September 2025: Gardening Tips and What to Plant

Posted on 9 September 2025

Hello September! We hope everyone had a great August or summer hols with the kids!

We ended our August at the BBC Gardeners’ World Autumn Fair at Audley End, Essex; we had a fab three days (although they were tiring haha), but it was so lovely to meet our customers and talk to avid gardeners about our products. We also gave out lots of samples of our No.23 Peat Free Potting Compost for everyone to try, as we always hear many comments about people not liking peat free compost (they hadn’t tried ours yet haha!). We were also proud to supply the fair with 120m3 of our compost for the garden designers and landscapers to use in their show gardens!

So what do we have going on in September…. oh yes, our new website!! As you can see, we have a new and improved website, with many new features and even some new products 😉 Check out our blog post on how to navigate this new site!

We will also be attending the Gransden Show on the 27th!

Perennials in our Field No.23 Peat Free Potting Blend

General Garden Maintenance:

We have already had a few showers recently, so to prepare for more rain clean out any water butts and check downpipe fittings.
Check that tree ties and plant supports are firmly in place, ahead of autumn gales.
Clean up patios and hard surfaces to get rid of moss and algae. Doing this now will prevent them from becoming slippery during the winter.

Maintain good plant hygiene in your greenhouse by picking off faded blooms and dead leaves before fungal diseases take hold. Throw out or destroy distressed leaves but do not compost them or leave them lying as this could spread the disease.

Houseplants:

Repot any houseplants that have become top-heavy or pot-bound into larger containers, using our Field No.23 Peat Free Potting Blend Compost.
Water houseplants less frequently as we move into Autumn, and move them off particularly cold windowsills at night.

Lawncare:

Maintaining your established lawn:

Apply our No.4 Organic Fine Grade Lawn Dressing as an organic lawn feed; Field 4 contains a naturally balanced quantity of both major- and micro-nutrients, including plenty of potash and phosphate that grass species need to strengthen roots and build frost resistance going into the winter.
Rake thatch from lawns, scarify well-trodden areas by spiking with a garden fork and re-seed bare patches using our No.4 Lawn Dressing to top-dress.
Mow less frequently and raise the hight of cut as your lawn’s growth rate starts to slow in Autumn. This will help the grass withstand the last of the warm, dry weather, and make it more resilient to being walked on when wet weather arrives.

Creating a new lawn:

Prep the ground for a new lawn by forking over, weeding, levelling and firming lightly. Doing this several weeks in advance gives the soil time to settle, so you have an even surface for sowing and laying turf.
Lay turf onto prepared soil and keep it well-watered so it roots in well. Our Field No.26 Turfing Soil is ideal where levels need to be raised up ahead of turfing.
Sow a wildflower meadow or plant wildflower plugs into existing lawns. Use Field No.30 Wildflower Soil for creating new meadows, or invert areas of existing turf where plugs are planted, to reduce competition whilst plants establish.

Flowers:

Jobs:

Collect ripe seeds from your favourite flowers and store them in labelled envelopes, ready to sow in Spring. This is a great opportunity to increase the number of plants in your garden for free. You can leave sunflower seedheads in place for the birds to feed on.
Lift, divide and replant congested clumps of herbaceous perennials, e.g., Achilleas, once they finish flowering. Dividing regularly will reinvigorate established clumps and ensure that they continue to perform year after year. It also offers an opportunity to multiply your plants. Mix Field No.1 Organic Soil Improver into the planting pit to encourage root growth.

To Plant:

Unless stated otherwise, use Field No.23 Professional Potting Blend compost to form a seed bed when sowing direct, or when sowing in pots and containers.

Spring bedding. For instance, wallflowers, pansies and forget-me-nots in pots and borders.
Spring bulbs, e.g., crocuses, daffodils, hyacinths, bluebells and snake’s head fritillaries in pots and borders. Mix Field No.1 Organic Soil Improver in with the bulbs when planting.
Hardy annuals. Sowing now will provide early flowers; they will bloom a couple of weeks earlier than those from a spring sowing.
- Love-in-a-mist. Sow in modules for planting out later or direct where it is to flower (either in the soil or in pots).
- Cornflowers.
- Queen Anne’s Lace (Ammi majus). This is best sown in autumn, resulting in bigger and better flowers in early spring. Sow direct where it is to flower, or in modules for planting out later.
- Sweet peas. Sow in a cold frame or greenhouse for early summer blooms next year.
- English Marigold. Thes are easy to grow, with autumns sowings that should flower from May. Sow them direct in shallow drills or on the surface of moist peat-free compost (Like No.23) in pots.
- Opium poppy, field poppy, California poppy and ladybird poppy can be sown in autumn for an early summer display. Sow direct on patches of bare soil or in modular seed trays to plant out in spring.

Fruit & Veg:

Jobs:

Pot up herbs, e.g., chives and parsley, and place on a sunny windowsill to use during winter. Use our No.23 Potting Compost.
Cut away any leaves covering the fruits of pumpkins, squash and marrows to help the skins ripen in the sun.
Watch out for wasps – they feast on the juices of split fruits, so pick fruits as soon as they are ripe and pick up any fallen ones. Also try to keep birds off crops like apples and pears; birds peck on these fruits, thus attracting wasps afterwards

To Plant:

Use our No. 7 Seed Compost or No.23 Potting Compost for sowing fruit and veg, or creating drills in the soil.

Sow hardy greens and salad leaves, like kale and land cress, pak choi, mustard and lamb’s lettuce. These are perfect for winter pickings. Sow in a sheltered spot outdoors or grow in pots.
You can plant Saffron crocus bulbs (crocus sativus), so you can harvest your own saffron this Autumn!
Radishes are perfect space fillers as they mature in just a couple of weeks. Sow a late batch of seeds now and the warm soil and mild conditions will ensure that they mature in time for autumn salads.
Onions: planting in Autumn means you’ll get an earlier crop next year. Choose a variety like ‘Troy’ or ‘Radar’ that are ideal for autumn sowing. Sow sets in a sunny spot, 10cm apart, with the tip just showing above the soil.
Peas: hardy peas can be sown in September to overwinter and produce an early crop. Choose winter varieties like ‘Douce Provence’ or ‘Meteor’.
Broad beans: sowing in autumn means plants can establish over winter and crop earlier the following spring. Cover plants with fleece during hard frosts or snow.

You can still sow salads in growbags over winter

Trees & Shrubs:

Jobs:

Complete summer pruning of both free-standing and trained apple trees, to encourage good fruiting in future years.
Collect up and bin apples, plums and pears infected with brown rot, to reduce the spread of this fungal disease.
Plan ahead and collect tree and shrub seeds for sowing next spring, e.g., bladder senna, mulberry and rowan.

To Plant:

If the weather is already autumnal, you can plant and move shrubs and trees without having to worry about their survival and establishment. Shrubs planted now will have all winter to settle in, so will get off to a flying start next spring.