August in Your Garden

This quick checklist is to remind you what to do in August in your garden.

  1. Go for ‘Evka’…

Pelargonium peltatum ‘Evka’ is an ivy geranium with red single flowers and white edged foliage – a fantastic combination that makes this hybrid pop with attractive colour. It has a semi-trailing habit and is ideal for pots, baskets and borders. Flowering success with all types of pelargoniums relies on at least five hours of sun each day, water only when dry, and feeding as often as every two weeks, as these are hungry plants. August in your garden will be beautiful.

  1. Lawns need love now

For the lawn, the low cut, spiking and firm raking, levelling out, generous feeding, and covering with a nutritious blanket of organic lawn dressing is called ‘the spring treatment’ and is normally done in August, while September is still fine for colder areas. This treatment is not recommended for tuft-forming grasses like ‘All Season’s Evergreen’ or ‘Shade Over’ and should only be applied to runner-type lawns like kikuyu and some of the tougher cynodon grasses. Berea or Durban grass should just be mown as you would normally do, before following the rest of the steps for spring treatment.

  1. Pruning duties

Early spring is the perfect time to prune woody shrubs, especially foliage plants that are not influenced by a specific flowering season. They will regrow fast as the temperatures start rising. It is sometimes necessary to prune quite drastically, to knee height, in order to encourage new growth at ground level once again, cutting out ugly old bare branches below rather than allowing them to sprout new growth at eye level. So if some of your shrubs have grown into bare legged gnarly old bushes with just some growth at the top, bite the bullet now! Plants that can be pruned firmly include poinsettias, plumbagoes, tecomas, hypericums, heliotropes, solanums, canary creepers, golden showers and buddlejas that have done flowering.

  1. Plant a rose

‘Vesta’ is a strong-growing hybrid tea rose that falls into the new Stamina category of roses. This elegant bi-colour cream and coral-pink rose has a sweet scent. ‘Vesta’ grows into a 1m-high and 2m-wide bush, formed by strong spreading stems that curve upwards to form a huge canopy of disease-resistant leaves, from which large, well-shaped hybrid-tea style blooms are produced on medium-length, pickable stems. The leafy canopy ensures a deeply anchored, spreading root system that gives this plant stamina to withstand variable weather conditions and irregular rainfall. Group together and plant in a bed for maximum effect, although it is also suitable for a large container.

  1. Bedding besties

Winter seedlings that have finished flowering or need complementing with more colour can now be replaced or supplemented with spring and early summer annuals. Ring the changes with these suggestions:

Snapdragons – Antirrhinum majus ‘Snapshot Mixture’ is a dwarf collection of compact, upright and mounded annuals with full and fragrant flower spikes in a wide range of happy colours. They are perfect seedlings to plant up in large patches to supply colour throughout spring with a height of 15 – 25cm and a spread of 25 – 30cm. Plant in full sun and water moderately.

Foxgloves – If you love foxgloves but have a small garden try Digitalis purpurea ‘Dwarf Foxy Mixed’ (height 90cm). In this mix the upright and elegant flower spikes so loved by bees are a selection of pastel colours including cream, pink and rose. Foxgloves love rich, moist soil and full sun to partial shade.

Isotoma is a lovely annual of Australian origin belonging to the Campanula family. The lush green leaves have deeply serrated edges. Single flowers, each with five narrow petals, appear in spring. The plants are compact and rounded with a height of 30cm. Isotoma axillaris ‘Tristar’ is available in pink, white, blue and light blue, and should now be planted for a lovely spring show. They prefer full sun or light shade and rich well-draining soil.

  1. Carpets of flower power

Delosperma cooperi, also known as klipvygie or Coopers ice plant, is indigenous to South Africa, where it is mainly found in the drier parts of our country. It is a succulent, evergreen perennial that has a creeping habit. Plants have small, closely branched leaves that are round and up to 5.5cm long. The glistening quality of the leaves is due to water-containing cells on their surface that catch and reflect light, and give the name ‘ice plant’.

Delosperma cooperi loves the sun and thrives in dry and hot conditions. It is a vigorous spreader that forms a dense mat approximately 10 – 15cm in height, and spreads to a width of 60cm. They prefer to grow in well-drained soil – be aware of overwatering as this will cause plants to rot. Once they are established, these vygies are resistant to long periods of drought. If it is very dry, water well before their flowering time and you will be rewarded with a good show of blooms. The fuchsia-purple flowers have many slender petals radiating from the centre and are spectacular bursts of colour in the garden. Klipvygies have a lengthy flowering period from late winter extending right through spring. Once the flowers die down they are followed by highly conspicuous fruit capsules that insects love. Delospermas are hardy to frost and will grow in the winter-rainfall areas.

