What to do in August
If you have dahlias feed with a liquid fertiliser such as which is high in potassium, this will improve the flower colour and also help to improve the production of tubers so you can get good plants for next year. If you didn’t grow any dahlias buy a couple in a pot from the garden centre now and start a bed of dahlias, making sure you add lots of organic matter when you plant them as they are hungry plants. Don’t forget to stake them – if not they will flop over. They are such brilliant plants as they will give you cut flowers for months until the first frosts and then you will have them again next year.
Watch out for earwigs and put a pot stuffed with straw on top of one of the canes that you have staked the dahlias with – empty them out every few days to somewhere away from the dahlias – earwigs love them!
Small fruit trees are very susceptible to drought – the fruit is swelling now and so they need plenty of water. Use any grass clippings to put round the base of fruit trees and bushes. It will help retain the moisture.
If you have plums prune your trees as soon as you have picked your fruit – this is the correct time to prune plums and other stone fruits – this will hopefully avoid your plums getting silver leaf as they are now in active growth and the wounds will heal quickly, and at this time of the year there are not so many spores around.
Summer fruiting raspberries should have all the canes that have fruited cut won to the ground now. This helps remove many of the pests and diseases and allows the new canes to ripen properly. If the canes are weak and overcrowded remove those at the same time leaving the new canes about 10cm apart. Make sure they are weed free and give them a really good water. This is the same treatment that is needed for loganberries and other hybrid berries. They fruit on wood made in the previous year, unlike autumn fruiting raspberries, which are cut down in the winter time to the ground and fruit on wood made in the same or current year.
August is a good time to plant strawberries – you can often get runners off a friend but make sure they are pest and disease free. This is an ideal job for new allotment holders. Dig over the ground and make sure it is weed free and add plenty of manure or compost and then in rows 75-90cm apart plant the strawberries, leaving 38-45cm between each plant. Make sure they don’t dry out.
You will get more fruit if you plant them now – if you leave them until September cropping will not be as good. I plant mine through a membrane such as mypex, this really helps to keep the weeds down and then mulch them with some bark chippings, especially if bindweed is a problem.
If you are growing tomatoes remove the tips of the plants now to encourage development of fruit on the top of the plant – this will allow more light to reach the plant. You can also remove any yellowing leaves at the bottom of the plant – exposing the trusses to the light.
Sow salad leaves such as mizuna, mibuna, lambs lettuce, and hardy lettuces such as ‘Winter density’ in gutters and then they can be planted outside for autumn/winter/early spring picking. You can also try winter purslane and land cress – all lovely in salads.
You can also sow spinach for an autumn crop once it cools down a bit – this can be sown directly into the soil.
Try one last sowing of chard – by the middle of the month – this can be harvested in spring and looks wonderful in the middle of the winter.
I like to sow some herbs in a cold frame in pots for winter use. Chervil is a gorgeous herb and parsley always comes in handy in winter soup and stews.