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Planting olive trees
jackp
Posts: 43
Hi I recently cleared a 10 meter mature bamboo hedge as the roots were getting out of control and root barrier not an option .anyway all roots are now gone and the plan is now to buy and plant 6 mature pleached olive trees ,the problem is that the soil is thick clay with very limited drainage which isn't ideal for olive trees so Today I've cleared a trench of clay about 1.5 feet deep by about 2ft which was 2 tons that came out .I wonder if this is enough soil removed before going onto the next stage ..I was planning on getting a good draining top soil and adding in small shingle and at the bottom of the trench adding in bigger stones .would this be enough as it looks to me like the water can still build up on the remaining clay causing damage to the new trees? I was wondering about taking another 2 tons out but I will end up Having to buy much more topsoil .Its not my garden so options might be limited.the lady wants it all finished asap but is keen about olive trees .any thoughts about please .Thanks,jack
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Olive trees are grown on all sorts of soil here including heavy clay. The trick is to plant them on a slope or raised humps/berms to aid drainage. This would also help to avoid damage to the shallow root system from mowers, strimmers etc. If the area in question gets heavy rain, as you are thinking already, yes there is a possibility you have just created a big sump with the trench you have dug, for rainfall to collect. If you went for a berm arrangement, you would of course then need to consider where the excess rainfall from the berm drains to...
A matter of personal taste, but the thought of a preached olive horrifies me, what an awful thing to do to such a magestic and naturally rounded tree, but I suppose you could say that about any pleaching.
If the lady in question is keen on olives, couldn’t you persuade her to have a couple of nice specimens in large pots, and to choose a hedging/pleaching tree that is more suited to her ground conditions?
If she is determined to go ahead, and assuming her garden is sheltered and the trees all face south or at least get a fair bit of sun (otherwise they will likely fail anyway) I would certainly make the trench wider, 3ft minimum, as the shallow roots do spread around a lot. Ideally, then raise the soil level on top of your trench - a berm is basically a raised ridge with gently sloping sides, or make it a traditional raised bed edged with railway sleepers or similar. I wouldn’t bother with the gypsum as it’s a temporary measure at best. You can use any old stones/builders rubble to fill the bottom of the trench and then a mix of gravel, sharp sand and organic material to plant in. Maybe half gravel/sand to organic. Ideally, aim to get a total depth - filled trench + raised area - of around 3ft. Top dress with gravel, not bark or similar.
I think all you can do is warn her that her conditions aren’t ideal, but this is what you plan to do to give her the greatest chance of success... Or, as you say, walk away.
Hope that helps, good luck!
Either opt for smaller size plants or look at other options for more faster growing shrubs that do a similar job.
Just had the lady in question on the phone tonight the trench after a few showers has turned into a lake even though I had left it with some drainage holes obviously wasn't enough ,I wasn't sure what to suggest just yet as the problem seems to be worse than I thought .it seems as though it's also getting water run off from the neighbors garden as its on the along the fence and whole area in general appears to have heavy clay with very limited drainage.I was planning on going back next week to dig out more clay and place large soak away followed by good draining soil but I'm not convinced it will be enough as the trees would be planted close the fence as well near the neighbors clay soil .I wonder if all this could just be a waste of time
Not or sure I can add any more, but perhaps other forum members have some views or alternative advice?
I’d go for pleached hornbeam ... it doesn’t mind having wet feet in the winter.
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
When you don't even know who's in the team
S.Yorkshire/Derbyshire border
So I've now come to the conclusion that olive trees are not suitable .
I am thinking of suggesting pleached holm oak trees .they can grow in clay and will tolerate the wet to an extent .any thoughts about these ? Many thanks
As i said, hornbeam will cope with wet clay soil as long as it’s not totally waterlogged throughout the winter, and it responds beautifully to being pleached.
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.