moisture and regulate the temperature of the soil.
Wildlife & Sustainable Garden
July is a month of abundance with food for insects and animals in plentiful supply. In a healthy garden, equilibrium should be reached between pests and predators. During the day bees and butterflies will be busy pollinating flowers and you may spot caterpillars munching on specific plants. Leave them be if you can spare their host. Ladybirds, bats, bluetits and swallows will feast on aphids and midges, hopefully reducing their population as the weeks go by. While other birds have finished rearing their young, swifts, swallows and house martins will still be nesting and sparrows may be nurturing a second or third brood. At night, moths will be drawn to night-scented flowers such as marvel of Peru (Mirabilis jalapa), tobacco (Nicotiana), honeysuckle (Lonicera spp.), evening primrose (Oenothera biennis) and hardy gingers (Hedychium spp.). Bats might be spotted at dusk, catching insects as they fly.
If you have a pond, it’s likely to be the epicentre of wildlife activity in your garden, alive with baby frogs, toads and newts, dragonflies, damselflies and all manner of insect life.
- During hot, dry spells, water sources can dry up quickly. Keep birdbaths and ponds topped up with rainwater if you can otherwise tap water in small quantities will be fine. Be sure to have a ground-level water source that’s safe for animals to drink from without falling in and drowning.
- Ponds are fertile, fast-growing habitats that need careful careful management in summer. The smaller they are the more attention they generally need to maintain a healthy balance. Keep ponds clear of invasive pond weeds and marginal plants ensuring there is always a section of clear water for fish and amphibians to surface. A pond where the surface is completely covered will become depleted of oxygen just when it’s brimming with life. Remove dead leaves and flowers before they fall and start to rot. Leave any material you take out of a pond on the side for a day to allow any creatures to crawl back into the water.
- Established native plants should be perfectly resilient in hot weather so do not need watering unless a serious drought develops.
- Start to cut established wildflower meadows in sections from the end of July, leaving a week or so between each cut to encourage diversity. Leave the cuttings where they fall for a day or two to allow any wildlife to find shelter and so that seeds drop to the ground. Then rake off the cuttings and compost them. Finish cutting long grass and meadows before the end of August to allow the species-rich turf to recover before winter. Newly-sown perennial meadows or annual flower meadows do not need to be cut unless they become particularly scruffy and unsightly.
- Water your compost heap if there’s no rain as dry material will not rot down without some moisture.
This article first appeared in The Frustrated Gardener