September in the South East of England is a month of gentle transition. The days are getting shorter, the nights cooler, and there’s a sense of change in the air. While the region enjoys a relatively mild climate, with warmer temperatures lingering into early autumn, it’s a time to start preparing your garden for the cooler months ahead. Here are some tailored gardening tips for making the most of September in the your garden.

plants foliage green horticulture September autumn gardening tips

1. Sow Late Crops and Winter Vegetables

September is the last call for sowing hardy vegetables that will provide a harvest during the winter and early spring months. In the South East, the relatively mild autumn allows for sowing crops like winter lettuce, spinach, spring onions, and turnips. Kale, Swiss chard, and winter radishes can also be planted now for an extended growing season.

  • Tip: Use cloches or cold frames to protect seedlings from early frosts and to extend the growing period.

2. Divide and Plant Perennials

With the soil still warm from summer, September is the perfect time to divide and plant perennials. Plants like asters, rudbeckias, and echinaceas benefit from being divided now, as they have time to establish roots before the winter cold sets in. Dividing overcrowded perennials also helps maintain their vigor and encourages more prolific flowering next year.

  • Tip: After dividing, water the plants well and mulch around the base to retain moisture and provide insulation.
plants foliage green horticulture September autumn gardening tips

3. Prepare for Autumn Bulb Planting

September is the prime time to plant spring-flowering bulbs such as daffodils, tulips, crocuses, and alliums. The relatively mild winters mean that bulbs planted now will have plenty of time to establish strong roots before the spring.

  • Tip: Plant bulbs at a depth of two to three times their height, and consider planting in clusters for a more natural and impactful display.

4. Deadhead Late-Summer Flowers

Continue deadheading late-summer bloomers like dahlias, cosmos, and roses to prolong their flowering period into autumn. Removing spent flowers encourages the plant to produce more blooms rather than focusing energy on seed production.

  • Tip: Use clean, sharp scissors or pruners to prevent damage to the plant and reduce the risk of disease.

5. Harvest Late Crops and Store Produce

September often means an abundance of ripe fruits and vegetables. Keep harvesting apples, pears, tomatoes, beans, and courgettes as they ripen. Collecting fruits and vegetables regularly encourages plants to keep producing.

  • Tip: Store excess produce in a cool, dry place, or consider preserving them by making jams, chutneys, or freezing them for later use.

6. Start Composting Fallen Leaves

 Woodlands and gardens will soon be shedding their leaves. Take advantage of this natural resource by starting a leaf mold pile. Leaf mold is an excellent soil conditioner, improving structure and water retention. Collect fallen leaves in a separate compost bin or simply pile them up in a corner of the garden.

  • Tip: Use a lawnmower to chop up leaves before composting. This speeds up the decomposition process and makes for a finer leaf mold.

7. Check for Pests and Diseases

With the cooler weather, some pests may become more active. Check for slugs, snails, and caterpillars that could be feasting on your late-season crops. Also, inspect plants for signs of powdery mildew and other fungal diseases, which can thrive in the damp, cooler conditions typical of September.

  • Tip: Remove any affected plant material promptly, and consider using organic treatments such as neem oil or a homemade garlic spray to deter pests.
plants foliage green horticulture September autumn gardening tips
plants foliage green horticulture September autumn gardening tips
plants foliage green horticulture September autumn gardening tips

8. Prepare Your Lawn for Winter

If you have a lawn, September is a great time to give it some attention. Scarify to remove thatch, aerate to relieve compaction, and apply a slow-release autumn fertilizer to encourage strong root growth. Overseeding any bare patches will help your lawn recover from summer wear and prepare it for the cooler months.

  • Tip: Rake fallen leaves off your lawn regularly to prevent them from blocking light and air, which can cause the grass to yellow or develop diseases.

9. Plan and Prepare for Winter

Take some time this month to think about your garden’s needs for the coming winter. Consider which plants might need protection, such as tender perennials or young shrubs. Order fleece or other materials to protect these plants when temperatures start to drop.

  • Tip: Clean and store garden tools, pots, and equipment properly to extend their life. Draining and storing hoses and turning off outdoor taps will prevent frost damage.

 

Gardening in September is all about balance—enjoying the last of the summer blooms while preparing for the coming winter. With a little planning and preparation, you can ensure your garden remains healthy, vibrant, and productive for months to come. Use these tips to make the most of the unique climate and conditions in this beautiful part of the country, and happy gardening!

plants foliage green horticulture September autumn gardening tips