September in the Garden

Spring is here! The quote “We’re so excited, we wet our plants!” is really appropriate to how we feel right now! 🙂 Time to create a rainbow of early spring colour with lots of exciting plants which are in flower now, and to start working on your summer veggie harvest.  

Trees for Africa!

National Arbor Week is from 1 – 7 September which gives you seven official days to plant trees. The following are recommended by GCA nurseries:      

Buffalo Thorn (Ziziphus mucronata) – this is an attractive, small to medium size deciduous tree, reaching up to 9m in height and is the official tree of the year for 2017. It produces a fairly dense spreading canopy. The young trees have sharp, paired and dissimilar thorns, one being straight and the other hooked. The flowers and fruit of these trees are sought out by birds and bees. This pleasing little shade tree withstands drought, is moderately frost resistant, and succeeds in most soils and conditions.

Pomegranate ‘Wonderful’ (Punica granatum) is a leading cultivar with a resistance to adverse conditions and a high yield potential of huge blush red fruits. It is a small deciduous tree (2,5 m high), for climates with cool winters and hot summers.

Olive varieties – these hardy, but beautiful trees with their dull green leaves with the silver reverse, can tolerate very cold (and hot) temperatures and wind. Good varieties are ‘Manzanilla’ and ‘Mission’. Olive trees are not only functional, but become really pretty shade trees that blend well within any planting scheme or garden design.

Lilies to please!

As 6 September 2017 is officially ‘Secretary’s Day’ visit your local GCA nursery for potted calla lilies (Zantedeschia) which will be in magnificent flower, to present with love to your faithful ‘slave’ in the office.

Then, choose between the wide selection of exotic colours available in the range of arum rhizomes which just have to be planted in the garden in spring. Bright pinks, royal purple, deep maroon, sparkling orange and even the flashiest two-tone shades are not unusual. Success with calla lilies (arums) relies on rich, well-drained, but just moist soil, full sun, deep watering about twice a week, and regular feeding with bulb food.

Smart planting

September bush (Polygala myrtifolia) covers itself with blue to purple flowers in spring. This fast-growing indigenous shrub grows up to 2m high and 2m wide and is semi-hardy to cold and frost. Plant in full sun to light shade. If you want the same pop of power, but in a more petite size (50cm x 40cm), go for Polygala fruticosa ‘Sugar Baby’ – similar characteristics, but in daintier form.

Lampranthus – Other wise known as vygies. Amongst the many species with upright or trailing growth habits, there is a colour range which includes white, cream, pink, salmon, red, yellow, mauve and purple. Smother your dry zones or rock garden with vygies – few other plants can beat their brightness and economical water usage!  

Clivias for you! One is reassured that winter is finally over and that spring has arrived when the vivid orange blooms of clivias appear. These evergreen shade-loving plants with their glossy strap-like leaves and huge flower heads will liven up the dullest shady corner if planted en masse. They are equally impressive in large containers on a shady patio.

Sunny side up with Marigolds  

Marigolds might not be regarded as glamorous by some, but they are undisputed midsummer performers. No other annual delivers such a blaze of yellow and gold, while looking fresh and vigorous during the hottest months of the year. Marigolds range in height from tall cut flower varieties, to dwarf edging and border marigolds with medium-high cultivars in-between for beds and mixed borders. Their flower shapes and sizes also vary and all GCA nurseries will carry the whole range of seedlings for you to plant. These annuals do not like to be overwatered or to grow in shade.

New in-store for September

The sunflower has inspired master painters like Vincent Van Gogh, is liked by birds, and has become a world-wide commercial crop for oil production. But, is has also stolen the heart of cut flower gardeners since the earliest ages. New sunflower varieties to look forward to, include:

– ‘Vincent’s’ with an extra ring of rounded, overlapping petals for better filled, more attractive flower heads and flowers which face upwards on strong stems and necks.

– ‘Miss Sunshine’ is a dwarf, golden yellow sunflower which produce 7 – 10cm blooms with a fast flush of secondary flowers.

– Also look out for ‘Dwarf Sunspot’ and ‘Tall Yellow’.

Rose care for September

Fine tune roses for a spectacular flower flush next month. Pinch-prune about a third of the shoots, start increasing watering to at least twice a week. Fertilise again at the end of the month and spray fortnightly against pests and disease.

Compost and feed all

Remove weeds (they compete for moisture in established garden beds), build up the soil with lots of organic matter like compost, feed with a slow release fertiliser, then water, and add a final layer of mulch. Commercial mulches in store include coarse compost, composted bark, peanut or other nut shells, crushed peach pips, wood chips, pebbles and stone.

