Jobs for the September Garden: Essential Tasks for a Flourishing Gloucestershire Garden
As summer fades and autumn begins, September is a pivotal month in the gardening calendar. For Gloucestershire gardens, it’s the perfect time to prepare beds, borders, and lawns for the cooler months ahead. Here are the key jobs for the September garden—with step-by-step instructions to help you do each one properly.
1. Lawn Care and Autumn Feeding
- Scarify the lawn: Use a lawn rake or scarifier to remove thatch and moss. This improves airflow and prevents fungal problems over winter.
- Aerate: Push a garden fork 10–15cm into the turf every 20cm to relieve compaction and aid drainage.
- Overseed bare patches: Sprinkle lawn seed evenly, rake lightly, and keep moist, if it doesn’t rain. This is especially important after the hot summer we’ve jsut had. A lot of lawns have bare patches and now is the perfect time to sow more seed while it is still warm enough to germinate.
- Feed with an autumn fertiliser: Choose a low-nitrogen, high-potassium mix to strengthen roots rather than encourage soft growth. If you have a large lawn it might be worth investing in a lawn feeder. They can save a lot of time and will make sure you get the right distribution of feed.
2. Deadheading and Pruning Perennials
- Deadhead roses, dahlias, and penstemons: Snip off faded blooms just above a leaf joint to prolong flowering.
- Cut back summer perennials: Once leaves yellow, cut to ground level and add to the compost heap.
- Divide large clumps: Lift and split congested plants such as irises and hostas. Replant healthy sections into enriched soil.
3. Harvesting Fruit and Vegetables
- Pick apples and pears: Test readiness by gently cupping and twisting—ripe fruit should detach easily. Another way to tell if the fruit is ripe is when the pips are brown. If they are green it’s too early to harvest.
- Collect beans, courgettes, and squashes: Regular harvesting encourages more crops before frost arrives.
- Lift potatoes: Wait for foliage to die back, then fork gently to avoid bruising tubers. Store in hessian sacks in a cool, dark place.
4. Planting for Autumn and Spring Colour
- Spring bulbs: Plant daffodils, crocus, and hyacinths and other spring flowering bulbs 2–3 times their own depth in well-drained soil. It’s too early to plant tulips yet, they are prone to tulip blight so better planted when the ground is cold.
- Winter bedding: Choose pansies, violas, and wallflowers for reliable winter and early colour. There are two types of wallflower – annuals and perennials. The annuals will be available to buy bare root in garden centres or online later this month. They make great in-fillers in our spring borders.
- Plant Container Grown Shrubs and trees: September’s moist, warm soil helps roots establish before winter. Water in well after planting, even if it rains – it’s important that the roots get a very good soaking in the new soil. I like to tease out the roots a little before planting, especially if they are ‘pot bound’ so they get the idea they need to grow into the soil and not stay in a pot shape.
5. Greenhouse and Polytunnel Preparation
- Clear out summer crops: Remove spent tomato and cucumber plants.
- Clean glass and plastic: Use a mild disinfectant to maximise light penetration.
- Sow winter salads: Try lamb’s lettuce, mizuna, or rocket for cut-and-come-again leaves.
6. Wildlife and Pond Care
- Create log piles: Stack prunings in a shady corner for hedgehogs and insects.
- Clean ponds: Remove decaying vegetation but leave some algae for overwintering creatures.
- Install bird feeders: Offer high-energy foods like sunflower seeds and suet balls.
7. General Garden Maintenance
- Weeding: Pull weeds now to reduce seed spread, it’s easier to take out weeds after a little rain and it’s important to keep on top of them before they start to grow again in spring.
- Mulching: Apply organic mulch around perennials and shrubs to insulate roots and suppress weeds. If you’re not sure what mulch is or how to use it read our guide to garden mulch here.
- Check structures: Inspect fences, trellis, and sheds before winter gales set in.
Final Thoughts on Jobs for the September Garden
September is all about balance—tidying summer growth while laying the groundwork for next spring. By focusing on these jobs for the September garden, you’ll ensure your Gloucestershire garden remains vibrant, healthy, and wildlife-friendly well into the colder months.
