August jobs and tips for your garden
August is usually one of the hottest months of the year - making watering essential. Try to use grey water wherever possible, especially as water butts may be running low if it has been a dry summer. August is traditionally holiday-time, so you might need to enlist the help of friends and family to look after the garden while you are away. When you are at home, take the time to prune summer-flowering shrubs. Even though ladybirds are an attractive sight in any garden they are also a great help to gardeners because they are a natural predator of aphids such as greenfly, blackfly and whitefly. So here’s a simple tip to help your plants to survive and thrive – when you see a ladybird in the garden, pick it up and place it in your greenhouse or on your roses, fruit trees or anything you’re worried about. It will make itself at home in no time and hungrily devour the pests.
• Watering! - particularly containers, and new plants, preferably with grey recycled water or stored rainwater.
• Feed the soil with green manures.
• Collect seed from garden plants.
• Cuttings of fuchsias and tender perennials can still be taken which will quickly root at this time of year. The
resulting young plants will be sturdy and over-winter successfully on a windowsill.
• Cuttings can be taken now of houseplants such as coleus..
• If plants being grown in patio pots are not doing as well as expected, this could be caused by either ants
nesting in them or vine weevil. Preventative action should be taken and in the case of ants the pots could
be stood, above the water level in large saucers of water, and in the case of vine weevil treat the compost
with a biological pest control.
• Going away on holiday and there’s no one to water your plants in the greenhouse or conservatory, then it
may be worth considering one of the many watering devices available while away.
• In the case of containers and hanging baskets it is well worth moving them to a situation where they are
shaded and out of full sunshine.
• This is an ideal time to clean out any empty water-butts so that any dirt that may be trapped at the bottom
• Hedges can be given a final trim now before they stop growing.
• Water plants thoroughly when needed instead of every day. Thorough watering supports plants for up 14
days, while merely wetting the surface wastes water, encourages weeds and can lead to surface rooting
making the plants more vulnerable.
• Now is a good time of year to treat lawn chafers and leatherjackets with nematodes.
• Use boiling water as a weed killer on your paved areas. Weeds wilt and die within a few days.
• Don't worry if your lawn is looking brown, the autumn rains will soon make it green again.
• Don't feed your lawn with a high-nitrogen fertiliser now as this will encourage lots of lush new growth which
is easily damaged by autumn weather.
• Lawn growth slows down in late summer so raise the cutting height of your lawn mower to help the grass
• If you're planning on laying a new lawn this autumn, prepare the area now to give it time to settle. This also
allows weeds to germinate so you can clear the area thoroughly before planting. Prepare sites for new
lawns, as towards the end of the month and into early September is an ideal time for sowing. The area
should be level, free from large stones and weeds.
• If your lawn is infested by ants, brush out the nests on a dry day. Always brush them away before mowing.
• If you would like a fine finish to your lawn then cut more than once a week. Any weeds should be removed
and, if required, the holes filled with a gritty compost followed by a small amount of grass seed being raked
• After being away on holiday you will want to cut the grass but to avoid any stress to the lawn it is best to do
this gradually. We would suggest only removing 13mm (½”) of growth to start with, giving another light cut a
week or so later, followed by cutting to the recommended height.
• It is very important to remove perennial weeds as these will be difficult to control until the lawn is
established. Where perennial weeds are growing on the site, spray with a weed killer containing Glyphosate
some weeks before commencing soil cultivations. This will allow any re-growth to be treated for a second
• Harvest sweetcorn and other vegetables as they become ready.
• Water your vegetable plants and fruit plants daily in warm weather.
• Water sweetcorn plants regularly now and feed with tomato food to get the best cobs. Sweetcorn is ready
when you can pop a corn with your thumbnail and the juices are milky.
• Apply a high-potash fertiliser such as tomato food once fruits start to form on peppers, cucumber and
• Keep an eye out for potato and tomato blight and remove and destroy any affected plants immediately to
prevent its spread. The spread of potato blight can occur if conditions are hot and humid, therefore, to
prevent attack it may be worth considering using a fungicide spray. A high potash tomato fertiliser feed
should be applied weekly and don’t let the plants go short of water.
