August - the unpredictable gardening month!

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Image by Pezibear from PixabayImage by Pezibear from PixabayAugust is known as the “windy month” in South Africa, and throughout the country August is also said to be the most unpredictable. Read more below on how to get to most out of your garden in August.

In the temperate or Highveld summer rainfall regions, as well as those dry, semi-arid and continental regions of South Africa, August can produce many warm sunny days followed by sudden, late frosts. In the winter rainfall regions it can be sodden, and the northwest winds may still be howling; and even in the subtropical summer rainfall regions, August can still be very unpredictable, but take heart because spring is on the way.

Image by Brigitte makes custom works from your Photos thanks a lot from PixabayImage by Brigitte makes custom works from your Photos thanks a lot from PixabayFirstly, don’t be in a hurry to remove your frost covers until you are sure that all late frosts are over, and ensure that all your standard plants and young trees are securely staked. When planting large trees or shrubs it may be essential to stake them, and newly planted fruit trees and standard plants like roses should always be securely staked until they are well established. To ensure success familiarise yourself with the various methods of staking before planting. Click here to read my free article on staking.  

To keep your winter and spring annuals blooming, remove the spent blooms regularly,  and continue to feed and water regularly.  The more you pick sweet peas and Iceland poppies the more they bloom, so pick them often to brighten up your home and office.

In the subtropical summer rainfall regions you can sow or plant alyssum, asters, cleome, New Guinea impatiens, salvia, cosmos, verbena, marigolddianthus and bedding begonias. Cuttings of bedding begonias, coleussalvia and New Guinea Impatiens will take root quickly as the weather warms up.

In these regions you can still make sowings of quick maturing winter veggies like oriental vegetables and lettuce; and you should get one last sowing of carrots. Plant out  sweet potatoes, green beans, pumpkin and squash like patty pansbeetroot, baby marrow, eggplant, cucumber, maize and sweetcorn, melons, peppers and tomatoes, radishrhubarb, and Swiss chard.

In the winter rainfall regions, as soon as the soil dries out enough, prepare your beds for sowing and planting out summer flowering annuals. Click here to find more articles and lists of summer flowering plants. 

'Cherry' Tomatoes 'Cherry' Tomatoes In the summer rainfall, temperate or Highveld regions, and the dry, semi-arid and continental regions, if you have a seed germinator tray, or a warm, protected place, you can start sowing early summer vegetables as well as summer flowers into trays; if you don’t have a protected place wait until September because summer seeds can only be sown directly into garden beds when all danger of frost is over and the soil temperatures are warm. Click here to find more articles and lists of summer flowering plants. 

Mulching the ground after planting out flower or vegetable seedlings, and grouping them together in the garden according to their watering requirements, will save you a lot on water bills.

Summer bulbs like gladioli, amaryllis, arum lilies, tuberous begonias, canna cultivars, dahlia, pineapple flower (Eucomis), berg lily (Galtonia), spider lily (Hymenocallis), gayfeather (Liatrus), liliums, Tigridia and tuberose start arriving in the stores in August; buy them as soon as they are available to avoid disappointment, and store them in a cool place until planting time in September.

Be warned however, moles love bulbs, and especially amaryllis bulbs; so if you have a mole problem plant them into special pots available in garden centres, or make a basket in the soil with chicken mesh; leaving about 3cm of mesh above the ground to stop the moles from going over the top.

(Highlighted plants are included in our Plant Index and members can click on the links for more information on the plants mentioned)

Frost bitten evergreen shrubs can be pruned in August or September, when there is no longer a danger of late frosts; and when you do prune, remove all green branches from variegated shrubs right at their base, or the stronger growing green shoots will quickly overtake the variegated ones.

In the winter rainfall regions overcrowded groundcovers and perennial plants are generally divided in autumn before the winter rains arrive, but in cold and frosty regions, this is only done when the late frosts are over. Gently pull apart the actively growing plants from the outside of the clump, choosing only healthy looking pieces and discarding the woody central part of the mother plant, and  transplant immediately into well-prepared beds. Mulch the clumps with compost or manure and feed with organic 3:1:5 or 2:3:2 fertilisers; watering it in thoroughly afterwards.

If your ornamental grasses are looking untidy but do not need dividing, just as they start shooting again, prune them back right down to the ground, mulch, feed and water well.

Members can click here to read my full regional gardening article on what to do in the garden in August, in my ‘Gardening Month by Month’ section. 

