Gardening: wait for the rain flower and enjoy the purple rain

Published Oct 21, 2017

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The recent storm showed how weather can change a landscape in just a few hours. 

I was coming back from Umkomaas in the pouring rain on that fateful Tuesday, trying to find the safest way home on roads that were flooded. I managed to get back on to the N2 near the old airport to be caught in a traffic jam with nowhere to go. 

When I saw the water level rising I started to realise that I was in trouble, especially when a small car came floating past me. To cut a long story short, my new bakkie was flooded and has been written off because of extensive damage. Luckily my staff and I managed to climb out of the window to safety. Waking up the next day to a beautiful sunny day, it felt like nothing had happened the day before. I just hope some of the rains fell in the dam catchment areas.

It is fun watching spring unfold in front of your eyes with trees pushing new leaves out within a few weeks. Most trees would have leafed out, erasing any signs of winter. October is also jacaranda season, with the Argentinian tree Jacaranda mimosifolia in full bloom all over South Africa. I know it is an exotic, but it is still very pretty. 

If you want to know if it may rain, wait for the plant many people call the rain flower to flower and, most likely, it will rain within a few days. The Dietes grandiflora, better known as the large wild iris, is commonly grown in gardens and used extensively in the landscape industry throughout South Africa. It grows into large clumps from an underground rhizome, is evergreen and grows to about 1.5m in height. It makes a wonderful filler plant that can grow in full sun and shade. It has long, rigid, sword-shaped leaves, held in a fan shape with dark green leaves. 

It is the flowers that make it so special. The flowers are large and white with yellow nectar guides and a violet central segment. Sadly the individual flowers do not last more than a few days so it’s no good for flower arranging or a vase. The big bonus is that they produce so many flowers at one time that it becomes a very striking plant in the landscape. Another common name is the “Fairy Iris” as the white petals often look like fairy wings and also the flowers can disappear overnight. Once pollinated, it produces a large green fruit that turns brown before splitting open to release shiny, dark brown seeds.

Dietes grandiflora grows naturally along the eastern areas of the southern Cape, Eastern Cape and southern KwaZulu-Natal. The name Dietes means “having two relatives” and refers to the relationship between this genus and Moraea and Iris. Grandiflora means “large flower”. Dietes has a rhizome and Moraea a corm so that clearly distinguishes them from each other. Dietes was once called Moraea but they were separated because of this difference. From a landscaping point of view, Dietes is popular because of its reliability and hardiness, and it is often found in parking areas at shopping centres, schools, etc. It can be used effectively in mass plantings, but is also effective in mixed plantings or as an accent plant alongside a pond or some steps.

It is very easy to grow and can survive under most conditions. The plants are frost and drought-hardy. For best results and the most flowers, plant Dietes grandiflora in full sun or light shade in well-composted, well-drained soil and water well in summer.

The large wild iris is easy to propagate from seed sown in spring or by dividing large clumps which spread by means of rhizomes. They multiply rapidly and are soon ready to be split again. 

If you are looking for a plant that grows quickly, requires very little attention and is rewarding, then this is your plant. If you have a large garden and do not have much money for plants, then speak to friends who have large clumps of Dietes in their gardens. Dig out a few large clumps, split the plants, then plant each individual split about 30cm apart. Water well in the first few weeks. When you see the new growth appearing, reduce the watering. Within a year you will have a full display of Dietes. Happy gardening!

What to do this month

We are between seasons for many flowering plants, but still we have a number of shrubs and groundcovers in flower: Mackaya bella (forest bells); Tecoma capensis (Cape honeysuckle); Turraea obtusifolia (small honeysuckle-tree); Becium obovatum (cat’s whiskers); Agapanthus praecox (Agapanthus); Tulbaghia violaceae (wild garlic); Chlorophytum bowker (hen and chicken); Clivia miniata (Clivia); Crinum macowanii (river lily).

My Crinums are being eaten by the Amaryllis caterpillar. I just leave nature to do its thing, because once the leaves have been decimated they will produce a flush of new leaves. Mackaya bella are in flower. Once they have finished flowering it is best to cut these shrubs back, because they can become very overgrown and woody. The new growth that will appear soon after pruning will allow the shrub to grow and produce new healthy growth for the next season and to grow into a neat well maintained shrub. It will flower again next season.

Last month I gave you lots of info on lawn care. Follow my instructions for a good healthy lawn. No matter how poor a garden looks a well maintained lawn will change your perception of that garden.

Split and replant groundcovers such as Dietes, Tulbaghia, Crassula, Cotyledons and Chlorophytum.

Do not split  Agapanthus, because they flower in summer and will be in full bloom soon.

Enjoy the beauty of Clivias. They are a very rewarding groundcover that flowers best in deep shade. Once they have finished flowering, you can divide these plants. You can put them in the ground, but the moles love them. If you really want to grow fantastic Clivias, put them in big pots that you can move around the house or garden. Keep them well watered and fed.

It’s an ideal time to repot indoor and outdoor pots. Remove the plant from the pot and remove most of the old soil from around the roots. Wash off excess soil with water and then replant the plants in the existing pot, using fresh potting medium. Reduce the size of the plant by pruning some of the leaves and side branches to prevent the plant from wilting. Sprinkle some blue chips on the top of the soil. This is a high nitrogen fertiliser that will boost the growth of the plants

It’s important to feed your lawns and flower beds during the summer rainy season. The days are longer and warmer, thus the roots take up lots of water and nutrients. 

For lawns use a high nitrogen fertiliser such as LAN or 5.1.5. Apply a handful per m². 

Water well after application. For flower beds use a more general fertiliser such 2.3.2 or 3.2.1. Apply as you do for the lawns and water well after application.

This article is sponsored by Chris Dalzell Landscapes, specialising in landscaping, consultation and botanical expeditions. If you have any questions, please e-mail me at [email protected]

The Independent on Saturday

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