July gardening guide: what to do in your garden this July
Summer is well and truly here. The garden is in full swing, with many gardens at their peak, along with a vegetable plot that’s full of produce. It’s such a lovely time of the year in the garden.
At their best in July are delphiniums, agapanthus, lavender, various clematis, achillea, dahlias nepeta thalictrum late-flowering peonies, day lily, roses, sweet peas, honeysuckle; it’s all blooming, and the garden is full of beautiful scents.
July gardening guide: Planting
Grow parsley from seed
Parsley can be tricky to germinate, and July is a good month to try. Sow in a line in the veg plot. Sowing in lines helps you to tell what is germinating seed, which is growing in a line because that is how you have sown it, and what is germinating weeds, which don’t grow in straight lines.
Give parsley some time as it’s slow to germinate. Parsley will survive low temperatures later in the season and is an ideal herb for potting up and bringing indoors later in the year.
Take clematis cuttings
If you want to try your hand at propagating clematis, July is a good time. Cut off a length of the recent growth of around 50cm, and then snip it into bits each about 8-10cm with a pair of leaves. It is important to have the node (the knobbly bit on the cutting ) in the middle of the stem that you are going to use. Discard the very top of the cutting, which will be too soft.
Fill a pot with seed compost, make a few holes and tuck the cutting in with hormone rooting powder if you have some (nice to have but not essential). The trick, and why it works sometimes and not others, is that the cutting must not dry out, but it must not be too wet either, or it will damp/rot off.
Try placing it in a propagator or put a poly bag over the pot and seal tightly with elastic band or string and ensure place warm but out of sunlight. Check weekly for signs of growth. Water gently to ensure it does not dry out.
Make new strawberry plants
In July, you can raise new strawberry plants from the runners. This is helpful as strawberry plants are short-lived, 3 years or so and need regular replacements. This is a way to have new plants for free.
Just place a pot of compost near the plant, peg the runner into the pot, water it properly, and leave it for a few weeks until it is well-rooted. Cut off excess runners to conserve the plant’s energy.
July gardening guide: Care and maintenance
One of the main gardening tasks in July is deadheading the various flowering plants. And if you just have a few minutes to spare in the garden, the time will be well-spent deadheading. It is essential to deadhead to keep summer plants and bedding at their best and to prolong flowering.
The purpose of deadheading is to encourage more flowering once the plant has flowered and set seed, thereby encouraging it to reproduce. Plants are often reluctant to flower again or continuously. Deadheading or cutting off the spent flower head forces the plant back into the cycle to produce flower and seeds again.
For most plants, this just means snipping off the spent flowers, but for some others, it’s a little different. Some plants, like ice plants (Mesembryanthemum), need a lot of attention and constant deadheading.
Some plants need so much deadheading that it can be easier to take the shears to the top growth, and often, a second growth and flush will follow, as with alchemilla mollis (common name Lady’s Mantle). Hardy geraniums (not pelargoniums), chives and nepeta can also be cut back.
There is a specific way to deadhead roses. It is best to snap off, not prune away, the spent flower, and it will break just below the flower bud. An equally well-respected alternative is to prune back from the dead flower to the next leaf joint.
For delphinium, foxgloves and Verbascum, when the flower spike has faded and gone over, cut it back by removing the flower head only, as in just the flower spike, not the whole stem. Side shoots surrounding the flower head may produce a second flush of flowers.
Finally, it is important not to deadhead any plant that you want to display berries or hips later in the year, such as Rosa rugosa or honeysuckle.
Cut back early perennials
Early flowering perennials can look a bit tired by July, and their foliage can become tatty and brown. If these plants are cut back now, many will produce fresh green growth to liven up the border and sometimes even a second flush of flowers.
Good candidates for this treatment are oriental poppies, alchemilla mollis, hardy geraniums, nepeta. Cut back close to the ground, feed and wait a couple of weeks. It can look a bit bare when you first to this.
It seems a bit drastic to razor over alchemilla mollis, but you will be rewarded with a fresh green mound of new leaves in a couple of weeks.
Whether you are growing tomatoes under glass or outdoors, the plants will continue to need a lot of attention. The essential step with tomatoes, to get the flavour and texture right, is to feed and water regularly. By July, the tomato plants will grow vigorously, and it’s important to divert the plant’s energy into fruits, not the foliage.
Nip out all side shoots, and thin down, which means cut off leaves to add light for when the flowers turn to fruit and restrict growth. Once the plant has set 3/4 flower trusses, stop the growing point and keep pinching it out to stop the plant from growing.
July gardening guide: Harvesting
By July, beans, lettuce, rocket, courgette, spring onions, strawberries and many early crops are ready for harvesting. Also, depending on the weather, salad potatoes and early potatoes will be ready to harvest in July. At last, it’s time to start eating and tasting the ‘fruits of your labour’.
When growing potatoes, depending on the summer weather, they need watering during dry spells, especially if grown in containers. Water is key to a good crop, and potatoes in tubs dry out easily.
In addition, if you have time, it helps to get a good crop to “earth up” the potatoes as it allows more potatoes to form as the season goes on. To do this, add more soil to the container, or mound up in the plot so that more of the stalk is covered as the potato grows and more stem appears above ground.
July gardening guide: Wildlife and pests
Check the protective netting around strawberries and other soft fruits if you want to enjoy the crop. You may need to make the net more robust so that squirrels cannot get to your crops.
In particular, look at weighing down the edges of the net so that the squirrels cannot get to the fruits by going under the nets. They are known to be pretty agile and adventurous when it comes to getting to prized fruits.
July gardening guide: Other garden tasks for July
- Apply a summer lawn weed, feed and moss killer if your lawn needs an overhaul.
- Damp down the greenhouse floor each morning to help reduce the temperature.
- Don’t forget to make provisions for houseplants while on holiday.
- Cut back growth in hanging baskets to encourage new flowers, remembering to feed afterwards.
- Turn compost heaps as necessary and use any that is ready as mulch.
- Loosen ties on trees and standard roses if they are becoming too tight.
Top Tip - Leave cut grass on the lawn to preserve moisture if the weather becomes very dry. Also, cut a little higher by raising the height of the blades on your mower if it will get a lot of use through the summer holidays.