• Continue to feed tomato plants with a tomato fertiliser and remove leaves lower down on the plant to help
with air circulation and prevent disease. Pinch out the top of tomato plants to concentrate the growth into
the fruit that has already formed. Aim to leave 5 or 6 trusses of fruit per plant. The side-shoots on tomatoes
should be pinched out regularly and the leading shoots tied to the supports.
• Cut back herbs now to encourage a new flush of tasty leaves that you can harvest before the frost. Dry or
freeze your herbs to use in the kitchen later on.
• Thin parsley to 25cm between plants so it can establish a good root system before winter.
• Pinch out the tips of your runner bean plants once they reach the top of their support. This encourages
side-shooting and more beans at a manageable height for picking.
• If you're growing aubergines pinch out the growing tip once they have 5 or 6 fruits. Pick fruits while they are
young and shiny.
• Limit the fruits on a squash plant to about three, but make sure these fruits are established before pinching
out the surplus.
• Spring-sown carrots and beetroot will be ready to harvest now although they can be left in the ground to
• Continue to harvest second early potatoes now - perfect for salads!
• Start harvesting your main crop potatoes as the leaves yellow and die back. Try storing your potatoes in
hessian sacks which exclude light but allow adequate ventilation.
• Lift and dry onions, shallots and garlic once the foliage has flopped over and yellowed. Store them in onion
bags to prevent moulds developing.
• Harvest French and runner beans little and often to prevent them from setting seed.
• Pick runner beans regularly to prevent them becoming stringy and to make room for developing pods.
Leaving mature pods to set seed can prevent further flowers developing and reduce your crop.
• Keep harvesting courgettes before they become too big!
• The tips of cucumber side shoots should be pinched out just two leaves beyond any fruit that may be
developing. If any old fruit is left on the plants this will affect further flowering so remember to pick
cucumbers on a regular basis.
• Take cuttings of herbs such as rosemary, sage or mint now to bulk up supplies. Put cuttings in moist, well- drained potting compost (one part grit to one part compost) and place in a cold frame.
• On a dry sunny day, collect seeds of herbs such as dill, fennel, caraway and chervil and dry in a warm spot
out of direct sunlight. Chervil must be sown immediately.
• Established clumps of chives can be divided now.
• Check for cabbage white butterfly eggs under brassica leaves and squash any that you find. Alternatively
use nematodes to kill the caterpillars.
• Clear away any diseased and spent foliage on and around your veg plants to discourage pests and
• Keep on top of weeds as they compete with your crops for nutrients and water.
• As many varieties of peas and beans come to fruition, the challenge for gardeners is to replace them with
some more productive plants so consider onion sets or garlic.
• Sowings of Japanese bulb onion Senshyu Semi-Globe Yellow can be made outdoors from mid to late
August for harvesting in July.
• Sowings can also be made of spring cabbage, Chinese cabbage, corn salad, winter lettuce and radish.
• As you lift your potatoes, why not replace them with Late Season potatoes which will give you a second
crop in October. Main crop potatoes can be lifted as required for immediate use and where they are to be
stored, harvest in September or early October.
• Potato yields can also benefit by being given extra water.
• The tips of any climbing shoots of runner beans should be pinched out should they reach the top of the
• Small, tender courgettes can be regularly picked by using a sharp knife and carefully cutting them off at the
base, protecting sensitive hands from the prickly leaves and stalks by wearing gloves.
• Don’t delay summer pruning fruits trained as restricted forms.
• Keep well-watered during dry spells and weeds under control by hoeing.
• Cut back the fruited canes of your summer raspberries, leaving the new green canes for next year's crop.
Tie in next year's raspberry canes to support wires or fencing.
• The runners of new strawberry plants should be secured into pots of compost or soil allowing them to root.
Plant out any rooted runners of strawberries for a good crop next year.
• Tidy up strawberry plants and remove any old straw from around the plants to improve ventilation and
reduce the risk of pests and diseases.
