Home Jobs September gardening jobs

September gardening jobs

Here are your gardening jobs for the month – with added links if I have more information on the subject. They are all still relevant to do now if you’ve fallen behind or if the weather’s been bad.

Week 1

Keep picking autumn-fruiting raspberries and prune out fruited canes on summer-cropping varieties.

Summer prune apple and pear trees to encourage more fruiting spurs. Put grease bands on fruit trees to catch wingless winter moths.

Plant out rooted strawberry runners and pot some up to bring into the greenhouse later in winter for early fruits.

First autumn raspberries
First autumn raspberries

Vegetables to sow now include lettuces, spinach, land cress, purslane, beetroot, radishes, coriander, spring onions, calabrese, spring greens, turnips for their green tops, Swiss chard, winter spinach and hardy Japanese onions.

Sow hardy annuals to provide early spring blooms – pull up hardy annual plants if you don’t want them to set seed everywhere.

Californian poppy. Aug 12
Californian poppy

Harvest cucumbers regularly to promote further flower development.

Stop watering begonias and Gloxinia so they die down after flowering.

Start watering dormant cyclamen to bring them back into growth after their summer rest.

Dahlia New Baby
Dahlia New Baby

Catch earwigs in upturned pots crammed with newspaper or straw on canes among dahlias and destroy any you find.

Prune Pyracantha and train shoots to supports.

Prepare soil to plant evergreen shrubs and conifers by digging it over and incorporating lots of organic matter.

Lovely bee on lavender
Lovely bee on lavender

Prune lavender to maintain its shape, and take lavender cuttings by pulling off side shoots and inserting them in trays of gritty compost.

Prune rambling roses, removing shoots that have finished flowering.

Plant conifers, shrubs and hedging.

Remove suckers from roses, shrubs and around the base of trees.

Tulips Triumph Mix, May 1
Tulips Triumph Mix

Trim box topiary and hedging.

Hoe and hand weed borders.

Pinch out the tips of wallflowers to promote bushier growth.

Buy spring-flowering bulbs like tulips, crocuses, narcissus and fritillaries.

Calendula Fiesta Gitana
Calendula Fiesta Gitana

Week 2

Sow hardy annuals (Consolida, Calendula, Centaurea, Limnanthes, and poppies) where they are to flower next year.

If you sowed any spring-flowering biennials such as Viola, Digitalis (foxglove) or Erysimum (wallflowers), earlier in the summer, they will now need planting out – nip out the tips to encourage bushy plants.

Deadhead annuals to keep them going until mid-autumn.

Amaryllis bulbs
Ready to plant… my five Amaryllis bulbs

Inspect chrysanthemums for signs of white rust.

Order mature or large plants now for planting next month or once the rains have moistened the soil.

Plant up containers with Hippeastrum (amaryllis) bulbs and prepared hyacinths for a Christmas display.

Vine weevil
Vine weevil adult. Picture; RHS/Joyce Maynard

Now is an ideal time to apply biological controls for use on vine weevil grubs. Target fuchsias, succulents and container plants.

Harvest apples, pears, plums and gages.

Pot up herbs, such as tarragon, to use in winter.

Luscious and easy-to-grow blackberries
Luscious and easy-to-grow blackberries

Prune out fruited blackberry/tayberry/loganberry stems and tie in new shoots to supports.

Plant out garlic, or start cloves in pots to transplant later.

Vegetables to sow now include spring cabbages, Japanese onions, turnips for green tops, winter lettuces, spinach, endive, corn salad, land cress and baby salad leaves.

Autumn gentian Sapphire Selection
Autumn gentian Sapphire Selection

Week 3

Continue to deadhead plants such as dahlias, delphiniums, roses and Penstemon to prolong the display.

Divide any overgrown or tired-looking clumps of alpines and herbaceous perennials, such as Crocosmia. This will invigorate them, and improve flowering and overall shape, for next year.

Continue picking sweetcorn, beans and marrows.

