The days are still warm in late summer but nights are cooler, and the garden noticeably starts to slow down. Plants start to run out of steam and empty patches begin to appear more frequently in the vegetable garden after you’ve finished harvesting. Don’t worry, there are still plenty of tasty things you can sow to plug those gaps, such as spring onions and spinach.
Spring onions are usually started from seeds sown in early summer but there’s still time to raise a crop if you get your skates on. There are lots of tangy varieties to sow in August, which will be ready for harvesting in about eight weeks – ‘White Lisbon’ is popular for its mild white stems and green tops, while ‘North Holland Blood Red’ has striking red stems and green tops. Growing in 30cm (12in) pots is easy. Fill with multi-purpose compost, firm and scatter seeds thinly over the surface. Cover seeds with a 1cm (1/2in) layer of sieved compost. Place in a sunny spot and spray the surface with water. Thin out seedlings to 2cm (3/4in) apart when they’re large enough to handle.
A number of caterpillars feed on cabbages but those of the large cabbage white butterfly are a big nuisance – the ravenous beasts will eat holes in leaves and are capable of boring right into the heart of the vegetable, making them inedible.
If the attack is mild you might be able to nip the problem in the bud by removing the orange, rugby ball shaped eggs and picking the distinctive greyish white and black marked caterpillars off by hand. Alternatively, spray plants with a suitable pesticide, such as Richard Jackson Pest Control Concentrate. A good way of preventing problems in the first place is to cover developing cabbages with ultra fine insect proof mesh.
Pruning apples and pears
Most pruning of apple and pears is carried out in winter when plants are dormant but those with established restricted forms – fans, espaliers and cordons – should give their plants a trim in late summer. Tackling plants at this time helps to control growth, maintain an attractive shape and encourages the formation of buds that will carry fruit and flowers next year. It’s best to carry out work on a dry day as the risk of infection by fungal diseases is much lower. Using a pair of clean, sharp secateurs, start by tackling this season’s shoots. Cut any that are 20cm (8in) long and growing from a side branch, back to one leaf. Any new shoots growing from a main branch should be reduced to three leaves.
Sow some spinach
High in antioxidants and other good stuff, spinach has long been considered a super food. It’s also super fast to grow from seeds and those sown now will provide a crop of leaves for picking by around the end of September. Choose varieties suitable for sowing in summer, such as ‘Scenic’, ‘Toscane’ or ‘Tornado’. Sow seeds 2.5cm (1in) deep in rows spaced 30cm (12in) apart – thin out seedlings to 7.5cm (3in) apart when they are large enough to handle. Another option is to sow seeds in large containers. Keep plants well watered during hot, dry periods to prevent bolting and harvest leaves regularly once they’re large enough to pick.
Grow green manure
Mention manure and most people will think of the slightly whiffy, crumbly brown stuff that can be bought in bags from a stable. However, there’s another type. Green manures are fast growing, nutrient rich crops that are ideal for sowing across bare soil, whether it’s an allotment plot or veg patch. Manures are left to grow for at least eight weeks before being dug into the ground. Apart from giving the soil a nutritional boost, their fibrous root systems will improve its structure and the carpet of greenery will prevent weeds from growing. Mustard, crimson clover and fenugreek are among green manure crops that can be sown now.