  1. Blooming nice!

The name of Aloe barberae (tree aloe) has changed to Aloidendron barberae, but when a specimen of this strikingly sculptural plant starts flowering in late winter, nobody cares about nomenclature – we see only the beauty. The flowers are salmon coloured and dripping with copious nectar that attracts scores of all kinds of wildlife. This large aloe, which can easily reach a height of 15 – 18m, forms a neat canopy of leaf rosettes. The smooth thin leaves arch away from each rosette creating a dramatic look. The bark is smooth and grey. Mature specimens are quite hardy and drought resistant, but will tolerate high rainfall as well. This aloe needs full sun, but light shade is fine too. It is a perfect choice to plant in roomy containers that will accommodate its large size without taking away from its natural beauty.

  1. Cuphea for bordering beauty

Cupheas (false heather) are very popular small shrubs with a neat, rounded growth habit, tiny leaves and masses of dainty little flowers for most of the year. Plants seldom grow taller than 30cm and can be clipped regularly to maintain a neat appearance. They are available in a range of different colours, with white, mauve and purple the most notable. Other hybrids are ‘Lemon Squash’ with pale lime foliage and lavender flowers, and ‘Cocktail’, which has rich golden foliage and contrasting purple flowers. All of them succeed in full sun and light shade and require very little attention except for protection from frost in the colder regions. Cupheas also make wonderful edging plants when clipped into low, boxed hedges approximately 20 – 30cm high.

  1. For indoors and outdoors

Nothing beats the grace of ferns, whether in a garden, on the patio or indoors. We planted ‘Green Ripple’ to introduce you to a must-have variety of our very own indigenous Asparagus densiflorus. The dark green foliage is loosely compacted, fine needled, and spills over pots or garden beds. This is a lovely feature plant for containers and garden beds as a specimen plant or for use in mass planting. It is a hybrid between Asparagus densiflorus ‘Meyersii’ (cat’s tail) and Asparagus densiflorus ‘Sprengeri’ (basket asparagus), which give it the attributes of a loose cat’s tail fern. The leaves may get damaged by frost but will re-emerge in spring. It is excellent for flower arranging. Expose it to full sun or semi-shade in the garden and in high-light areas indoors. Dimensions are 1m x 1.2m.

  1. Let’s divide the guzmanias

Guzmanias are bromeliads that produce vibrant star-shaped flowers in a wide range of colours. They are popular houseplants to display in bright, natural light. There are two sides to the cultivation of these epiphytes – the mother plant will die after flowering, at the same time producing quite a few pups that can be removed and divided up to create more plants. Cut off the old flower stalk, remove the plant from its container, and gently separate the pups from each other with sharp scissors. Then replant them in separate pots filled with commercial orchid mixture.


  • Fill the central well from which the new flower stalk will arise about ¼ – ½ full of water, which should be flushed out and replaced regularly with fresh water to prevent bacterial build up.
  • Mist spray the plants regularly in hot weather for extra humidity, and also moisten the soil in the pots now and again.
  • Very light fertilising can be done by spraying it on the leaves of the plant once or twice a year. As guzmanias are epiphytic they take up their nourishment through their leaves.
  1. Cut flowers galore

Chamelaucium, commonly known as the geralton wax flower, is a great shrub to add to your garden. Spectacular masses of flowers cover the entire bush from July – September and last for weeks as long-stemmed sprays of cut flowers in the vase. The leaves are highly aromatic when crushed and the plant are tough and drought tolerant when well established. Wonderful new hybrids are available now.

  • Perfect coastal plant – wind resistant.
  • Good for screening – Height about 2m or more.
  • Light frost resistant.
  • Loves sandy or rocky soil.
  1. Feeding is the priority now

  • Feed spring-flowering bulbs with specialised bulb food.
  • Feed hydrangeas with specialised fertiliser for blue or pink flowers.
  • Supply a fresh layer of compost to all beds, feed with a general slow-release fertiliser, water well and apply a final layer of mulch.
  • Feed tropical fruit trees.
  • Feed roses after pruning.
  • Feed acid-loving plants like azaleas, gardenias, and brunfelsias with a microelement mixture to correct yellowing leaves, and mulch with pine needles or pine bark.
  1. Pests and problems

Snails and slugs will give it their best shot to feast on all your soft new spring plantings. Do battle with them by putting out snail bait, but also plant barrier plants like mint, garlic, chives, geraniums, foxgloves and fennel, which these pests hate, around susceptible plants.

  1. Start planting summer bulbs

In late August you can start planting all the beautiful summer-flowering bulbs like gladiolus, calla lilies, dahlias, cannas, spider lilies, George lilies, tuberoses, galtonias, schizostylis, liatris, crocosmias, eucomis, and storm lilies.

  1. Quick checklist

  • Don’t be in a hurry to remove the frost covering on frost-sensitive plants.
  • If you want to cultivate grapes in your garden, it is now, in the colder months, that you need to purchase and plant your vine stocks.
  • Divide overgrown flaxes, ornamental grasses, agapanthus and daylilies.
  • Fruit trees will enjoy a mulch of kraal manure and an application of 8:1:5 fertiliser.
  • Don’t be tempted to prune frost-damaged plants even if they look sad, just yet. Pruning now will encourage soft new growth that will be killed off by late frost.
  • Safeguard your garden against damage by the August winds by tying down all the susceptible plants like standard roses and young trees.
The Gardener