Over the past few weeks, M and I have been compiling a list of trees to create the main structure of the garden. Our priority is for fruit trees, but we also have to consider windbreaks to protect the garden from strong winter and spring winds. The windbreak candidates are:
- Deodar cedar (Cedrus deodara)
- Silverberry (Elaeagnus)
- Feijoa (Acca sellowiana, also produces fruits known as pineapple guava)
- Sea buckthorn (Hippophae rhamnoides)
- Juniper (several species)
- Oak (Quercus ilex, holm oak, an endemic)
- Pine (Pinus pinea, produces pine nuts)
- Pitango (Eugenia uniflora, also produces berries known as Surinam cherry)
For fruits and nuts, we are considering:
- Black Mulberry
- Honeyberry (Lonicera caerulea)
- Jaboticaba (Eugenia jaboticaba)
- Pawpaw (Asimina triloba, a winter-hardy relative of the tropical annona)
- Strawberry guava (Ugni molinae)
- Yuzu (Citrus junos)
Some tropical fruits for trialling:
Ornamentals for autumn colour:
- Amelanchier (also known as saskatoonberry, juneberry) – red, orange, and yellow leaves
- Gingko – yellow leaves
- Liquidambar – red, orange, yellow leaves
- Szechuan or Japanese pepper (Zanthoxylum)
In all 40 species, though the total quantity of trees will most likely be closer to 50, as some will need cross-pollinating partners.
How best to position these in the plot? Regimented rows of trees do not appeal to me. This is after all a home orchard. Permaculture offered an initial approach to design. The tallest tree, for example, pecan, is chosen to serve as the uppermost canopy. Then according to their mature heights, trees for the subcanopy or lower understorey and subsequent lower layers are given space beneath. Vines can be made to climb up trees, provided they do their host no harm. At ground level come the nitrogen-fixers –- leguminous plants such as clover or medicago that can also serve as ground-cover to suppress weeds, or these could even be low-growing berries, such as strawberries, or vegetables, such as beans and peas. I thought peanut would make a good ground cover. They have an advantage over clover and medicago in that they not only fix nitrogen but also produce edible fruit.
What about the existing olive trees, which are in terraces? Perhaps they could be treated as part of an agroforestry trial. Although they would benefit from a leguminous ground cover, they might also do well planted with a nitrogen-fixing hedge, planted alley-fashion along the dry-stone terraces. Not all nitrogen-fixers are members of the legume family. Elaeagnus and Hippophae, which produce fruits that can be used for juice, are known to be excellent nitrogen-fixers. And both would be happy in the well-draining clay soil here, as well as the cold winters and hot summers. Their narrow blue-green leaves would go well with the olives’ silvery green. And their bright orange (Hippophae) and red (Elaeagnus) berries would make good accents throughout autumn and winter, and good bird and insect food as well. (Hippophae berries or sanddorn in German, have become a popular functional food due to their high flavonoid content, finding their way into cold remedies, therapeutic teas, soap, cosmetics, etc.).
Encouraging wildlife is another consideration. The yew, to my surprise, is endemic to Spain, and from my experience in Bonn, its fruits are highly favoured by birds and red squirrels. Although bamboo is not native here, many of our neighbours have established clumps of it. There is an interesting dimension to the native oak (Quercus ilex) and hazel – one can buy them already inoculated with truffle fungus – an additional potential harvest.
This list obviously will have to be refined further – some added, some deleted. I haven’t even checked for the possibility of allelopathic effects among these. I shall be checking out reliable sources for recommended cultivars of these trees. I prefer to look initially at nearby nurseries — around the Alicante and Valencia areas, but would also consider any further afield, if they have good stock. Your comments and advice on these choices are heartily welcome.