September Gardening Tips
Well summer is fading and we are slipping seamlessly into autumn.
September is one of my favourite months. Traditionally warm, many plants are in their element now whilst others go to seed. As the days start to draw in, we turn our attention to replacing our vests and shorts with jumpers and trousers.
So grab a cuppa and have a read of a few tips to keep your gardening blooming throughout the coming weeks.
Collect seed from annuals. Dry and store in a paper envelope or direct sow to desired area.
Weed. Stop annual weeds going to seed and spreading. Dig out perennial weeds but do not compost.
Keep picking dahlias and deadhead the cone shaped spent flower heads to encourage new blooms.
Deadhead to keep the garden flowering for as long as possible this autumn. Cosmos and dahlia will carry on shining through to late autumn with some TLC.
Stake and feed dahlias, rudbeckias, asters and sedum to keep blooms thriving.
Keep on top of rose black spot by removing affected leaves and picking up all that have fallen on the soil to stop spores returning to the rose roots.
Hanging baskets and pots can be changed from summer to autumn plants; cyclamen, heuchera, heathers.
Plant Hyacinth bulbs from end of September. Force if you want Christmas blooms. Lightly press the bulbs on top of the soil and then leave in a cold dark place for four to six weeks, then bring out in the light and grow on in a greenhouse or indoors. Christmas blooms are magical when you have been part of the process yourself.
Start planning your spring garden and surf the bulb catalogues and shops for autumn bulbs for spring colour such as narcissus, crocuses, scilla, chionodoxa, dwarf iris, snowdrops, anemones and muscari.
See my article at Richard Jackson's Garden website 'What bulbs can I plant for spring interest?' on fab bulbs to plants this autumn.
It is a perfect time of year for autumn planting. Soil is warm and there is time for plants to establish before winter. Plant wallflowers now.
Forage blackberries. Plenty can still be found on hedgerows. Excellent for crumbles and jams.
Bring inside any houseplants that have been outside over these hot summer months.
Plants to prune / trim back AFTER they have finished flowering: Abelia, Lonicera (shrubby honeysuckle), Betula (birch), Carpinus (hornbeam), Jasminum officinale (common jasmine), Passiflora (passion flower).
Net ponds to prevent leaves falling in and sinking to bottom.
Harvest lavender if you have not already or trim spent flowers to prevent plant going woody.
Harvest autumn raspberries, blackberries, late plums, apples and pears. Many veg to harvest at the allotment / kitchen garden: tomatoes, peppers, chillies, pumpkins, squash, sweetcorn, carrots and beetroots.
Put your harvests to good use - try juicing. There are many community juicing schemes, allotment groups and some local businesses that offer a juicing service. Nothing better than being able to drink your own produce!
Many annuals can be direct sown now to let them over winter for next years display such as cornflowers, calendula and nigella.
Sow yellow rattle to assist wildflower areas and suppress aggressive grasses dominating.
Feed flowering plants with organic liquid seaweed and potash to fuel more blooms.
Many herbaceous perennials can be lifted and divided such as hardy geraniums, red hot pokers and lily of the valley. They all finished flowering months ago and so autumn is the perfect time to divide and rejuvenate them. This also increases your plant stock.
Clear dead material to make space for autumn plants.
Try and resist cutting back spent seed heads, many make perfect habitats for wildlife over autumn and winter; for example teasel and phlomis are popular with insects. And the added bonus is they will look great on frosty mornings.
Compost everything you can but avoid anything diseased, woody or perennial weeds.
Scarify lawns to remove thatch and moss. Apply an autumn lawn feed. This will produce healthy green grass. Autumn feeds have low nitrogen so slows grass growth. You do not want prolific growth with winter on the way.
Be water wise. Collect rainwater to water garden and containers.
Take stock of what plants have been successful this year in the difficult conditions from frost and snow to lengthy droughts and start thinking about what edits you will make for next year's garden display.
All photos © Debi Holland Gardening 2021