New PotatoesNew PotatoesSeed potatoes are planted out in August and September for harvesting in December. New potatoes are harvested much earlier. If space is limited, grow them in potato sacks or dustbins. 

Try your hand at growing sweet potatoes this summer, they grow like weeds. Read my free article on growing them here.

Peas, including sugar snap peas thrive in cooler weather, but although the plants are frost hardy the flowers aren’t, so in very cold regions they are generally planted in July or August to ensure that they flower once all danger of frost is past. Seeds can be planted directly into the garden or into containers - low-growing varieties that don't require staking are ideal for containers and small vegetable gardens. Seedlings germinate within a week or two and grow quickly, so in 2 to 3 months you will be able to start harvesting.

In frost-free regions you can continue to sow vegetables, but in those parts of the country which still experience low night temperatures and frost in August, it is better to wait until next month before sowing or planting out summer vegetable seedlings, and unless you have heated germination trays, tropical vegetables, like eggplants, tomatoes and peppers will not germinate unless the soil temperature is sufficiently high. In these regions plan your summer vegetable patch, and prepare the beds now for planting or sowing in September.

A beautiful lawn needs regular care throughout the year but especially in spring and summer, so if you want a gorgeous lawn this summer read the guidelines below and start preparing now.

In warm, frost-free regions you can prepare your lawn in August, but in colder regions it is better to wait until September when all danger of frost is over. In the winter rainfall regions lawns are traditionally scarified and top-dressed in autumn but once the soil dries out a bit you can top dress lightly and fertilise with an organic lawn fertiliser that is high in nitrogen.

Image by Klaus Neumann from PixabayImage by Klaus Neumann from PixabayEarly spring and summer are also perfect times to sow all types of lawn seed, and if you have a small garden you should consider sowing an evergreen lawn. Evergreen mixes are available for both sun and shade, and because they do not creep, they will not invade your garden beds. They are also hardy, and as long as they can be watered regularly, will grow well throughout the country; with the exception of very humid regions.

Prepare the beds in August so they are ready to sow evergreen mixes as soon as all frost is over. Dig the bed over to a depth of about 20cm and add lots of compost and a dressing of 2:3:2. Rake the bed smooth and water gently. Once the temperatures are right, you can sow the seeds as recommended, rake the bed lightly once again after sowing and water well. Ensure that the soil remains moist but not soggy until all the seeds have germinated, and allow the grass to establish itself well before mowing it for the first time. Please note that these evergreen mixes cannot be cut as short as kikuyu, so read all the sowing and care instructions on the seed box before sowing.

Established runner lawns like Kikuyu should be mowed extremely short in early spring, once all danger of frost is over. They should then be scarified with a hard rake or broom to remove the dead mat (use the rakings to mulch your garden beds or add them to the compost heap). Spike the entire area with a lawn-spike or do it manually using a garden fork, driving it into the soil about every 30cm. After scarifying and spiking, water thoroughly, and the following day, apply agricultural lime at +-200g per square meter, watering it in well. About a week later, feed with a good organic fertiliser like Blade Runner, watering it in well.

Because the agricultural lime improves the uptake of the nutrients applied, your grass will grow so vigorously that most aggressive emerging weeds will be smothered before they have a chance to establish themselves and set seed. Those that do push through must be weeded out immediately. For a perfect lawn all summer it is essential to feed every 4 to 6 weeks, and to mow and water regularly. Remove any weeds and as soon as they appear, and before they set seed.

Please note that the above scarifying procedure only applies to runner-type lawns like Kikuyu, and will damage tuft forming grass varieties like shade lawn and evergreen mixes.

Kentucky Blue, and subtropical grasses like Berea, which is also called LM or Durban grass can be spiked and dressed but should not be cut too short.

Established areas of tuft forming grass varieties like shade or evergreen lawn mixes can be very lightly mowed and then lightly dressed and any hollows evened out with a good weed-free lawn dressing. Adding some bone meal to the lawn dressing will give your lawn an extra boost, and if there are any bare patches, seed can be added to the dressing. Water thoroughly and regularly thereafter until your lawn is well established.

Rose Hips Image by Couleur from PixabayRose Hips Image by Couleur from PixabayThere's still time to prune and to plant out new roses. In most temperate parts of the country July is traditionally the time to prune and to plant out new roses, but you can still safely prune now if you get it done quickly before new growth begins in earnest. Delaying for another week or two is not detrimental but will result in your roses flowering later than normal. In the winter rainfall regions pruning starts from the end of July to August; and in warm subtropical regions you can prune from June to early August.

