We’re seeing each year that autumn remains enjoyably warm and sunny, so we suggest looking at autumn as an extended albeit milder summer period to enjoy your outdoor space. Autumn bedding plants will be coming into their own soon and of course there’s plenty of tidying to do over the next few months as the year draws to an end.
  So that’s what to expect as we march ahead, but for now we’ve collected our jobs list for the month of August, covering garden maintenance, grow your own and pest control.

Garden Maintenance

Watering all plants is essential this month with extra attention given to containers that have limited capacity for water retention, new plants that are yet to become established and fruit and vegetables that will need to water as they’re producing fruits.
Water butts make a cost effective investment, especially if and when hosepipe bans occur.
  Aim to water early in the morning or in the evening when it’s cool to limit the water evaporating from the soil.

Keep topping up bird baths and bird feeders, remembering to keep them disinfected as often as possible to prevent the spread of diseases such as Trichomonosis (canker).

 Ponds will also need topping up with fresh water.

Camellias and rhododendrons need to watered thoroughly this month to make sure that the next year’s buds will develop well.

Feed flower beds and containers with a liquid feed every fortnight.

Weeds will continue to be a task to keep in mind. Try to keep on top of the weeds on a regular basis before they grow bigger and become harder to remove as well as more dominating of light, space and nutrients from the soil.

Summer flowering shrubs such as lavender will require pruning once the blooms are finished.

Remove the whippy side-shoots to about 20cm from their base on wisterias after their flowering period. 

Any top-heavy plants such as dahlias may require staking to prevent any wind and rain damage.

Collect ripe seeds on a dry day as soon as the seedhead has ripened. Collecting seeds from seedheads can be easier if the seedhead is dried in a greenhouse, warm windowsill or in an airing cupboard first.
  Seeds should then be stored in envelopes, marked with the plant variety and then stored in an airtight container. Adding some desiccant will remove the excess moisture which would otherwise lead to the seed deteriorating, rotting or dying from a fungal disease.

Herbaceous plants that have died back will need their foliage and stems cut back.

Repeat-flowering climbing or rambling roses can be left for another flush of flowers, otherwise they can be deadheaded for a tidy look, or left to go to hips for the birds later in the year.

Ground elder can be an issue in the garden, so while their leaves are large spray them with a glyphosate-based weedkiller. The large leaves will mean more surface to absorb the chemicals.

To prevent annuals and perennials from self-seeding and to encourage another wave of flowering into the autumn, deadhead as they start to go over.

Feed containers and perennial borders with a liquid tomato feed weekly. This will encourage flowering into early autumn.

By mowing meadows this month you will help to scatter any wildflower seeds.

Tender perennials such as pelargoniums and fuchsias can have cuttings taken now to propagate, ready to plant the following year.

By deadheading lilies as they fade you will be encouraging a better flower display next year.

Dividing clumps of bearded iris this month. This will give the plants enough time before the cold weather to form roots and flower bud for the following year.

If you’re away on holiday then it’s worth looking into ways of keeping your house and garden plants watered. This could be asking a friend of neighbour to water whilst you’re away or installing the wick method, utilising capillary matting in a similar way to the wick method and installing an irrigation system. A cooler room will help limit evaporation of water.

To encourage another flush of flowers, cut penstemon back to just above a leaf after their current flowers fade.

Hedges can take a little trim now. The cold weather later in the year will stop too much extra growth until the spring.

What to Sow

Sowing seeds isn’t a main focus for the month of August, but there are some plants which can be sown right now. It’s important to note that extreme heat can impact on the success rate of these sowings, so aim for a more ambient temperature when sowing and growing in August.

Start to sow winter-flowering pansies to enjoy into early spring and viola seeds that will over-winter for spring flowering.

Californian poppies, cornflowers and larkspur can be sown this month along with other hardy annuals for early flowers next summer.

