Experts flag 14 autumn gardening mistakes that can undermine next year’s growth

Gardening experts and practitioners are urging gardeners to avoid a set of common autumn mistakes that can reduce next spring’s display and harm soil and wildlife.

A feature in the Daily Mail outlining 14 frequent errors draws on practical guidance from Neil Miller, head gardener at Hever Castle in Kent, and other horticultural authorities. The guidance stresses timing for planting and pruning, protection of habitats over winter, and simple maintenance tasks that can prevent problems such as disease, soil compaction and weed infestation.

1. Cutting back perennials too soon can harm wildlife and soil. Experts say many gardeners who tidy borders in autumn remove dried flowerheads that provide food and shelter through the colder months. Miller advised leaving dead plant material until late winter, when new shoots begin to appear, because the standing stems also help keep soil covered and reduce erosion.

2. Letting weeds take hold in damp autumn weather increases the workload next spring. The cooler, wetter conditions favour rapid weed growth. Annuals can be hoed out when they first appear, while more aggressive perennials such as bindweed and ground elder often require repeated removal to weaken root systems or, in severe cases, bed clearance and excavation.

3. Missing the planting window for perennials is a lost opportunity. Autumn soil is still warm and moisture levels are higher than in summer, giving new plants a better chance to establish roots before winter. Gardeners are advised to plan purchases for borders according to light and moisture conditions rather than buying on impulse.

4. Buying more plants than can be planted or cared for risks waste. Retail markdowns at the end of the season can tempt gardeners, but plants left in pots or unplanted through winter may not survive and can become a false economy.

5. Sowing some seeds in early to mid-autumn can give seedlings time to establish before winter. Species such as poppies, sweet peas, Ammi majus and larkspur are often started in autumn so they are ready for planting out in spring, provided they are overwintered in a greenhouse, cold frame or a protected windowsill.

6. Delaying orders for spring bulbs can mean favourites sell out. The advisory piece recommends specialist bulb suppliers for reliable stock and notes that varieties such as Narcissus ‘Tete-a-Tete’ and tulips including ‘Queen of the Night’ and ‘Belle Epoque’ may run short if purchased late in the season.

7. Planting tulips too early increases disease risk. While many spring bulbs can be planted from September, Miller and other horticulturists recommend waiting until soil has cooled and the first frosts have started, typically later in autumn or around mid-November, to reduce the incidence of fungal diseases such as tulip fire caused by Botrytis tulipae.

8. Leaving fallen leaves where they fall can create hazards and plant problems. Autumn leaves left to rot on paths can become slippery and, if left on flower borders, can smother tender plants. Collecting leaves and composting them into leaf mould creates a peat-free soil conditioner to be returned to beds.

9. Neglecting lawn repair in autumn allows summer damage to worsen. Scarifying to remove thatch, aerating by spiking, reseeding bare patches from mid-September, and applying a top dressing of sandy loam mixed with well-rotted organic matter are recommended to reduce winter muddiness. Guidance on amounts suggests roughly 4 to 8 pounds of top dressing per square metre, brushed into the soil and watered in if rainfall is lacking.

10. Failing to guard plants against wind can lead to root damage and breakage. Staking tall or floppy specimens and using circular supports for bushier plants can reduce wind-rock. Removing straggly growth from roses after flowering can also help prevent root disturbance during autumn storms, while major rose pruning is usually left until winter.

11. Pruning at the wrong time can provoke vulnerable new growth. Most trees and deciduous shrubs should be pruned in late winter or early spring when they can allocate energy to recovery. Miller cautioned that pruning during mild autumn weather can stimulate new shoots that later suffer frost damage.

12. Leaving tender annuals in place breeds disease. Unlike perennials, annuals such as cosmos, impatiens and begonias generally need removing from beds or pots in autumn because their decaying material can harbour pathogens.

13. Walking across borders and lawns in wet weather causes compaction and plant damage. Gardeners are encouraged to use paths where possible and, if entry to borders is required, to distribute weight with a wooden plank to limit compaction around roots and crowns.

14. Overlooking the aesthetic and observational value of the garden in autumn wastes opportunities to learn for the following season. The guidance encourages gardeners to take time to note what performed well, appreciate seasonal colour and structure, and plan adjustments for spring.

The advice in the season-focused guidance reflects customary horticultural practice and immediate practical priorities for gardeners preparing for winter and the coming growing season. It balances ecological considerations—such as retaining winter habitats for insects and birds—with standard cultural practices like timely planting, weed control and lawn maintenance.

Gardeners seeking detailed timing for individual tasks should consult local horticultural services or extension resources, as exact dates can vary by region and year depending on local climate and the onset of frost.