Pest control

Powdery mildew needs to be treated preventatively with a fungicide. Once there, it can only be controlled so as not to spread further. If the fungal infection is serious, remove all infected plant parts and destroy them. Do not compost any infected plant parts.

Eradicate sucking insects such as aphids by a seasonal soil drench with a systemic insecticide.

Care for lawns

Train your lawn to be water wise by watering it well only once a week – this will encourage deeper root growth. Never mow too short as this keeps the roots near the surface where they are more likely to dry out. If weeds are a problem in large lawn areas, treat with a broadleaf herbicide. For smaller lawns, use a convenient ready-to-use broadleaf herbicide.

Commercial lawn dressing is perfect for levelling and smoothing out a lawn, and to encourage new growth. Use a quality product from a reputable supplier, as it will contain sterilised, finely sieved organic materials which will improve drainage and water holding capacity. Apply it no thicker than a 3cm layer to a fairly dried off lawn. Level it out by means of a flat board tied to the end of your rake.

Gardening in small doses

Balconies and containers allow one to garden really intensely in small spaces.

  • Fill pots with bright, spring-flowering azaleas.
  • Paint old pots in colourful shades and plant them up with annuals like lobelias and dianthus and sweet Williams.
  • Fill your worn out gum boots with all kinds of pretty succulents.
  • Vertical gardening on a patio is a lot of fun – recycle old wooden pallets, or planks, and fill them with succulents, herbs, or colourful annuals.

Sow with savvy

Do not go overboard when you start sowing your summer veggies. Here is a quick guideline to ensure a sustainable harvest:

Leafy veggies: Sow these in every two weeks.

Root veggies: Sow four weeks apart.

Legumes like beans: Sow every three weeks.  

Fruit-bearing veggies: Sow between six and twelve weeks apart.

Feed young seedlings every two weeks with a water soluble fertiliser at half strength. Keep an eye out for aphids and combat with an organic insecticide.

Inland gardening

(Gauteng, Free State, North West, Mpumalanga and Limpopo)

  • If you’ve been dreaming about a new herb garden and have already prepared the soil or pots, go out now and buy the plants. Visit your local GCA garden centre; they are renowned for quality plants and frequent deliveries of fresh stock. Recommended and easy to grow summer herbs include thyme, rosemary, marjoram, oregano, basil, rocket, parsley and mint.
  • Iceland poppies should be picked when they are in bud. They will open indoors. Cut-flowers with milky latex, like Iceland poppies, should be held under the flame of a candle for a short while before they are arranged. This stops the latex from leaking and blocking the stems.
  • Start planting begonias and impatiens in the shade and Sunpatiens in the sun.
  • As soon as the winter and spring flowering shrubs like Cape Mayflower have finished flowering, prune them back. This simple rule allows the longest possible re-growth time before the next flowering season.
  • If you do not have a good garden hose sprayer, invest in one. A reputable brand is the best choice. Hose sprayers with gun nozzles that shut off automatically, save a lot of water and reduce wastage.
  • Start spraying fruit trees against fruit fly and codling moth once about 75% of the blossoms have dropped off. Spray every 10 – 14 days with fruit fly bait
  • Plant seed potatoes in trenches of about 10 to 12cm deep, which are filled and earthed up while the tubers are growing. 

Coastal gardening

(Western Cape, Northern Cape, Eastern Cape, and KwaZulu-Natal)

  • Plant sweet potatoes and seedlings of green peppers, eggplants and parsley. Sow cucumbers.
  • Prune hibiscus and poinsettia, and other winter-flowering shrubs.
  • Plant gerberas and gladioli bulbs.
  • Create a pretty spring border with the following indigenous flowering plants: gazanias, arctotis, blue felicias, scabiosas, and Plectranthus ‘Mona Lavender’.
  • Start planting dahlia tubers. The flowers, which are available in most colours except blue, vary in size from miniatures of less than 2cm in diameter to huge, soup plate sizes.
  • Spring-flowering annuals should be deadheaded on a continuous basis in order to prolong their flowering season.
  • Plant a row of young Cupressus macrocarpa ‘Gold Crest’ for that gorgeous green and gold flush. Stake their main stems well and straight, and keep on removing all the side growth from the bottom two thirds of the plant. As soon as a height of about 1,2m is reached, you can start shaping the top growth into balls. You will soon have your own golden-yellow lollypops.
  • Refresh, top-up or replace pebbles and gravel around the garden. Especially between paving stones where dust and mud accumulate to spoil the effect.
  • Check for algae and moss on paving. Scrub down with a solution of copper sulphate or use a moss killer.
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