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Fynbos gardeners: Why you should get your hands dirty this autumn

MAY 19, 2023  | PRESENTED by ANNERIE SENEKAL. Photos by ANNERIE SENEKAL

Above: Ferraria crispa. Photo by Annerie Senekal

Autumn is the ideal time for fynbos gardeners to get busy.

From your beautiful spring-flowering geophytes, such as the gorgeous Gladioli, to spring-flowering annuals, including some dazzling daisies, there are many options to plant in your garden or your outdoors space now, to create a kaleidoscope of colour later in the year.  

In fact, says assistant curator of Stellenbosch University Botanical Garden, Annerie Senekal, with some careful planning, autumn is the best time to sow most Cape seeds. Because of the unique climate in the Cape Floristic Region (it is the only South African region with a Mediterranean climate), plants often go dormant during the summer, with most plants starting to grow actively again in autumn. She offered some valuable insight to Cape gardeners.

Above: Pauridia capensis. Photo by Annerie Senekal

Get going with geophytes

The Cape region is extremely rich in geophytes. Most of them make excellent garden plants and since they don’t require a lot of space can be perfect for a sunny stoep or balcony. Autumn is the perfect time to plant spring-flowering geophytes such as Gladioli, Moraeas, Babianas and Freesias. A general rule of thumb is to plant the bulb 2-3 cm under the soil. The exception here is Amaryllidaceae – these bulbs have necks, which should always be exposed above the soil.

Remember that most Cape geophytes like well-drained soil that need not be rich in organic material. Plant them in full sun, give them a good drench and – once they start pushing out leaves – water regularly throughout autumn, winter and spring. Once the plants start showing signs of die back, stop watering to give them a rest period over the summer.

Above: Cape geophytes bulbs. Photos by Annerie Senekal

Annerie says, “The nice thing about Cape geophytes is that different groups flower at different times of the year, so if you plan your garden nicely, you can pretty much always have a geophyte flowering.”

For example, Oxalis species are very forgiving and easy to grow, and come in a variety of shapes, sizes and colours. They can provide colour to your garden throughout autumn and winter, but they are best planted by February at the latest as they already start growing in early autumn.

Top left: Gladiolus debilis. Top Right: Moraea gawleri. Bottom: Babiana nervosa. Photos by Annerie Senekal

Using smoke treatment for seeds

Because many fynbos seeds need fire for germination, consider using smoke treatment when preparing your autumn seeds. Smoke treatment is available at local indigenous nurseries, or you can try a DIY method by burning dry leaves, grass and newspaper and blowing smoke over your seeds for at least 10 minutes. Annerie says, “In my experience, most Cape seeds respond positively to smoke treatment, even if they don’t exclusively need it to germinate. So if you’ve been struggling to germinate certain seeds, you can give smoke treatment a go and maybe it will improve your success rate.”

Recalcitrant seeds are fleshy seeds that cannot be dried and stored. They have no dormancy period and germinate soon after being sown. Cape plants with recalcitrant seeds, like many Amaryllids or the majority of Cape Oxalis, typically flower at the start of or during the rainy season (i.e. autumn or winter in the Cape) since moisture for germination is guaranteed.

To sow recalcitrant seeds, Annerie suggests making a small depression in your soil and placing the seeds on top. There is no need to cover them, and you can immediately water them. Keep the seeds moist and keep watering regularly once they start growing.

Above: Cape Oxalis. Photo by Annerie Senekal

“Sowing seeds is a long-term investment and, unless you’re sowing annuals, most of these plants won’t flower in the first season after sowing,” Annerie explains. “But the nice thing about sowing seeds is that it’s an effective way to get a lot of one thing in your garden. So if you’re patient, it will pay off.”

Make sure you sow your spring-flowering annuals in autumn – consider Nemesias, Heliophilas, or many species in the daisy family. Choose a windless day to sow them directly into your garden bed and cover with a fine layer of soil.

Annerie says, “We have quite a lot of blue annuals available in the Cape, and the gardeners among us will know that blue is a difficult colour to find for your garden, so we are quite lucky in this regard.”

Above: Ixia dubia. Photo by Annerie Senekal

Propagating succulents and shrubs

Autumn is also a good time to make cuttings of succulents just before they enter their active growing season. The easiest and quickest way to propagate succulents is to cut off a 10 cm piece from the stem, let it dry out for a day or two to prevent rot, and place it directly in well-drained soil. Be careful of overwatering early on – once it has produced roots and shoots, you can start watering more regularly, especially during the growing season.

Above: Propagation bed. Photo by Annerie Senekal

Cape shrubs can be transplanted, moved and divided in autumn, but don’t prune them this time of year. Many species have already started forming flowers for springtime – which is also a good season to make cuttings – so you wouldn’t want to chop them off.

Annerie also encourages gardeners to reach out to their local BotSoc branch or botanical garden to help find specific local species and to avoid taking cuttings from the veld.

Above: Romulea hirsuta. Photo by Annerie Senekal