GardenAdvice gardening calendar final week in September 2026
The final week of September is a useful turning point. The soil often retains summer warmth while cooler air and autumn rain help new roots establish. This week, focus on improving soil, filling gaps in borders, repairing lawns and preparing tender plants for the first frost. Choose jobs according to your local weather and soil conditions.
Plant perennials and spring bulbs
Look at the gaps that appeared in your borders this summer. Hardy perennials planted into workable soil now have time to begin establishing before winter. Check each plant’s mature size, water it in, and keep mulch clear of the crown. GardenAdvice’s recent article on September-planted perennials explains why a new border takes time to fill out.
Plant spring-flowering daffodils and crocuses for colour next year. You can plan tulip positions now and plant the bulbs later in autumn, when conditions are cooler. For ideas and timing, see GardenAdvice’s autumn bulb guide.
Use finished compost and prepare the heaps
If an existing compost heap contains dark, crumbly, well-rotted material, empty the finished section and spread it on vegetable beds and flower borders. Leave it on the surface so earthworms can gradually pull it into the soil. This is particularly useful as crops finish and beds become available. Keep a clear space around plant stems and crowns. Read GardenAdvice’s advice on compost and soil improvement.
Make room in the heaps for the leaves and healthy plant material that autumn brings. Mix fallen leaves with softer green material rather than packing them into a dense, wet layer. Keep diseased material and persistent weed roots out of a cool household heap.
Repair the lawn while conditions are suitable
Thin patches can be overseeded while the soil remains warm enough for germination. Rake the surface so seed contacts the soil, and keep it moist during dry spells. Where the ground is compacted, aerate it after autumn rain has softened the soil, but avoid working a waterlogged lawn. If you would prefer a mixed grass and clover lawn, consider microclover as part of the overseeding. See how to renovate a lawn in autumn and GardenAdvice’s microclover guidance.
Keep ponds clear of excess material
If blanket weed is still present, gently twist it around a cane and lift it out in stages without uprooting aquatic plants. As leaves begin to fall, remove excessive amounts before they sink and decay. Leave material beside the pond for a day or two so small creatures can make their way back. See the GardenAdvice guide to blanket weed.
Check fruit trees and plan winter pest control
As apples are harvested, note any codling moth damage and review what the pheromone traps caught this season. This will help you decide whether to order replacement lures or traps for next spring. Read GardenAdvice’s codling moth advice.
Winter washing is a later job: once fruit trees and roses have lost their leaves and are dormant, consider a suitable winter wash according to its current label. GardenAdvice’s Vitax winter wash guide describes the usual November-to-February window. Do not spray flowering or leafy plants simply because the calendar has reached autumn.
Prepare vegetables and tender plants for colder nights
Harvest remaining ripe crops, check covers over autumn brassicas and clear finished plants from beds. Prepare a well-drained area for garlic planting in October; see GardenAdvice’s garlic growing guide. Keep an eye on forecasts and move tender pelargoniums and other frost-sensitive plants under cover before a cold night.
A gardening gift to enjoy together
If your partner loves gardening, a GardenAdvice one-day gardening course makes a thoughtful gift. One of our garden advisers comes to your own garden and tailors the day to the plants, projects and questions that matter to you both. It is a practical way to learn together and make a plan for the seasons ahead. The course is available as a gift voucher, so you can choose a date that suits you.
For more specific advice about your own plants and conditions, ask your GardenAdvice garden adviser through MyGardenTeam.