In very cold regions pruning is usually delayed until the middle of August, and if your un-pruned roses start shooting as a result of unusually warm weather, do not panic, because these shoots are usually on the tips of the branches, and will be pruned off later anyway, so it is not a problem, and the dormant shoots below will still shoot timeously in spring. If, however, you notice signs of red spider on the leaves and shoots, prune them off immediately to prevent serious infestations of the summer foliage.

Click here to read my article "Easy guidelines for pruning roses" 

When your pruned roses start showing signs of shooting give them a deep soaking and then water deeply every week, and as the weather warms up towards the end of the month you can increase your watering to about twice weekly. Mulch the roots of your established plants with mature kraal manure or compost; keeping it well away from the stems to avoid collar rot. Feed with an organic fertiliser that is high in nitrogen like 8:1:6 and water thoroughly. To prevent early insect infestations spray your plants with an organic insecticide when the new leaves emerge. It should not be necessary to spray against fungal diseases this early in the season; unless you live in subtropical regions.

Peach tree blossoms. Image by anadfontana from PixabayPeach tree blossoms. Image by anadfontana from PixabayDeciduous fruit trees like peaches will be coming into bloom this month, and you need to be spraying against fruit fly etc. To be most effective sprays must be applied at specific stages of crop development, and the terms used to describe the stages of fruit development in peaches and plums are: Dormant: Late autumn to early spring; Bud break: Buds begin to swell; Bud swell: Buds are noticeably swollen, but no green tissue is present; Pink: Just before the flower buds open; Bloom: flowers open; Petal fall: Last petals are falling; Shuck-split: Most of the developing fruits have split away from the remains of the dried flower.

Click here to read my free article on growing peaches and nectarines, where you will find an in depth spraying programme for deciduous fruit trees.

Fruit flies emerge in early summer, so you need to start spraying, putting out fruit fly bait stations, or both, every two weeks throughout spring; at bud break, pink, and at petal fall. This is especially important if the weather remains warm and sunny.

Gardeners can monitor fruit fly by using fruit fly traps, and commercial pheromone traps are available at cooperatives. Pheromones are chemical compounds that are produced and secreted and that influence the behaviour and development of other members of the same species. Chemical control pesticides registered specifically for baiting stations are available at garden centres.

An environmentally friendly product by Efekto: Eco Fruit Fly Bait GF-120 is excellent for baiting stations. It consists of a plant protein and sugar formulation with Spinosad as the active ingredient. Spinosad is derived from a soil organism, making GF-120 one of the safest pesticide products available.

Various sprays are also available for fruit fly like Biogrow, Bioneem. Its active ingredient is Azadirachtin from neem seeds and it is used to control a wide range of insects (up to 200 insect types) including white flies, leaf miners, mealybug, thrips, fruit flies, leaf hopper, red spider mite, weevils and many more. It is relatively harmless to insects that pollinate crops and trees, such as butterflies, spiders and bees; ladybugs that consume aphids; and wasps that act as a parasite on various crop pests. This is because neem products must be ingested to be effective. Thus, insects that feed on plant tissue succumb, while those that feed on nectar or other insects rarely contact significant concentrations of neem products.

You may even like to make your own fruit fly baiting station and there are many recipes online, but a very simple trap can be made by pouring apple cider vinegar in a bowl and covering it with cling film. Pierce several small holes through the cling film to allow the smell to escape and the fruit flies to enter. Fruit flies don’t seem to be able to resist the aroma of the cider vinegar and then they get trapped in the bowl and can’t find their way out. Change the vinegar regularly to keep its efficacy and watch the fruit flies flock to it.

Image by sevenpixx from PixabayImage by sevenpixx from PixabayAs the weather warms up you will need to water your garden more frequently, and miraculously the weeds appear, so remove them immediately and before they get a chance to set seed. Mulching the soil not only conserves water but also helps to smother emerging weeds; so if you have not mulched your beds yet do so without delay.

Preparing in August to plant in September will get your garden off to an early summer start, which is essential if your wish to get the most 'bang for your buck' when planting flowering annuals, veggies, herbs, and of course, summer bulbs.  

I hope you found this condensed version on what to do in your garden in August helpful. Click here to find information on what to do in your garden every month of the year.