It’s spring, the perfect time to look at your garden with fresh eyes and make changes. Here’s what to do in your garden in September…
In celebration of National Arbor Week (1 – 7 September), consider where you could plant a tree or two in your garden.
The trees of the year for 2019 are: Sclerocarya birrea Marula Maroela (the Common Tree of The Year) and Philenoptera violacea Apple-leaf, Appelblaar (Rare/Uncommon Tree of The Year).
September is the perfect time to plant an indigenous tree in gardens – whether that’s at home, in your office park or your kids’ schools – especially as we are currently losing many of our trees to the invasive Shothole Borer.
In the vegetable patch
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 lettuce, are picked when the heads form, so it’s best to sow seed at three to four 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 prefers a rich soil with compost dug in. Space seeds 10cm apart.
In garden beds: What to plant for colour
A perfect plant to fill your shaded gardens with bright, long-lasting colour in summer is Impatiens.
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 Impatiens 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.
Watch out for the lily borer in clivias. 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.
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.
September is an excellent time to get in there with some pinching, deadheading, and pruning.
Most flowers benefit from deadheading – which means having their spent flowers removed.
It helps to ensure that your flower garden will be healthier and stay in bloom throughout the season. 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.
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 garden centre for advice on the best products to use.
No South African garden should be without the beautiful blazing orange of a blooming clivia.
Clivia minniata is one of our more famous plants in South Africa and it has managed to find its way into gardens around the globe. Not only do clivias produce amazing flowers during spring, but they also continuously multiply over time. What’s more, being indigenous, they are used to our extreme South African weather.
Clivias prefer to be planted under evergreen trees or shady areas. They also work great in containers, which enables one to move them around.
They dislike the hot afternoon sun which can burn their leaves and should also be sheltered from heavy frosts. A soil with adequate drainage and loads of organic matter topped off with a layer of mulch is preferable.
To get the best out of your clivias, feed them before and after flowering with a fertiliser for flowering plants such as 3:1:5.