Trees, shrubs and climbers provide shade and are vital natural air conditioners, but spring-planted trees can be quickly exposed to heatwaves and dry spells before their roots are established. Planting in autumn gives them a head start: cooler weather reduces water loss, winter rain keeps soil moist, and by summer they are better rooted and more resilient to heat and drought.
Hardy woody and non-woody perennials also benefit from the autumn advantage. Warm, moist soil fuels root growth, cooler weather reduces stress, and falling weed and pest pressure gives plants a clearer run to establish before spring.
Despite these benefits, spring still dominates gardening habits. Visits to RHS Online Plant Advice pages nearly double over the spring season, versus over autumn. Whist autumn 2025 attracted some 13 million page views between September and November, in Spring 2026, between March and May, this rose to some 25 million page views for plant advice.
Leigh Hunt, Principal Horticultural Advisor at the RHS, says: “Spring may be the season when Britain traditionally gets gardening, but hotter, drier summers mean autumn more than ever also has a crucial role to play. Planting then gives trees and perennials time to establish while soils are moist and rainfall is more reliable.
“Newly planted trees still need regular watering for their first two years, especially in summer, but autumn planting can reduce the pressure during those critical first weeks when roots are establishing.
“If we want gardens to survive longer, hotter dry spells, we need to make autumn planting part of the new gardening calendar. It gives certain plants a better chance and helps gardeners use water more wisely.
“We also need to choose plants with the future climate extremes in mind. Covering both hot and dry with drought and heavy rainfall at times. Trees such as Betula pendula (birch), and shrub Hydrangeas and Rhododendrons are increasingly less suited to many dry gardens in southern England. In contrast, shrubs Abelia and Salvia ‘Blue Spire’, perennials including sedums (stonecrops), sea hollies and even Wisteria are coping with warmer, drier conditions this summer.
“In gardens that additionally have waterlogged soils in winter due to higher predicted winter rainfalls, there’s the added challenge of working out what to grow. Try the trees such as Honey Locust, Gleditsia triacanthos f. inermis 'Sunburst' and Field Maple, Acer campestre and the large shrub Tamarix, Tamarix ramosissima 'Pink Cascade'. More perennial options include Iris ensata and Iris siberica, geraniums, and once established Switch grass cultivars such as Panicum virgatum ‘ Northwind’."
Key benefits of autumn planting include:
Autumn and winter rainfall supports establishment and reduces the need for
watering before drier summers.
Soil holds summer warmth, helping roots grow and settle before winter.
Cooler conditions help plants establish with less stress from heat and drought.
- Stronger roots before spring
Plants build stronger root systems before spring growth begins.
