Watering plants manually during dry spells is time-consuming as they should be “deep-watered” so the water penetrates to the roots, but is essential to keep them alive and well. Wafting water over the foliage of a plant may make you feel virtuous, but does nothing for the plants!
Plants that have been in the garden for a year or more have generally developed a good root system. Apart from plants with rigid leaves – such as hollies – it is generally easy to restrict watering until the plant is noticeably stressed. The leaves will be flaccid and drooping, and plants have a “stretched” appearance. Shrubs around a metre high should be given a full-sized watering can of water (8 litres), sometimes two. Young trees may need several full cans. Give half a can to each needy herbaceous plant. Be aware that water can “run-off” without noticeably penetrating the soil. If you review the plants you’ve watered after an hour they should have noticeably revived. This can help to give you a feel for their appearance when they are in need of water again.
Recently planted specimens have not had time to reach out beyond the former confines of the pot. Get the water right into their base. They only need a small amount, but may need watering every couple of days.
To freshen your garden with new purchases consider drought resistant plants such as Salvias, Sedums, Cistus and Helichrysum. Try the Russian sage (Perovskia atriplicifolia), or even the South African ‘Delosperma’ forms with flowers that blaze like neon.