A great result: weed-free soil, seedling level with the soil surface, treeguard covered to one third of its depth, and perfectly square so that it stays open all summer long to let light and water in.
The summer of 2003-04 was notable for very poor rainfall — almost 50% below average — but twelve months later around 95% of the plants on this site were healthy and growing steadily.
Now it's the turn of the planters. Planting a tree sounds simple enough, but there is more to this task than meets the eye.
Let's start with the plant itself. This one is a Golden Wattle, one of the several different acacias native to the district, and a very important part of a healthy woodland ecology. Wattles fix nitrogen in the soil, and thus provide vital nutrients that help other species grow strong and healthy; their seed is important to many creatures, especially seed eating birds like Bronzewing Pigeons; finally, small marsupials like the Sugar Glider and the threatened Squirrel Glider depend on wattle sap for the major part of their diet.
It is important to extract the plant from the tube as gently as possible. The less we can disturb the root system, the faster the little plant will adapt to its new location — and within a month or two it will have to deal with the heat of summer, so it needs all the help it can get.
The best method is to turn it upside down and tap the edge of the pot smartly against something firm (such as your knee). With a little practice, you will find that most seedlings pop straight out of the tube with the root system intact.
Next, we stick it in the ground and fill the hole in, right?
Well, yes, but we keep that root system intact by doing it gently, and make sure that the plant is level with the soil surface — if it is below the surface level it gets waterlogged or dies of collar rot; if it is sticking up above the ground, it dries out and dies as soon as the warm weather arrives.
(Sometimes, depending on the site conditions and the particular species being planted, we make exceptions to the general rule: someone will let you know if we need to plant deeper or shallower than normal.)
Finally, we fit the treeguard. The guard helps conserve moisture and protects the seedling against rabbits, hares, and kangaroos — grassland species like hares love to nibble young trees right down to the ground, often ignoring tasty-looking grass nearby. The guard needs to be anchored firmly: kangaroos and cockatoos can easily pull out treeguards if they are not weighted down; the roos like to get at the tasty young plant, the cockies seem to do it just because it amuses them!
This is why we need that generous pile of clean, weed-free soil the digging team left: we use it to cover the treeguard all around to about one-third of its depth.
Over the next few years, the treeguard not only discourages hungry herbivores, it also protects the seedling from the elements and functions like a tiny humidicrib, collecting dew and retaining moisture in the soil for baking hot summer days. Being made of cardboard, it will gradually break down and by the time the young tree is three or four years old and growing strongly, the guard has rotted away to nothing.
Why not use plastic guards and stakes? Wouldn't it be quicker and easier that way? Yes it would, but it creates litter that needs to be cleaned up in future years, and there is always a small gap between the bottom of a staked treeguard and the soil surface which allows the hot winds of summer through, resulting in less soil moisture and a higher failure rate.
Overall, our planting technique is slow, sometimes tedious, and requires a great deal of physical labour. That effort, however, is amply repaid by extraordinarily high success rates. We aim for 100% success each time we plant, and often come remarkably close to it. After all the planning and seed collection and propagation in the nursery, and the ripping and spraying and fencing, and then the digging, planting and guarding, the young trees and shrubs are on their own. Even in bad years, nearly all of them survive and go on to lay the foundations for a healthy, rejuvenated ecosystem.