The building of a food forest as part of a natural carbon sequestration machine involves preparing the soil, and planting up thickly with hardier food plants and support plants, and adding until all the tiers of the food forest are complete. Hardier plants should act as pioneers and the other productive plants can be planted in later. There is no greater authority on the subject than Geoff Lawton, but other ideas are welcome and you can send me a comment on the bottom of the page.
Therefore, let me start by listing my trees grown from seed and cuttings. In the tree
layer there will also be the native leguminous trees as support species. I will cover them
in another article.
These tree planting suggestions cost nothing except water. They can grow from seed, its so easy. Just collect seed from parking lots, street trees and parks. I will recap with a list at the bottom.
Umgwenya (native to the eastern regions of South Africa)
The tallest tree, topping canopies in
the east of South Africa is the wild plum. Wild plum or Umgwenya
(Harpephyllum caffrum) take many months to germinate, but with enough
seeds, and the trees shed a lot you will get results. The thin
skinned berries had the highest antioxidant levels of a suite of
about ten known high anti-oxidant berries like blue-berrries, so they
are among the anti-oxidant richest cultivated berries in the world.
The saplings can grow in small containers and get really root bound
without dying and need little water. The adult trees grow slowly in our
neighbourhood in deep sand, dry for much of the year, but their roots
appear to be invasive, lifting walls and tarmac, but not as badly as a
ficus. I have a page on growing them here.
Indoni (native to eastern and northern regions of South Africa)
next. It can grow very large, but in parking lots it remains small
for decades. If you remove the fruit, the little green seed grows
easily. Germination is also slow. The saplings need a lot more water,
even after planting out. Find out more about growing them here.
Cork oak (native to the Mediterranean)
Cork oak is another very big tree in
some circumstances, when very old, and a stunted short tree in
others. Cork oak (Qercus suber) is very easy, but also takes a while
to germinate. I have close to 100% germination. The roots grow
rapidly and can emerge from the bottom of the pot before you even see
the first leaves. Apparently being root bound stunts the trees in the
long term. In my tiny garden stunting is actually an advantage. I
planted acorns in a tray so thickly they were edge to edge. I
transplanted them into individual bags once they were 20cm high. The
death rate was really low. They are definitely hardy, but dislike
getting dried out, or suffering hot dry winds as saplings in the bag.
The bark of cork oaks is used to make cork and can be stripped
without killing the tree. The bark also makes them quite drought
resistant as cork is only slightly water permeable. The acorns are
edible but the process of leaching out the bitterness is tricky. The
saplings need more water than Harpephyllum. See how to do it here.
Carob (native to the Mediterranean and middle east)
Carob trees get quite large, with a large umbrella shaped spread. Carob also has a large hard seed and takes a long time to germinate, but germinates well in terms of numbers. They grow very slowly and there seemed to be a problem with them not liking wind and direct sun as seedlings. Perhaps a slatted shade house would be ideal Here is my page on growing carob.
I move on to trees I've grown from cuttings
Olive (native to Europe, middle East and Africa)
Olives are very useful and beautiful
trees. I took hundreds of cuttings to get a couple of viable rooted
branches. In my experience a nice thick stick with an elbow roots
better. Cigar thickness as opposed to the recommended pencil
thickness was better. With consistent watering the leaves stayed
green and didn't drop for a whole year, but I found no roots had
developed on most of them. With bottom heat, hormones and spray
irrigation, rooting is said to be up to 90%, but my primitive methods
obviously fell far short of that. I didn't try growing from seed,
because I wanted to clone from a very productive tree that I have. I've pages on olive propagation and harvest.
Elderberry (native to Europe and north America, depending on species)
Elderberry works well from cuttings, almost 100%. Definitely cover the cuttings with a tranparent plastic bag to keep them humid, and in a spot thats not too hot. They are soon large enough to plant out, but they need a lot of water.They are pretty small trees, so I will include them again in the understorey section later.
Mulberry (native to Asia and Americas)
The mulberry is similarly easy to propagate. It is invasive, as is the Elderberry. Don't plant in areas where they can turn into a problem, like along river courses. The saplings need less water than the elderberry and waterberry but more than a carob for instance, and definitely more than Umgwenya or wild plum.
Plum (native to Europe)
I've had some success with plum
truncheons (cuttings that are several meters in length), but I
haven't looked at the roots yet. They may just be leafing well
because of the stored energy in the wood. They do not like the wind.
Most of the cuttings need to be protected from the wind while
rooting.They probably are better suited to the later stages of the food forest's development. That is one could plant them into the half established forest after a couple of years, when there is sufficient height to offer wind shelter.
So that is my list of some basic trees that are tough enough to go into the first planting of a Mediterranean food forest, with support species, in an area such as Cape Town which is on the drier, hotter side of "Mediterranean". I will talk about native support species, and the under storey, shrubs, herbs and ground covers in later articles. I already have a large collection of perennial food plants, a mix of all sizes of plants, as well as many articles on composting, mulching and conserving water. The links are on the carbon sequestration page you can click on below.
Success guaranteed in Cape Town, South Africa with