September is here – the sun is getting warmer, and our gardens are showing new signs of life. Spring is the perfect time to look at your garden with fresh eyes, make some changes and plan for the summer months ahead.
The 1st to the 7th of September is national Arbor week in South Africa - a time when South Africans of all ages are encouraged to celebrate the beauty and importance of trees.
The trees of the year for 2019 are Common Tree of The Year: Sclerocarya birrea Marula Maroela. Rare (Uncommon) Tree of The Year: Philenoptera violacea Apple-leaf, Appelblaar.
The month of September is the perfect time to plant an indigenous tree in your gardens - at home, office parks, and schools – especially as we are currently losing many of our trees to the invasive Shothole Borer.
What to Sow
During summer months, having fresh salad supplies ready to pick from your garden is a win! September is the time to sow lettuce, spring onion and tomato seeds, ready for your summer salads.
- Lettuce can be grown in a sunny garden bed. Most varieties are quick and easy to grow and produce a harvest within a month or two. The loose-leafed varieties are the most practical because you can harvest the individual leaves for up to three months before replanting. Others, like the butterhead or iceberg, are picked when the heads form, so it’s best to sow seed at 3–4 weekly intervals to have a constant supply. Use a fertile, well-draining soil medium and space about 30cm apart to allow for good air circulation. Keep the soil evenly moist at all times — drought stress can cause a bitter taste.
- Spring Onion can be grown in sun or partial shade and prefer rich soil with compost dug in. Space seeds 10cm apart.
What to Plant
A perfect plant to fill your shaded gardens with bright, long-lasting colour in summer is Impatients. The new Beacon Impatiens (Impatiens walleriana) offers high resistance to downy mildew and won’t collapse due to this destructive disease. For lasting colour plant your Impatients in fertile, well-drained soil in shade or partial sun. Beacon Impatiens are also great for baskets, window boxes, and containers, but will need a steady supply of water.
What to Spray
You know that spring has arrived when you smell the Jasmine and see the orange blaze as the indigenous Clivia’s start to emerge from their buds. Watch out for the lily borer in your Clivia’s. The caterpillar and their larvae damage the stems and leaves and if left untreated will cause a lot of damage. If you see any traces of larvae or damage to the plant, apply contact insecticide every two weeks to control.
What to Feed
Rejuvenate your lawn in September by applying a lawn dressing - a mixture of well-balanced organic matter and weed-free soil. A thin layer should be spread on established lawns to level an uneven surface or help a lawn recover after an icy winter. It would help if you also replenished nutrients by adding a nitrogen-rich fertiliser. Chat to the friendly experts at your nearest GCA Garden Centre for the best products to use.
What to Prune
Maintenance is the heart of gardening, and September is an excellent time to get in there with some pinching, deadheading, and pruning. Your flower garden will be healthier and lusher and will stay in bloom throughout the season. Most flowers benefit from having their spent flowers removed. This is called deadheading. Flowers that repeat-bloom will often do so only if the old, dying flowers are removed. If the dead flowers remain on the plant, they will go to seed, and the plant will stop producing flowers.
Some plants have very crisp, thin stems and can be deadheaded using your fingers. This type of deadheading is called pinching. Some plants that can be pinched include daylilies, salvia, and coleus. Coleus are grown for their foliage, not their flowers. Pinching off the flowers encourages the plants to become bushier and fuller.
From the middle of September, you should pinch prune your Hybrid Tea roses. This encourages new basal growth, green leaves and root development. It spreads out the flowering cycle so that there is an almost continual supply of roses instead of one or two main flushes. Pinch –prune about a third of the shoots. Increase watering to at least twice a week and fertilise fortnightly.
Watch out for aphids, thrips, bollworm and powdery mildew. To be effective, the spraying of roses for the control of pests and diseases needs to be carried out properly and with the correct understanding of both the pest and the applicable pesticides. One does get a canola oil, based pesticide combined with a systemic action fungicide which is a certified organic option. Visit your local GCA Garden Centre for advice on the best products to use to meet your needs.
(Gauteng, Free State, Northern Cape, North West, Mpumalanga and Limpopo)
With the rainy season upon us, ensure that your rainwater harvesting systems are set up and connected correctly. Clean out your gutters to ensure proper water run-off and to make sure your collected rainwater is as clean as possible.
Get your summer herb garden planted with these easy to grow summer herbs:
Thyme, rosemary, marjoram, oregano, basil, rocket, parsley and mint. Buy your seedlings from a Garden Centre GCA renowned for quality plants and frequent deliveries of fresh stock.
Weed regularly before it gets out of hand. Treat weeds on paving, pathways and in gravelled areas with a non-selective herbicide. Visit a GCA Garden Centre for advice on the best products to use.
Plant your summer-flowering bulbs
Arum Lilies and Calla Lilies (Coloured Zantedeschia hybrids)- plant your Zantedeschia bulbs at the beginning of spring, around 4 - 5cm’s deep. Space bulbs 30 to 40 cm apart, because Zantedeschia has wide-reaching leaves and needs space. Choose a location that is in full sun but stays cool. Don’t plant in very dry soil.
Dahlias (Dahlia pinnata). 2019 is the Year of the Dahlia! These colourful, spiky, daisy-like flowers bloom from midsummer right through the first frost. Select a planting site with full sun as they will blooms more with 6 to 8 hours of direct sunlight. They love the morning sunlight best. Choose a location with a bit of protection from the wind. Dahlias thrive in rich, well-drained slightly acidic soil.
(Western Cape, Eastern Cape, and KwaZulu-Natal)
September is a great time to refresh, top-up or replace pebbles and gravel around the garden - especially between paving stones where dust and mud have accumulated.
Check for algae and moss on paving. Scrub down with a solution of copper sulphate or use a moss killer.
Create a pretty spring border with the following indigenous flowering plants: Gazanias, Arctotis, Blue Felicias, Scabiosas and Cape daisies.
Buy your seedlings from your local GCA Garden Centre.
Now is an excellent time to prune your Hibiscus, Poinsettia and other winter-flowering shrubs. Pruning your Hibiscus will help stimulate budding on new shoots. It also rejuvenates the plant after their long winter nap while encouraging them to maintain an attractive appearance and healthy, vigorous growth. The flowers of the Poinsettia have actually modified leaf structures called bracts. Once these have wilted and begun to die off, the Poinsettia requires a thorough pruning. Poinsettias may also require some trimming throughout the growing season to remain full and healthy.
Plant these Beauties to add some colour
Gerbera daisies (Gerbera jamesonii) are commonly grown for their bright and cheerful daisy-like flowers. They are indigenous to South Africa and come in various sizes and colours including pink, yellow, salmon, orange and white. Gerberas are best planted as seedlings, rather than seeds. This is because the flower resulting from seed may not reflect the colour expected and take far longer to flower. They prefer full sun with relatively sandy soils that are well-drained. None of the stems should be planted under the soil as it will rot, and the plant will die. Do not water them too often, as the soil should not become saturated. They can be grown in pots or containers too. They do well in the heat but do not handle the cold well.
Gladioli bulbs (Gladiolus species) come in a fantastic range of sizes, forms and colours, even lilacs and blues. It is a classic perennial known for its tall flower spikes. A great cutting flower, gladioli look beautiful in midsummer bouquets. Plant Gladioli bulbs in the spring once the danger of frost has passed and the soil has warmed. Most Gladioli thrive in well-composted, well-drained loose, sandy to light loamy soils. A sunny position is best. The taller varieties, which should be staked, are often placed in the back of a garden to complement shorter plants nicely.