August Notes from the Potting Shed
with Gardening Expert Chris Milborne
The lush freshness of early summer has passed, and August brings drier, windier, and warmer conditions than usual. The soil is parched, and many plants look tired despite the seasonal colour still on display. Late summer blooms such as Clematis, Cosmos, Zinnias, Dahlias, and Sunflowers are at their vibrant peak, while early-flowering plants like Oriental poppies and Irises have faded in the heat.
Normally, I’d lift, divide, and replant some of these herbaceous perennials now, but the dry soil has made that difficult. However, in areas where I applied plenty of organic mulch last autumn and spring, plants like Hydrangeas are coping much better.
Some plants seem to thrive in these conditions - especially those from Mediterranean climates. Hibiscus are full of exotic pink, white, violet, and blue blooms, each lasting just a day but flowering over weeks. Buddleias, loved by butterflies, are thriving too, along with Cistus, Lavenders, Abelias, and Myrtus. Herbaceous perennials like Salvias, Achilleas, Kniphofias, Crocosmias, and Echinops are all flourishing, as are ornamental grasses. My Olives, Bay, and a selection of herbs - Rosemary, Sage, Thyme, Marjoram, and Oregano - are also loving the heat. The peach crop this year has been the best ever - sweet and plentiful.
The roses have been particularly impressive - regular feeding and deadheading has kept them in bloom. Water conservation has been crucial; I collect all possible rainwater and prioritise new trees, shrubs, and perennials, focusing on watering the roots. Containers and hanging baskets get regular water, a weekly feed, and deadheading - so far, they’re still looking great.
Sweet peas need daily picking to prevent seed pod formation, which can halt flowering. Weekly feeding keeps them going strong. Heat-damaged plants can often bounce back with a trim and a good liquid feed, especially once rain returns.
To fill gaps, I plant Dahlias, Echinaceas, Rudbeckias, Heleniums, Coreopsis, and ornamental grasses. Their colours and seed heads add beautiful structure and shimmer in summer light. Tubs of summer bedding also work well for quick visual impact.
August is key for feeding Camellias, Rhododendrons, Pieris, and Azaleas with ericaceous fertiliser and ensuring they're well-watered - especially in containers - as they set flower buds now for next spring. Dry roots now often lead to poor flowering or bud drop later.
In the veg garden, August is all about harvests. Onions and Garlic have done well. Lettuce struggled in the heat, and Peas finished early. Tomatoes in pots have suffered from blossom end rot when watering has been uneven. Removing lower leaves as the fruit ripens helps with air circulation and ripening.
Some seeds sown directly dried out before establishing. I’ve had better success starting seeds in modular trays and transplanting later. Now’s the time to sow for winter and spring crops - lettuce, rocket, spring cabbage, spinach, chard, turnips, Chinese cabbage, and pak choi.
It’s a busy time - pruning, taking cuttings of tender plants like Geraniums, Salvias, and Fuchsias, and managing watering. With spring bulbs arriving next month, planning ahead is already on my mind.
