By John Warrington
I briefly talked about using chemicals towards the end of last week’s column. Let me continue for a while this week. If you have to use chemicals, don’t use them as a routine to control a pest or a disease which you have, or which you may get in the future. The very best way is by cutting out infected branches or picking off infected leaves. Use a chemical only when you really have no other option, otherwise you may end up with a very serious problem. The reason for this is that pests and diseases become resistant to every chemical you use when you don’t really need to use them, and you end up employing ever stronger chemicals which are ever more dangerous.
Pests and diseases behave in much the same way as the weakest animal or plant. So cut out branches and shoots which continue to attract certain pests and diseases, or just do not grow them at all. However, if there is a plant that is the only one of its kind in a collection, most of us will try to save it. I certainly would. Just try and make it stronger. It’s really only the weaker plants that become infected. So improve drainage by regular mulching, or mulch regularly if you want to retain water. Once again, remove diseased leaves, shoots or branches as soon as they appear. Make sure that the plant is getting sufficient light or is not in too much shade, or exposed to too much breeze. Remove dead or dying flowers. The most important thing is to keep a regular look-out for any of these things as you walk around the garden. If there isn’t a problem, then don’t try and fix it! Remember that mealy bugs and scale insects are particularly damaging, and often the best way of killing them is with your fingers. This also applies to attacks of greenfly or blackfly – but do it gently.
Some years ago I finally got rid of the last of my guava trees – a poor specimen that had inherited none of the good characteristics of its parents. Although we humans don’t have a lot of choice about the characteristics we receive from our parents we do have plenty of opportunity to influence the plants we have. For generations gardeners have tried to improve plants by breeding and crossing. We have tried to improve flowers, disease resistance and yields of crops by crossing and back-crossing species for years, sometimes with remarkable success. Now science has developed quicker ways of improving plants; of doing something that the early gardeners and farmers took years to do. What we did fifty or more ago was just called plant breeding. Now the same process is called genetic engineering. It’s more or less the same thing, but because the process has become far quicker than it used to be, the less informed have become hysterical about it. Well in time I expect it will all settle down.
The year before last I had some security lights placed around the house. They work on the photocell principle, coming on at about 5.30pm. And switching off at about the same time in the morning. This means that in the immediate surrounds of the house we have light for 24 hours. I have wondered whether this has been the cause of the cessation of flowering of my spectacular white-flowered euphorbia called the Pride of Barbados. Could be, as all the euphorbia group responds to day length, including the poinsettia that is so loved at Christmas. Don’t worry, take care, and may your God go with you.
