Piet Stoker (PhD)
Evergreen, fast growing indigenous trees
Updated: Jun 3, 2020
We often get inquiries for evergreen, fast growing indigenous trees. In this article we share our ideas and insights into the matter.
We start with a few terms and concepts.
A deciduous tree sheds 100% of its leaves, usually in autumn. It is without leaves for 1-3 months before budding again in spring.
A semi-deciduous tree sheds the previous season's leaves just before, or for some species, while budding again.
An evergreen tree sheds it's older leaves throughout the year. Leaf shedding characteristics are species dependent, but the tree is never without leaves.
Albeit that some species are more messy than others, it follows that that there is no such thing as a "non-messy tree". Leaf shedding and budding is part of a tree's growth cycle and is indicative of good tree health.
A tree's growth rate is indeed species dependent. However, apart from water, many other factors also have an influence:
Annual temperature cycle. Even though a cold winter spell may not kill the tree, it can harm the cell structure in the tree's live bark, thus inhibiting the next seasonal growth.
Soil quality is a science in own right. It includes characteristics such as soil drainage, soil acidity, availability of macro-nutrients (nitrogen, phosphate, potassium, and more) and micro-nutrients ( Iron, manganese, copper zinc and others)
Root space. A tree's root mass and leaf mass are always in balance. Restricted root space will cause slower growth and a smaller mature tree.
Age. Some tree species grow slowly when young and faster later. Others exhibit the exact opposite growth pattern.
Assuming that the above factors are all in order, we will classify growth rate as fast if the tree is expected to grow about 80cm/year; medium if 40cm/year and slow if 10cm/year. We also indicate the expected mature size of the tree -to be achieved in (say) 30 years- as very large large if the canopy exceeds 30m diameter, large if 15m, medium if 7m and small if 3m. So here goes!
If your minimum temperature stays above -6 degrees Celsius
It is clear from the above table that there is no medium size indigenous tree which is "evergreen and fast growing", and also able to withstand severe frost. If you desire a medium size tree you will have to be patient.
My recommendation for a small garden is Blue guarri. Follow the link to find more information https://www.indigenoustrees.online/euclea-crispa-blue-guarri
My recommendation for a large garden is to plant 3 False olives together in a triangle.
If your minimum temperature stays above -2 degrees Celsius
Clearly you have a much wider choice when experiencing only light frost. Obviously trees listed under -6C will thrive in a -2C climate, so add them to your options list. Observe that fast growing trees tend to grow big, which reduces the options for a small garden.
My recommendation for a small garden is either Horsewood or Mountain hard pear. https://www.indigenoustrees.online/clausena-anisata-horsewood
My recommendation for a large garden is either White pear or Waterberry.
If your minimum temperature stays above 0 degrees Celsius
As before you may add -2C and -6C trees to your options list, resulting in an almost overwhelming number of choices. A frost free climate opens the door for planting trees that grow to a very large size, for example the Njala tree. Take advantage of the privileged position you are in!
My recommendation for a small garden is Tassel berry
My recommendation for a large garden is Jackal berry