Do you speak tree?
Written by Georgina Lockwood on behalf of Life Green Group.
When installing a tree on a landscaping site Life Landscapes has to take into consideration many things. Planting a tree is a 20 year investment and you need to make sure you do your investigation root and branch!
Depending on the motivation for planting the tree, here is what a responsible landscaper does before purchasing or ordering a tree. Life Landscapes has also included examples of trees under each category.
The definition of an endemic tree is a plant that is native or restricted to a certain biome or region. The Kei white bauhinia (Bauhinia bowkerii) is endemic to a small area by the Kei River in the Eastern Cape. Endemic plants often look best in times of drought and serve important ecological services in their native area.
Is a tree that occurs naturally in specific place or country. The Kei white bauhinia (Bauhinia bowkerii) is indigenous to South Africa but is not endemic everywhere in South Africa. The wild olive (Olea europaea subsp. Africana) and the Sweet thorn (Vachellia karroo) are indigenous to South Africa occurring across different biomes and rainfall regions.
Exotic trees were brought over in the colonial period; these trees neither harm nor benefit the environment. Maple trees and frangipani trees are exotic trees in Africa.
Invasive trees are illegal and harmful to local biodiversity. They impair natural ecosystems, take up too much water and spread uncontrollable. Mediterranean pines, Jacarandas and African tulip tree are all illegal species in South Africa.
Small garden trees:
Are trees that take up minimal space and only get so big, a lot of shrub species make for excellent small garden trees if pruned correctly they can have a single stem.
Are trees that can be used to line avenues and roadsides. These trees generally do not spit sap, don’t have invasive root-systems and provide excellent shade with flat crowns.
Are often large trees that are also referred to as lawn trees. They provide deep or dappled shade. These types of trees are particularly good for school play grounds, livestock and wildlife that use the tree for shade and shelter.
Interesting fact: the best time to plant a tree in South Africa is March/April or August/September.
There are not many indigenous screen tree species in South Africa but these trees have large bushy crowns. Some good screen trees in South Africa are the forest elder (Nuxia floribunda) and wild olive.
Generally serve an ecological purpose for wildlife as they are an important food source for game, livestock, insects and birdlife.
Are trees with a statuesque shape that get large celebrated flowers that are appreciated by humans, a lot of popular exotics like the magnolias and jacarandas are considered to be ornament trees.
When planting the tree always dig a square hole and not a round hole.
Everyone knows a tree is comprised of roots, a trunk, branches, leaves, pods or fruits, flowers and for some thorns. But these features can have a significant impact on a garden:
Trees have two types of root systems. Tap roots or Fibrous root systems. Fig (ficus) trees have fibrous root systems and are known to uplift paving and damage infrastructure. This is why tap root trees, known as dicots, are a more popular garden specimen.
Most trees are single stem trees, the smaller shrubs tend to have multi-stems. Landscapers often look at the trunk and the bark for variegation.
Trees have adapted to have different crowns so depending what your aim is here is what you should consider:
- Flat crowns
- Columnar crown
- Fountain crowns
- Weeping crown
- Pyramid crown
- Layered crown
- Round crown
Deciduous versus evergreen? Evergreen trees require less sweeping while deciduous trees give you fantastic autumn colours and free mulch for the soil. The pompom tree (Dais cotinifolia) and indigenous Combretum species are great examples of deciduous trees.
Flowers are often what make a tree popular. Landscapers will sometimes consider the garden colour palette before planting a tree. The nectar-filled flowers attract sunbirds, while pollen packed blossoms bring bees to the garden.
- Pink palette garden: Cape chestnut (Calodendrum capense), and river indigo (Indigofera jucunda)
- Red coloured garden: Erythrina species, Natal bottlebrush (Greyia sutherlandii), tree fuschia (Halleria lucida)
- White palette (moon garden): Forest elder, Transvaal gardenia (Gardenia thunbergia) , common rothmania (Rothmannia capensis)
- Purple palette landscape: Tree Wisteria (Bolusanthus speciosus ) and cork bush (Mundulea suberosa)
- Yellow theme garden: Yellow tree bauhinia (Bauhinia tomentosa), African wattle (Peltophorum africanum), African teak (Pterocarpus angolensis) and wild laburnum (Calpurnea aurea)
Fruits and seeds:
Not all trees are fruit bearing some only get seeds. Fruit trees are fantastic for attracting fruit-eating birds to the garden. Traditional fruit trees, like lemon trees and fig trees, are also a useful in the garden.
Most indigenous trees are able to grow in parts of the country that they are not endemic to; however, some trees are only suited to growing in certain conditions. Cape Town has a winter rainfall so not all trees survive in the climate. Southern Gauteng is prone to frost killing most tropical trees from the East Coast. The Northern Cape and Free State are not high rainfall areas so only desert adapted trees grow. Large trees struggle to grow directly on the beach, certain shrubs with adapted leaves can handle the salt from the ocean.
- Frost affected area: Cork bush (Mundulea sericea), Jacket-plum (Pappea capensis) and lavender tree (Heteropyxis natalensis)
- Water-wise/ desert garden: Spekboom (Portulacaria afra), Chinese lantern (Nymania capensis), Cape ebony (Euclea pseudebenus), Camel thorn (Vachellia erioloba)
- Winter rainfall: African holly (Ilex mitis), white pear (Apodytes dimidiata), tree fuchia (Halleria lucida), puzzle bush (Ehretia rigida) and Karoo boer-bean (Schotia afra)
- Salt tolerant: Yellow tree bauhinia (Bauhinia tomentosa). Num num berry (Carissa macrocarpa), tree hibiscus (Hibiscus tiliaceus), Umzimbeet (Millettia grandis) and tassel berry (Antidesma vensum)
Questions to ask when planting a tree:
1) Size. How big will the tree get and is it too big for my garden?
2) Roots. What type of root system does it have and will it damage infrastructure where I want to plant it?
3) Water. With South Africa’s current water restrictions, is it water-wise and is it indigenous?
4) Region. Where is the garden? Can this tree survive in my specific garden conditions
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