The Zimbabwean Gardener Issue 10 Spring 2014 | Page 21

Tree ferns Dicksonia antarctica Also called ‘The soft tree fern’, needs a shady area in which to thrive. They have a beautiful green whorl of fronds, but the plants are short and broad. Not fast growing but make a stunning focal feature in a shady spot. This is one of the most popular tree ferns on earth and grow in Tasmania by the tens of millions. Unfortunately, they only produce spore on a plant at twentythree years or older, which is why they are so expensive in Zimbabwe! Cyathea manniana So the question remains what tree fern should we grow in our gardens? The answer to this is that we must plant exotic varieties that we commonly refer to as the ‘Australian tree fern’. To some of you, this will be distasteful as indigenous plants are the only way to go! There are approximately 1,000 different species of tree ferns known as Dicksoniaceace and Cyatheaceae. The Dicksoniaceae, which only have about 25 species, are more primitive or prehistoric than Cyatheaceae, their fronds are also coarser and look less waxy and are covered in fine hairs rather than scales. Cyathea is derived from the Greek word ‘Kyatheion’, which means ‘little cup’, referring to the structure that holds the spores on the underside of the fronds. It is from these spores that tree ferns can reproduce, as these are the so-called ‘seeds’ of these giant ferns. The ‘Aussie tree fern’ Some varieties of what we like to refer to as the ‘Aussie tree ferns’ grow extremely fast, but only the Cyathea australis and C. cooperi and Dicksonia antarctica are indigenous to Australia, growing in the tropical, subtropical and temperate rainforests. Here are some common exotic ferns available in Zimbabwe: Hivu Nursery Hivu Nursery on the Main Vumba Road sells tree ferns, ferns and other shrubs, ground covers and hanging baskets. You can also rent holiday cottages and go horse riding. Open seven days a week Dicksonia antarctica Dicksonia squarrosa Known as the ‘Rough tree fern’, is a common tree fern and endemic to New Zealand. Their growth and appearance is very different to D. antarctica, as they grow up to 6m, forming an umbrella above a thin black hairy trunk. They are relatively hardy to sun and wind, and grow happily in partial shade. Although they are not fast growing, within several years you will have a magnificent plant. Cyathea brownii How to grow Aussie tree ferns Aussie tree ferns need to be planted in an area with rich, well-drained soil, and protection from wind. They are not very water wise plants, as they must be well watered, especially during dry periods and high humidity. They can be watered from the top where the delicate uncurling fronds, called ‘crozier’, rise. Where to plant them Growing a tree fern is a wonderful way to add a sense of the jungle and lushness to any garden. Although they are in fact trees, most gardeners plant them as a medium sized plant in shady areas removing them when they get too tall. Try them as a feature plant in a shady courtyard or under a bigger tree where you can allow them to grow to full height and you will marvel at the sheer beauty they bring. Dicksonia squarrosa Cyathea brownii Cyathea brownii is another common ‘Aussie tree fern’, also known as the ‘Norfolk tree fern’, from Norfolk Island