Pink geranium, Aug 12
Pink geranium

Take cuttings of tender perennials, such as Pelargoniums (geraniums). If you don’t have a greenhouse, use a light windowsill to grow them on.

Bring inside tender perennials, such as Fuchsia, Gazania, Lantana and Abutilon.

Some tall late-flowering perennials, such as asters, may still need staking to stop them being blown over in the wind.

Philodendron, Monstera and Dracaena
Philodendron, Monstera and Dracaena

Prune late-summer flowering shrubs such as Helianthemum (rock rose) and give evergreen hedges a final trim to make sure they are in shape for winter.

Start to reduce watering of house plants as light levels drop.

Ventilate conservatories during warmer days but close windows at night.

Pond, June 23
Pond with water lilies

Top up pond water levels when necessary and continue to remove blanket and duckweed. You may need to thin out submerged oxygenating plants, as they can quickly build up and crowd the pond.

Make and repair compost bins so that they are ready for the autumn when fallen leaves will quickly fill them.

Pick ripe apples and store the best in fruit crates.

Everbearing strawberry from Lubera
Whopping everbearing strawberry from Lubera

Dig up strawberry runners and pot them up.

Net autumn raspberries and blackberries to protect them from birds.

Lift and dry maincrop potatoes and store in paper sacks in a cool, dark place.

Overwintered spring onions
Overwintered spring onions

Sow broad beans and hardy peas for early crops next year.

Check pears regularly to harvest when perfectly ripe.

Vegetables to sow now include winter radishes, lettuce and salad leaves, spinach, spring onions, and turnip for its green tops.

Canna with geraniums and dahlia New Baby in the background, August 10
Canna with geraniums and dahlia New Baby in the background

Week 4

This is a good time to plant new perennials, as the soil is still warm, but moisture levels are increasing.

Wait for the first frosts to hit dahlias and cannas before lifting the tubers or rhizomes. In warmer regions, they may be OK left in the ground but cover the crowns with a protective layer of straw or bracken.

If the weather is already autumnal, you can plant and move shrubs and trees.

Backlit Claire Austin rose, Aug 12
Backlit Claire Austin rose

Climbing roses can be pruned once they have finished flowering; side shoots from the main branches can be cut back to a couple of buds. Any dead, diseased or spindly growth should be cut out and new young shoots tied into the supports, from the base. If there is an old, thick and woody, unproductive stem, it can be removed from the base to stimulate more vigorous growth.

Clear dead leaves promptly once they start to fall, as they can be a source of disease. They are useful on the compost heap and can be shredded with a shredder or mulching mower, to help them break down quicker. It is vital to throw out or destroy affected leaves.

When bringing plants indoors, check carefully for any pests and diseases they may have picked up outside, in particular, red spider mite, mealybug, and scale insect. Inspect rootballs and compost for vine weevil larvae and treat where necessary.

Water lily, Aug 12
Water lily

Cover the surface of ponds with netting to stop fallen leaves from entering. Accumulated debris in the pond can encourage the growth of algae and weeds, which will eventually harm fish by reducing available oxygen levels. Remove dead leaves from waterlilies as the foliage dies back. Divide water lilies and other pond plants to increase stocks. Overgrown marginal plants can be cut back. A maximum of 50 per cent of the water’s surface should be taken up with planting.

Vegetables to sow now include winter radishes, lettuce and salad leaves, spinach, spring onions, and turnip for its green tops.

Cleaning the greenhouse is best done before bringing in all your tender plants for the winter. Pests and diseases can hide in tiny nooks and crannies, only to come back to life the following spring. Hose down the structure with a forceful jet of water, and then use safe cleaning products such as Citrox, and a non-abrasive scourer specifically recommended for cleaning glass.

Sweet pea Night Sky
Sweet pea Night Sky

Prune out fruited blackberry stems and tie in new ones.

Sow turnips for spring greens in March and April.

Clear crops once they’ve finished and fork over beds. Cover with spiny branches to deter cats.

Sow sweet peas in a cold greenhouse for early summer blooms next year.