Jobs For September

Here's a few ideas of what you could be doing this month...

Top Tip - Green green grass

Revitalise lawns by removing debris that builds up on the surface with a spring tine rake. Then aerate by pushing a garden fork into the ground every 15cm. Finish by spreading a top dressing (a special mix of soil, sand and nutrients) over the surface, working it into the holes with a stiff broom.

Beds and borders

• Regularly deadhead herbaceous plants and cut back those that have started to go over unless they are valued for their winter seed heads.
• Trim mounds of Alchemilla mollis, tall hardy geraniums and peonies to remove old, diseased or tatty leaves. A flush of fresh new growth will soon appear.

Trees and shrubs

• Check tree ties and stakes. Tighten any that are loose or relax ties that are biting into stems - as a rule of thumb, stakes should only be needed to support a tree for 18 months before being removed.
• Plant heathers in soil enriched with composted bark or well-rotted leaf mould.
• Control powdery mildew on roses by spraying shoots covered with the white fungal growth with fungicide. Prevent the disease returning in the future by ensuring soil doesn’t dry out and mulching to retaining moisture.
• Spray ornamental cherry trees with fungicide to control shot hole, a disease that causes brown spots to appear on leaves – as the spots expand the brown patches eventually fall out to leave holes.
• Spruce up Jerusalem sage (Phlomis fruticosa) – cut out dead flowers and thin out older shoots.
• Give evergreen hedges a final cut to keep them looking good until the spring.
• Clip lavenders lightly with a pair of shears after they’ve finished flowering to remove spent blooms. Prune again in spring, removing around 1 in of growth.
• Spread a 7.5cm layer of leaf mould, manure or garden compost around rhododendrons and azaleas.
• Prepare ground for planting new roses. Dig over soil, remove perennial weeds and add plenty of garden compost, manure or another well-rotted, organic material.

In the kitchen garden

• Harvest apples and pears when fruit can be twisted easily from the stems.
• Tidy gooseberries and blackberries. Cut off shoot tips infected with mildew and cut canes that fruited this year to the ground. Tie in the strongest new shoots to canes or supporting wires.
• Prevent the foliage of apple and pear trees from being defoliated by winter moth caterpillars by wrapping sticky bands around the trunk to prevent female moths from crawling into the branches to lay its eggs.
• Plant strawberries in weed-free soil that has been given a boost by digging in some well rotted farmyard manure.
• Save the last of your tomatoes from frost - cut off entire bunches of fruit waiting to ripen and place out of direct sunlight indoors. In a week or so they should turn red.
• Reduce asparagus stems to within 5cm of the ground when the ferny foliage starts to turn yellow.
• Plant out spring cabbages 15cm apart in rows 30cm apart. Cover with fine mesh or fleece to prevent birds from eating the leaves.
• Sow early carrots such as ‘Amsterdam Forcing’ and ‘Early Nantes 2’ in the ground and cover with a cloche for an early crop next year. Alternatively grow in pots placed in the greenhouse.
• Pick yellowing leaves off Brussels sprouts and ensure stems are staked to prevent them collapsing in windy weather.

Gardening under cover

• Wash shade paint off greenhouses or remove sheets of netting to allow as much light as possible to reach the plants inside.
• Check greenhouse heaters are working properly before the first frosts arrive and replace if faulty.
• Bring houseplants that spent the summer in the garden back indoors before they are damaged by falling temperatures. Remove any dead leaves, flowers and check for pests.
• Close greenhouse vents, doors and windows at night to lock in warmth. Open again in the morning to avoid excessive day time temperatures.