Why gardeners need to start planning for autumn now

High summer is usually a time of sitting back and enjoying the garden: long, warm, pleasant days and plants growing strongly. But this year we seem to have gone straight to the dog days of summer with hot and dry weather that stresses plants by excess heat and not enough water, reduced growth, and burnt-up lawns. Gardeners are probably entitled to feel a little cheated out of the best of their summer. But it is also a time to see what has stood up well to the conditions in order to guide future planting. As expected, Mediterranean plants – lavenders and phlomis, for example – have prospered while cottage garden plants have suffered. Other winners include gaura, roses, perovskia, sedum, santolina, Verbena bonariensis and the smaller salvias. Watering the base of chrysanthemums, dahlias and other sensitive plants with thorough dead-heading will keep flowers coming. Dead-heading will make a small but useful difference to how much water is needed. Later flowering plants such as blue-flowered ceratostigma and Japanese anemones are flowering early, which is very welcome as other summer flowers such as sweet peas are giving over earlier in the heat. Shorts Lawns will green up with the return of rains, so patience is the only option: watering them in a time of water-use restrictions seems a little anti-social. Areas treated as no-mow are more rewarding this year, with spiky grass seed heads and deep-rooted wild flowers – such as knapweed, yarrow and wild carrot – giving a surprisingly bright and pollinator-friendly display. Their sheltered shade keeps the soil relatively cool and provides protection for slow worms and many other insects that are hunted by birds. It is worth taking notes to see what areas can be no-mow next year. Also consider sowing wildflower seeds in the autumn to add to the display next year. Perseverance with watering is needed in the vegetable garden, and for soft fruit, to reap the rewards of months of work as we finally reach peak harvest season. Summer vegetables such as courgettes, cucumbers, French and runner beans, tomatoes and sweetcorn should mature soon and some water to maintain quality is unfortunately likely to be needed. Perseverance is needed in the vegetable garden (Photo: Nicola Stocken) The same goes for salads, although the abundant cucumbers and tomatoes can substitute for lettuces and other greenery. You have to be flexible in a season like this. Growing trays of salad mini-leaves in the greenhouse or light shade is a water-efficient way of growing green salads. Runner beans are especially demanding in a hot, dry summer as they are reluctant to set pods when the nights are hot and the soil dry. They will come into their own once the dewy cooler nights arrive, but for now watering the soil and foliage at dusk will keep them hydrated and might cool the flowers down so pods are set. Remember to water vegetables like courgettes (Photo: Paul Debois) Looking ahead to autumn is unusually attractive this year. It is time to consider what autumn planted bulbs are needed. Most garden bulbs, alliums, daffodils and tulips come from regions with hot summers, so their reflowering in beds and lawns next year might well be better than usual. Adding more is always wise, but planting fewer than usual this year and splashing out on choice ones for containers is worth considering. Over-wintered vegetables have proven their worth this year as they grow in wetter months. There is scope to sow lettuce and spinach in early September. Plant garlic, onion and shallot sets in October, with broad beans for sowing in November. Guy Barter is the Royal Horticultural Society’s (RHS) chief horticulturist. The RHS is a charity inspiring everyone to grow via its research, advisory, outreach, shows and gardens. For more information, visit: rhs.org.uk