I'm working on my aunt's garden in the South-East of France (the Var region) and have a question about Olive trees. I couldn't find much info on olives on the forum and the info I'm usually getting from Google doesn't quite suit my needs, I believe others truths are out there.
I want to know :
- what kind of guild you would set up for an established vase pruned olive tree orchard ? (I saw in https://www.babylonstoren.com/, in South Africa, that they used rosemarry as a cover crop and citrus as guild trees, what else ?)
- would you mulch the ground of the olives or is it bad for too much moisture (it is really hot and dry here, except for a couple of very very heavy rain falls a year) would agressive mushroom develop (that's what they say here) ?
- finally, what would you do with all (and its a lot!) of the pruned branches and leaves every other year ? people here burn them but I can't accept to burn all of this carbon matter out in the open air, especially as the soil really needs carbon and attention here... I'm growing mushroom on the eventual chopped wood we are making (oak mostly) but what about olive wood/branches... ?
Many olive farms here in Turkey are growing Narcissus/ Daffodils in their olive gardens. It is a new trend. The main purpose is to create a secondary income by selling flowers (in feb - march when other incomes are low). They plant highly fragrant types of daffodils. Here is a link to one of them, who is also selling bulbs, link - in turkish (you can use google translate for English). I plant comfrey, rosemary, lavender to make it look more pleasing and thyme and type of Mesembryanthemum (we call it persian carpet flower google pictures- to cover the soil around the tree. Does it help olive trees, I don't know. It looks nice and tidy. I am bit north for growing olive trees.
In Turkey we incorporate goats to olive tree orchards. I suspect a substantial part of their diet is olive leaves and branches. They keep the orchard clean olive trees pruned. Gökçeada (an island close by Dardanelles strait) is known for its wild goats and olive trees. Here is a link to one study what impact has feeding olive leaves and branches to goats fao-page. Here are the conclusion remarks of the study (olive by-products for animal feed)
"A. Practical recommendations
7. Olive tree leaves and branches constitute a fodder of exceptionally high quality (which is higher as the proportion of wood is lower). It is recommended that the leaves be used preferably fresh, since their nutritive value is higher than that of leaves which have been dried or preserved by ensilage.
8. Separation of the leaves from the wood whenever possible is also recommended."
They usually burn it in Turkey too. Biochar might be an option, maybe?
Hope it helps!
I know an olive grower in Greece who says he has been growing leguminous cover crops and mowing them for mulch. He also mulches any leaves and sticks that are small enough. He said it's hard to buck generations of practice to the contrary, but that he is seeing results.
I have autumn olives and comfrey growing under my little olive trees to improve the soil. So far it seems to be working fine. I also mulched pretty heavily around them with wood chips. I’m in portland so your mileage may vary.
I have a few different varieties. They’re all from one green world. One is an arbequina. The second one is seascape. I believe the third is universal. They’re all doing great. I could post a few photo's but they're not very exciting. They've grown about a foot each year and I believe this is year 3 for them. The 2 ukranian varieties (seascape and universal) have a better growth habit. They shut down their growth before winter sets in. The arbequina doesn't seem to do that and gets a few new branches killed back a little each year. It makes up for it with pretty robust growth the next season though so it doesn't seem to matter. I've gotten a handful of tiny olives that were mostly pit. I read that's typical for young olive trees so I'm still hopeful they'll make something worthwhile in future years.
I can talk about my own experience on the subject of prunings;
Here in South of Italy it's also the usual practice to burn the olive prunings. Throughout Spring you'll see people burning big bonfires of prunings on their land. It hurts me to see such wastage.
It's been difficult to find another solution for our land though, as the family wants everything to look "neat", which means no dumping prunings in a big pile somewhere on the land. Neither is there any municipal garden waste disposal service, where it would at least be composed or something. So till now, our practice has been to save the thicker wood for firewood, and to burn most of the rest.
What I have also done is make bundles of prunings by cutting them into pieces of similar length, laying them in a pile, and tying them together. Be warned, this is a labourous process, but the resulting bundles are good for piling up and storing neatly on the land. I have also used the bundles as a windbreak to protect young plants while they're getting established or to mark the boundaries of a vegetable or plant bed.
Last year we bought a small woodchipper to try and turn the prunings into mulch for the garden, but soon realized that it could only process very little at a time and that it wasn't heavy duty enough for our needs (we have 50+ trees).
Fortunately, I got to know a local guy with a powerful wood chipper (cost €1700 he said) which he rents out. That thing can handle branches up to 2/3cm diameter, which is perfect, as we could want to save anything as thick as that for firewood anyway.
I am very happy with this solution, as with that many prunings you get a lot of woodchips! Perfect for mulching the young plants and trees we've planted and returning nutrients to the land!
Not much help on the woody waste after trimming, but in terms of leaves, you could use them as a food source or sell them as such.
Olive leaf tea is a nice drink, used to be drunk in Greece pretty commonly ( I don't know if it still is in most places). It's got a mild flavor, but you need to boil the leaves for 5-15 minutes, then steep for another fifteen. I usually do dried leaves for this, but fresh would do in a pinch. You can make it strong or weak, your preference.
Also, olive leaf tea shows some promise as having anti-histaminic properties if drunk regularly. A study done on olive leaf extract (which I suppose you could track down how to make, perhaps?) showed definite effects on histamine levels. The leaf tea wasn't mentioned in the study, but I read an interview with one of the researchers (haven't been able to track it down to give you the link, I'm afraid!) where he said that the leaf tea helped as well, but unlike the extract, it needed to be taken regularly and took longer to take effect. Considering that I have used this for this purpose, and it worked amazingly well, I'm willing to believe it.
So not surprisingly, you can find dried olive leaves for sale in areas that sell herbal or medicinal teas, too, so that might be a market you could explore, potentially.
Here in Andalucia flail mowers are becoming the norm for processing the olive tree prunings where there is space for a tractor to pass between the tress. The branches are heaped in a windrow just over a metre wide. A tractor with a flail mower attched then moves along the row smashing wood upto wrist thickness. Its a quick process and very cost effective. Our local farmer charges 55euros an hour but gets a lot done in that time. I believe using a flail mower is more cost effective than paying for the branches to be burned. The mulch created is not considered a significant fire hazard and if left where it lays greatly reduces errosion.