10 must-dos this month
Contributing garden editor Marianne Alexander’s handy checklist of essential chores to do in August
Liven up dull gardens with six packs of spring-flowering bedding plants like primulas, pansies, calendulas, dianthus and snapdragons. Maintain your feeding regimen and deadhead to ensure a longer, better display.
Start looking for summer bulbs to plant in September. Indigenous options include gladioli, red-hot pokers, arum lilies, scadoxus, crocosmia and cyrtanthus. Exotic bulbs include tiger lilies ( Tigridia pavonia), chlidanthus and liatris.
Mulch the whole garden. Organic mulches improve the soil and feed plants. Try mushroom compost, dry lawn clippings, shredded bark or bark chips, nut shells and straw bales. A 30m³ bag of commerical compost spread 5cm deep will cover about 2m². Mulch acid-loving plants with old teabags, pine needles, bark chips and oak leaves. Keep feeding spring bulbs until the leaves have withered. Use 3:1:5 or 2:3:4 or a high-potash food for healthy flowers next year. You can also use fresh wood ash. Scarify kikuyu and buffalo lawns where runners have built up a thick thatch. Rake to loosen the dry grass, or mow on a low setting then again at a 90° angle.
Check if dormant summer-flowering plants like achimenes, hippeastrums, tuberous begonias and gloxinia are shooting. If not, provide more light and water. Remove scale and mealy bug from ferns, palms and other indoor plants with a cotton bud dipped in diluted methylated spirits. Give winter-flowering indoor plants like cyclamen less water to encourage dormancy, and repot summer bloomers that aren’t performing. Finish pruning hydrangeas, mulch and start feeding. Apply 2T of blueing agent, aluminium sulphate, fortnightly. Pinch out the tips of fuchsias. Prune roses in the subtropics. Cut back summer and autumn-flowering salvia by two thirds in warm areas. Check that ties on staked plants aren’t strangling their stems.
Deal with weeds as soon as they appear. Remove from lawns by hand or spot treat with a suitable herbicide and smother those in beds and borders with thick mulch. For organic weed removal on driveways and paths, pour over boiling water or vinegar or sprinkle with salt.
Revitalise the soil around roses in mid to late August. Lightly fork in the old mulch, add a sprinkle of bonemeal, compost, old manure and a few handfuls of Epsom salts (magnesium sulphate). Water and apply 5–10cm mulch: pine bark, peach pips, peanut husks or straw. Give each plant about 30g of a fertiliser like Vigorosa 5:1:5 or Talborne Vita-Green 5:1:5.
Boost azaleas, rhododendrons and camellias by watering in a light application of high-nitrogen fertiliser. Apply iron chelate to acid-loving plants like yesterday-today-and-tomorrow, gardenias and citrus trees with yellowing leaves; follow up a few weeks later with Epsom salts.