Gauteng Smallholder July 2017 | Page 37

INVASIVE ALIENS Replace aliens with indigenous lookalikes Y ou might not wish to cut down an estab- lished tree on your property just because it is an alien unless ordered to do so by an authority because such an action may leave an unsightly gap in your garden. However, there is good news: in many cases you can go ahead and remove alien trees, replacing them with indigenous alternatives which perform in much the same way in terms of shade, height From page 33 way that they each grip the wire to be tensioned, and the harder you pull the handles together the harder they grip the wires, so there is no danger of them loosening, even on smooth wires. Because of the length of the handles,(which can be made as long as you like by slipping a piece of pipe over each and spread, and which are less damaging to the environ- ment. The Gauteng Smallholde r has written extensively over the years about the challenges we face in dealing with invasive alien plants (IAPs). And, of course, winter is a good time to cut down exotic trees or remove dead ones and to replace them with a suitable indigenous tree. Our focus would be on eliminating invasive aliens, which are a threat to our natural biodiversity. What makes an alien plant become an invader? K Absence of natural enemies. K Similar conditions to native country. K Vegetative reproduction. K Prolific seed production, long-lived seeds. K Effective seed dispersal mechanisms, such as water, wind and birds. However, just because a tree is indigenous doesn't mean that it will grow well on a Gauteng plot. Trees from the Western Cape with its wet winters or from some areas in Kwa Zulu Natal will find our frosty winters too hard to handle. A common alien tree that should be replaced is Acacia mearnsii or Black Wattle. This tree competes with and replaces indigenous grassland and riverine species. Your handle end) you are able to achieve a good strong tension with the force building up on much the same fulcrum principle that a nut-cracker works on. When you have the wires as taut as a guitar string, a chain is hooked between the handles to hold them firmly together. A piece of flexible binder wire is then twisted around the wire to be tensioned outside each of the handles and, using a screwdriver, the handle of your fencing pliers or a fencing tool, you twist the wire around and around the wire to be tightened, each twist drawing in the slack and making the fence taut. This is achievable, without becoming entangled with the tool, because the fulcrum of the two arms is kept well away from the work area by the length of the arms, and a short piece of steel that joins them. Once you have achieved the desired tautness, the securing chain is detached from one arm and the tool removed to reveal a perfectly-tensioned wire, as taut as it was when you were working on it. The fence tool may be ordered from Backsaver and can be delivered by mail. For more information: Michris Janse van Rensburg, tel 073 454 -111 35 www.sasmallholder.co.za Continued on page 36 USEFUL STUFF