• The foliage should be removed just above the crown of each plant remembering to clear away any debris.
• Grape vines can be tied to supports.
• Main shoots and side shoots of gooseberries can be pruned back to five leaves encouraging fruiting shoots
for next season to be produced.
• If you have plants fruiting in containers, make sure you give them a high potash liquid feed to keep plants
healthy and productive.
• Remember to feed your lemon tree (and other citrus fruit trees) throughout summer with a special citrus
• Keep birds and squirrels off your berries with netting.
• Harvest your fruit trees - cherries, plums, peaches, nectarines and apricots should all be ripe now! Early
varieties of apple trees will be ready towards the end of the month.
• If you have a glut of autumn raspberries, blackberries or loganberries, freeze them on trays for a couple of
hours and then bag them up to use over winter.
• Prune the fruited stems of your blackcurrant bushes after harvesting.
Pots, Baskets and Containers:
• Thoroughly water at least once a day making sure the compost doesn’t dry out completely.
• As compost can become bone dry in smaller terracotta pots than larger plastic pots any water will run
• It is, therefore, ideal to place pots, baskets, containers in a bowl, bath or even water butt leaving them in
soak thoroughly for a short while.
• Also, just because it may rain, the compost could still remain dry due to foliage not allowing the water
• Deadhead flowering plants regularly.
• Some hardy annuals such as calendula, eschscholzia and myosotis can be sown direct in their flowering
positions obtain early flowers next spring/summer.
• Seeds of perennial plants that can be sown now include cheiranthus (siberian wallflower), cyclamen
hederifolium and potentilla.
• For colourful pot plants in the home, plants of cactus, cineraria, cyclamen, coleus and schizanthus can be
raised from seed sown this month.
• Wild Flowers are becoming popular and sowings of cowslips and primroses should be made in trays,
placing in a cold frame.
• Feverfew and field cornflower can be sown where they are required to flower.
• Now is a good time for cutting plants such as achillea, grasses and other everlasting subjects as they are
at their peak. They should be hung upside down in an airy, warm place so that they can dry naturally ready
for using in arrangements.
• Use bamboo canes to support stems of tall perennials and lilies.
• Deadheading of roses should be done regularly, and flowers trimmed just above the top leaf on the stem.
Stem cuttings can also be taken for propagating.
• Keep your Camellias and Rhododendrons well-watered at this time of year to ensure that next year's buds
• Keep patio container plants well-watered and feed with a liquid fertiliser every fortnight.
• Stake tall or top heavy Dahlias and Lilies to prevent wind and rain damage.
• Dead-head bedding plants and perennial plants to stop them self-seeding and to encourage further
flowering into the autumn.
• Cut back faded perennials to keep borders tidy.
• Dead-head Lilies for a better flower display next year.
• As your Penstemon flowers fade, cut them back to just above a leaf to encourage more flowers.
• Cut back herbs now to encourage a new flush of tasty leaves you can harvest before the frost.
• Prune summer flowering shrubs once they have finished blooming.
• Prune your Wisteria after flowering by removing all the whippy side-shoots from the main branch
framework to about 20cm from their base (about five leaves from the main stem).
• Trim your Lavender plants after they've finished flowering to keep them compact.
• Collect ripened seed and store for next year. Leaving some seed heads in place can be attractive and
allows the plant to self-seed in the surrounding soil.
• Mow wildflower meadows now to help scatter the seeds.
• Take cuttings of your favourite tender perennials such as pelargoniums and fuchsia to propagate them for
• Finish dividing clumps of Bearded Iris now so they have time to form roots and flowers buds for next year
before the cold weather arrives.
• Prune climbing roses and rambling roses once they've finished flowering (unless they are repeat-flowerers
in which case leave them).
• Now is a good time to spray ground elder (and other perennial weeds) with a glyphosate-based weed killer
as the plant has lots of leaf surface area with which to absorb it.
• Look out for symptoms of Clematis Wilt such as wilting leaves and black discolouration on the leaves and
stems of your Clematis. Cut out any infected plant material and dispose of it in your household waste.