What to do in the garden in August

As the summer goes on, Roses become more prone to black spot. Black spot will make the leaves turn yellow and spots appear, some leaves will fall to the ground. This is the ideal time to clear up the diseased leaves and destroy (not in the compost bin) and spray.

I do avoid using sprays in the garden,  but regular spraying of the roses with a good spray such as 'Roseclear' really does work and the Roses are healthier. The current product Roseclear controls the key diseases on roses such as rose blackspot, powdery mildew and rust. It also protects plants from further infestations of aphids and diseases. With the earlier versions of this product, it was necessary to every week or two. It is now recommended spraying interval is 3 - 4 weeks between applications. I don't have shares in the manufacture of Roseclear, although it sounds as if I do, but it does the job.

I don't have shares in Uncle Tom's Rose Tonic either. It's very good. I have brought roses back from the brink with a few applications. Immediately, the rose perked up with signs of new growth. As this rose had been a present, I was keen to get it back on track. I buy this every year because it is good. Shop around this link is for illustrative purposes you can buy on Amazon and other sites.

One reason Camellia and rhododendrons fail to flower in the spring can be a dry autumn. This time of year, Camellia and Rhododendrons are forming buds for next years' display. To ensure plenty of buds and flowers, if it is a dry autumn water well.

Even now it is not too late to cut back some Perennials which are looking faded, such as hardy geraniums, Nepeta (Cat Mint) Alchemilla (Lady's Mantle.) Cut back to tidy shape and when doing this you may notice, at the base and centre of the plant there is already new growth spurting.  After cutting back, the plant may, or may not, flower again depending on the weather, but it will grow new foliage which will look fresh.

I have cut back Alchemilla almost to the ground in early July and by August the new growth has replaced the old and browning foliage. It will not flower again, but the foliage looks much better and fresher.

 Some plants, such as Delphinium, may have very tired foliage and cutting them down may be the only option as the foliage becomes an eyesore.

This is also an ideal time to take cuttings from Pelargoniums and raise plants for free for next year. Easier than most plants to raise from cuttings for a guide on how to take cuttings.

If you have time, ericaceous shrubs such as Camellias and Rhododendrons are forming their flower buds ready for next spring's display. A dry August can reduce the number and size of the buds, water well to avoid this. If you have not fed the ericaceous shrubs catch up by feeding in August and September using a proprietary ericaceous feed.

Under Wildlife & Countryside Act 1981, it is an offence to intentionally damage, destroy or take the nest of any wild bird while it is in use or being built or to  intentionally destroy an egg of any wild bird. This restricts the pruning of hedges during the bird breeding season, but by August it is generally considered that the birds have finished nesting and it is possible to prune hedges.

The Wildlife & Countryside Act 1981 does not prescribe dates but generally, the main bird breeding season is recognised as being between 1 March and 31 July, although it remains the householder's duty to check the hedge first, even outside the main season just to be sure

Depending on the aspect and geography of your veg plot, Onions, Garlic and Shallots should be ready to harvest by the end of the month,/early September. As soon as the top growth goes brown, bend over the top growth, which is said to aid ripening, and then pick a dry spell to ease the bulbs out of the earth carefully before resting them on soil to dry out before bringing in for storage. Onions need to be stored in the light.

Garlic is similar, wait till the top growth turns brown, usually in late August/Sept. Store in a dry and light spot in the warmth rather than a cold area.

After harvesting, you can leave onions and shallots on the ground to dry if there is a decent dry spell.  With our variable weather, it's hard to find a dry spell, and so if the weather is wet, you will need to find another way to dry the onions. It is very important that when onions are put into storage that they are bone dry, if damp, they will rot and quickly become unusable .

There is plenty to do with ongoing tomato care, which is important as the plants are producing many tomatoes. Tomatoes also produce masses of leaves, and these need to be thinned out to encourage fruit production. The tomatoes have set several trusses of flowers by this stage and the top growing point needs to be pinched out to stop the plant growing any taller. The goal is to stop the planting growing and producing yet more leaves and to divert its energy into fruiting.

  Even after pinching out the growing points because tomatoes grow vigorously if allowed, the plant will keep producing new top growth and you will need to keep on pinching out all top growth. The plant will keep growing, keep pinching out and removing leaves so all energy goes to the fruit.

This is the most important time for regular watering and feeding to ensure a good crop of sweet tasting tomatoes. Without the right amount of water and feeding, there will be tomatoes, but of poor quality. More about growing tomatoes.

Late summer is also a risky time for blight to appear. Read what you can do about blight and video advice.

There is still enough summer left to sow last rows of lettuces, rocket and crops such as Pak Choi which prefer cooler conditions and will be less prone to bolting (running to seed prematurely because growing conditions are too hot and dry) Any late crops sown during August will need cloche protection later when it becomes cooler. Also, time to thinking about growing winter lettuces.

 Maincrop potatoes should be ready to be harvested in August/September   It is essential that Maincrop potatoes are stored somewhere dry and dark that is 100% dry and light excluded. 

Strawberries are all over now and so you can use the runners to make extra or new plants for next year. Let the runners develop and peg down into a pot adjacent to the plant so that when properly rooted in a few weeks, the runner can be cut away from the main plant. Strawberry plants need replacing about every 4 years as the yield gets less, so this is an easy way to get extra plants; more about growing strawberries.