THE MULCH STORY

(One of a series of articles about growing fruit trees in Samoa, written by Digby Gotts and published in the 'Samoa Observer' between December 2000 and April 2001)

One of the first things I noticed in Samoa was how neat and tidy it seems everyone keeps the spaces around the fales. Sweeping lawns maintained within an inch of their lives and wide expanses of swept sand make for a clean and tidy first view that wins marks from the authorities but can produce problems for growing fruit.

If you are growing a fruit tree, it must be that you like getting fruit from it. The reality is that so often people plant a fruit tree hoping for the fruit, but after a few years not much is produced, so they give up and buy it instead. Quite often, their tree is sick or dying because it has to spend all its effort defending itself from the grass and has no energy left to produce fruit. You see, grass is designed to grow in full sun and has developed a poison that it releases from its roots, which slows or stops other plants from growing and so puts more sun onto the grass. Remember all those wide prairies or grasslands or veldt or pampas (choose your continent). That’s one of the reasons why there are very few trees in those places. The grass has taken over. The trees that are there have developed immunity to the grass poison and so can grow, but there are very few fruit trees that can tolerate the poison.

Covering the soil with sand around the fruit tree and pulling out the weeds is marginally better but even here there are problems. Fruit trees usually have roots right up to the surface and those roots that develop in or near the sand are very easily disturbed and killed when the loose layer dries out or is swept.

So that sweeping lawn or bare ground up to the fruit tree stem has to go if you want fruit. Not all of it, just the bit that’s under the leaves of the tree. Commercial growers spray herbicides, but this costs money, has to be repeated every few months and, in this climate, often leads to erosion problems under the trees. The simplest way of getting rid of the grass without cost is to make this area the final resting place of your old Samoa Observer newspapers or cardboard boxes. Just open them out and lay them down on the grass in a layer around 5 – 10 paper layers thick, right out to the leaf edge. Cover the paper with grass clippings or banana leaves or just about anything that was once alive. This second cover of mulch is essential if you don’t want the paper blowing everywhere once it dries out. Deprived of light, the grass will die and decay, feeding the roots of the tree underneath.

The paper/mulch layer will last for about 6 months in this climate before grasses invade and cover it again. You can do another paper/mulch layer when that happens or plant your own ground cover into the mulch as soon as the grass underneath has died, say 2-3 months after the first layers were put down. There are several local ground covers that look like a type of small 3 leaf clover, forming dense mats where they succeed. Pull out several finger size pieces and push them into your mulch layer. They should take root and eventually cover the mulch with a green grass proof layer that will also feed your fruit tree. So keep in mind the hidden costs of looking good, and make sure that you don’t kill the tree that lays those golden fruits.