As part of August's plant of the month we will be answering a few seasonal gardening questions.
Q – ‘My summer bedding is starting to fade after the recent hot weather, what can we plant now and enjoy for late summer colour?’
As we enter August we start to enjoy a wide selection of plants for later Summer or Autumn colour. One of the most popular is cyclamen with their colourful flowers. Pansy’s and viola will also last well into the Autumn with weeks of colour. If bedding isn't what you are looking for in early August we have the repeat flowering Hebe Addenda with their large evergreen leaves and full clusters of flowers, some have variegated foliage. Heuchera with their wide variety of colourful leaves offer many Autumnal shades of brown yellow and bronze.
Q – ‘My runner beans have been heavily affected with black fly this year, what can you recommend to help?’
Black bean aphid are up to 2mm long and are mainly black but may have some white flecks on the upper surface of their bodies. Dense cluster of aphids can rapidly develop on soft shoot tips, flower stems and on the underside of the younger leaves. The aphids are often attended by ants, which collect the sugary honeydew that aphids excrete. The ants will also remove aphid predators such as ladybird larvae. Large populations can weaken host plants and can result in stunted growth. On beans, pod formation can be poor if the plants become heavily affected. There are several control methods available, if the population is light allow natural predators such as ladybirds to control the population. If possible manually remove and squash the aphids by hand, however if the problem is large you can use organic sprays, such as natural pyrethrum e.g. Bug Clear Gun for Fruit & Veg, or there are systemic insecticide such as Bug Clear Ultra. Always follow label instructions when using pesticides. On edible plants make sure the food plant is listed on the label and follow instructions on maximum number of applications, spray interval and harvest interval.
Q ‘My hydrangea's leaves and stems are covered in white spores the size of matchheads. How do I deal with this fungus?’
These are not white spores, but clusters of eggs, laid by the hydrangea scale. Typically, these are white and waxy and, as you say, quite large. If you look closely you are also likely to find brown scale insects, like tiny limpets and these have laid the eggs. The scale insect will also lay these eggs on prunus and acer species. The eggs are laid in spring and hatch in mid-summer. Organic sprays, such as natural pyrethrum, Bug Clear Gun for Fruit & Veg, fatty acids e.g. Doff Greenfly & Blackfly Killer, can give good control of scale insect nymphs. These pesticides have a very short persistence and so may require reapplication to keep scale numbers in check. The systemic insecticide acetamiprid e.g. Bug Clear Ultra is also available, follow label instructions when using pesticides.
Q ‘I have harvested my early cropping vegetables and have quite a large area empty, what would you recommend for planting now to get a crop from this autumn?’
The main crops you can sow at this time of year are short growing vegetables and salads many of which are promoted as producing crops in a few weeks. Crops such as radish can be ready in 4 weeks, lettuce leaves in 4-6 weeks or dwarf French beans and beetroot ready for early Autumn you can also sow onion and cabbages seeds ready for cropping next year.
One other alterative novelty crop is planning potatoes for harvesting in time for Christmas, these are available in the garden centre and if we have a mild winter can be grown outside for Christmas potatoes.
Q ‘For the last couple of years my camelia and rhododendron haven't produced that many flowers and the flowers which are produced are quiet small. What am I doing wrong as my neighbours looks amazing every spring?’
The main piece of advice for early Spring flowering ericaceous plants is to water and feed them regularly in the late Summer and Autumn as this is when the plant produces the buds for next year’s flower if the plant is stressed in late Summer or Autumn this will affect next year’s flowers.
I hope the questions above have helped you with a few problems in the late Summer garden. We are always available to help you with gardening questions instore or by email at email@example.com. One of the most important things over the late Summer is to ensure you carry on feeding into September. After the hot whether recently we have all had to increase the amount of water we give our plants and this will have meant some of the food you have previously given the plants will have been washed away.