September Gardening: Autumn Lawn Care, Mulching & Spring Bulbs

By Alicia Wheeler - Gardenscape Sales Team/RHS Level 3 Horticulturalist 

September has arrived, and autumn has begun. The trees’ leaves will slowly start to shift into warm tones, while the grass looks far more vibrant thanks to the rain we’ve had. It’s a gorgeous month, perfect for spending time tending to your garden and taking walks in the countryside while enjoying the last of this year’s warm sunshine. It’s an exciting month for harvesting as apples, pears and autumn raspberries are ready to pick. September gardening involves jobs such as lawn care, mulching, and planting spring bulbs for next spring. 

Now is the ideal time to start thinking about mulching your beds and borders. After a busy growing season, many soils will be depleted of nutrients and organic matter. Adding a soil conditioner mulch in autumn helps protect the soil structure over winter, while the soil organisms release nutrients ready for the plants come spring. Mulching also keeps the soil warm, protecting the plant roots during cold weather.

There are many options to choose from, and what works best for you depends on your soil and planting needs. If you have heavy clay soil, adding a layer of manure and grit mix can help break the soil up over winter, saving you from having to dig it into the bed by hand. Mushroom compost is perfect for brassicas with its slightly alkaline pH, whilst peat-free compost is a great all-rounder suitable for most planting. Bark mulches are great to add as a decorative finish to beds and borders, while helping with suppressing weeds and retaining soil moisture.

September is also the time to focus on your autumn lawn care. Adding a lawn topdressing, such as Rootzone, can help improve drainage and level out your lawn. If you are hollow-tining or using a spreader, a kiln-dried topdressing such as our Fine Turf Dressing is the best option. After topdressing, seed your lawn and any patchy areas with a suitable grass seed. The combination of warm soil and increased moisture creates ideal conditions for grass seed to germinate. Finish your autumn lawn care by spreading an Autumn Lawn fertiliser to encourage strong roots and lush, healthy grass.          

As well as grass seed, you can also sow leafy greens such as winter lettuce, pak choi, and spinach while the soil is still warm. You can also plant out spring onions for some harvests this year, and with more to come next spring. 

This month is the perfect time to clear up summer planting and get ready for the new season. Clear out any spent annual bedding plants and empty your summer baskets and containers at the end of the month. Give them a thorough clean so that they are ready for planting up your winter baskets next month.

September is also the time to plant your spring bulbs such as hyacinths, alliums, daffodils, and crocuses. Plant them in well-drained soil in a sunny spot, at a depth of two to three times the height of the bulb. When planting bulbs, more is more! For an impressive display, plant at least 20 bulbs per planting site.                                   

You can also plant hyacinth bulbs for Christmas flowering in September. A good growing mix is multipurpose compost mixed with grit, or a loam-based compost such as John Innes no 2. After planting, move the pots to a cool, dark location outdoors. Leave them there for about 10 weeks, then bring them inside to flower in time for Christmas. 

Enjoy your September gardening!