Early-flowering perennials seeds can be sown now,  although the seeds will likely geminate after the winter. Examples of these perennials would be primroses, hellebores and aquilegias. 
You can help the germination process by adding in some vermiculite or perlite to the growing medium. This will help warm the soil later in the year.

Umbellifers such as Daucus carota (also known as wild carrot or Queen Anne’s Lace) can be sown directly into the ground. Choose a sunny, well-drained location.

Forget-me-nots can be sown throughout August and into September. They are a useful plant for ground cover and will easily self-seed.

Fruit and Veg

Winter lettuce can be sown in modules indoors or in a greenhouse towards the end of August.

Winter-hardy spring onions can be sown directly into the ground for spring crops.

Continue sowing salad leaves for a continual harvest and radishes also make for a quick crop, ready for autumn harvesting.

Pak Choi is prone to bolting if grown too early, so August is the ideal time to sow.

Fruit trees such as cherries, peaches, nectarines, plums and apricots will need to be harvested now.

Lemon and other citrus trees will require feeding throughout the summer. Visit our indoor plant department for the specific summer citrus feeds.

Winter cabbages can be planted out in early August. Remember to leave about 45cm between each plant as they do grow big.

To prevent against pests and diseases in the strawberry patch, tidy the space of old leaves and straw.

Sweetcorn, tomatoes, artichokes, cucumbers, selected potato varieties and aubergines should be ready for harvesting this month.

Before your main harvest for the frosts,  give your herbs a cut back to encourage a flush of new healthy leaves.

Towards the end of August early fruiting apple trees can be harvested.

Once you’ve harvested any fruited stems of blackcurrant bushes can be pruned. You can also do this for raspberries to allow space for the new green canes which will be the follow year’s fruiting canes.

Rooted strawberry runners and new strawberry plants can be planted outside now, giving enough time for the plants to establish before winter. Avoid planting in an area where you have grown strawberries previously within the last three years, to avoid diseases.

Prune restricted forms of apples and pears such as espalier, fans or pyramids to allow the sunlight to ripen the fruit. Pruning during the summer will also ensure good cropping the following year.
   The time to prune is when the bottom third of the new shoots are stiff and woody.
Cut back new shoots that are more than 20cm long, to three leaves above the basal cluster leaves.
Cut back new growth from existing sideshoots to one leaf above the basal cluster.
Do not cut new shoots that are less than 20cm long as they can terminate in fruit buds.
  Leave trees grown as standards or bush until winter to prune.

Cut back fruited raspberry canes on summer fruiting varieties to ground level without leaving a stub after harvesting in summer.
 Autumn fruiting varieties can have a number of their canes reduced now if overcrowded and remove any suckers growing away from rows.

 

 

 

 

 

 

 

 

 

Pests and diseases

Earwigs love late flowering plants such as gladiolus, chrysanthemum and dahlias. They will climb up the plant in the morning and eat the flowers during the day.

Codling moth caterpillars will be hatching early this month, and cause havoc as they eat the core of fruits. Codling moth traps hung in trees during June will attract and trap the males following the pheromones or alternatively apply glue or grease bands around the trunks of trees in early October that trap the flightless females as they climb down.

Adult viburnum beetles cause damage to leaves through August and into September. Unfortunately pesticides are more effective on the larvae than the adults, so treatments should be done in mid-April to May when the newly hatched larvae are feeding on the new foliage. The damage caused is not likely to affect the plant, but can be unsightly.
Avoid spraying plants that are in flower as to avoid harming pollinating insects.

Wasps, much like bees earn their place in the garden as they are great pollinators, eat aphids and feed caterpillars to their young. They can be a problem when growing soft fruit though, so hang a wasp trap in the trees.

Keep an eye out in the greenhouse for whitefly, red spider mites and grey mould. Keeping your greenhouse well ventilated and high in humidity will help reduce these problems. Hanging sticky tape is a good idea to catch any flying pests in the greenhouse too.