Window boxes: Quite a few window-box flowers have a "summer slump" in their blooming period during August. This often happens in the case of older varieties of petunias and their smaller cousin, million bells (Calibrachoa). To stimulate re-flowering, cut them back vigorously and fertilise them regularly.
Blue spiraea: August is the beginning of the main flowering season for Caryopteris. "Heavenly Blue" is one of the most popular varieties, but Caryopteris clandonensis, also known as "Symphonie in Blue"® is also up and coming at the moment. This new variety stands out thanks to its compact, bushy growth and its thicker, more robust spur shoots. Its many exquisite flowers in beautiful and vivid shades of night blue provide a stark contrast to the backdrop of its shiny, intensely green foliage. Plant roses, summer heathers or grasses around blue spiraea to complement its colour pallet.
Strawberries: It's the best time of year to plant young strawberry plants. Unfortunately, the varieties that are most often offered for sale are more suitable for commercial fruit growing than for your garden at home. You're much more likely to have reliable success with a variety of strawberry that is specifically cultivated for the requirements of a domestic garden.
Garden trees and shrubs: If the deciduous trees and shrubs and conifers in your garden have had their main growth period in July, they will reach maturity in August. This is essential for the branches to withstand winter conditions, so it's best to start using fertiliser on garden trees and shrubs at the beginning of August to ensure that the plants are more resilient during the winter period. You can (or, indeed, should) still add potassium-based fertilisers, as the potassium strengthens the plant tissue, meaning that it can mature with a higher resistance to frost. Around 30 g of potassium-based fertiliser per square metre is usually sufficient.
Stone fruit: August is filled with the smell of ripening stone fruit, such as peaches, nectarines, damsons, plums and Mirabelle plums. However, this also means windfall fruit, which is a wasp's favourite food. It's best to gather the windfall fruit early in the morning, as this is when wasps are least active. This also reduces the risk of being stung.
Lawns: In this warm summer month, it's best not to keep the lawn too short. As a rule of thumb, it's more prudent to have to mow the lawn more frequently than to cut too much off at once. The first time you mow the lawn, cut the grass by approximately one third of its length. After that, keep it to around three or four centimetres in length.
Wanderlust: August is a month for travelling. But who's going to look after your plants while you're away? For potted plants, it's useful to have an automatic watering system with a programmable computer. It's best to install a system like this 14 days before you go away to give you enough time to check that it is watering your plants correctly.
Summer heathers: August is filled with the many colours and shapes of heather plants. The hardiest species include the "bud bloomers", such as those in the "Garden Girls" series. As their buds do not open, they do not wither, meaning that these varieties of heather keep the colour of their pretty flowers right through into November/December.
Grapevines: The first table grapes ripen at the end of August. Garden birds such as blackbirds, thrushes and starlings are particularly fond of these berry fruits. This means that it's worth covering grapevines with netting to protect them against birds. Make sure that the netting is secure enough so that the birds can't eat the grapes through the holes in the net. Check all of the netting daily to ensure that no birds have become entangled.
Courgette: When it comes to courgette plants, the warm and humid weather in August can often lead to severe mildew infestations. If you want to be able to save some of the fruit, it's worth removing any old fallen leaves from the outset. If the infestation continues to develop, it's best to remove all unhealthy plants to prevent the infection spreading around the garden. In such cases, even small courgettes may still be harvested and used.