The MGS Forum
Gardening in mediterranean climates => General Cultivation => Topic started by: helenaviolet on November 18, 2013, 12:39:51 AM
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I haven't actually tried this method but it could be worth experimenting with. If you are able to strike cuttings from whatever tree or shrub then, in theory, 'deep planting' might be effective, particularly if the plants have outgrown pots and you have long lanky saplings with a crown of leaves on top.
Contrary to all we have been told about planting out at the same soil level at which the plant was growing, you dig a deep hole and drop it in, leaving a nice 'leafy' top above ground. Here is a link to a fact sheet on the subject by Gardening Australia.
http://www.abc.net.au/gardening/stories/s2748866.htm
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Helena,
Thank you very much for starting this topic.
Apart from the specifics, it reminds us to challenge our beliefs and automatic practices from time to time.
As with many things, deep planting has its scope, outside which it does not work as well. But within its scope, it has merit. I think the trick is knowing how to apply the knowledge: appropriate soils, plants and climate/watering/time of year.
If my big Jacaranda cuttings (http://www.mgsforum.org/smf/index.php?topic=1578.msg10889) take root, they will need to be planted deeply - to keep them firm in windy conditions. In our Mediterranean climate, my concern would be that such deeply-planted cuttings would need regular deep watering - because it takes some while for the winter rains to penetrate deep into the soil - and I would not want the deeper roots to die and cause the bottom of the stem to die as well, since that would defeat the purpose. That is manageable, by using a perforated watering tube as deep as the cutting; it just needs that bit of consideration.
'Watering tube' explanation:
I plant all my trees with a near-vertical 50mm diameter rigid plastic tube going down to the base of the roots. I drill small holes along the lower half of the pipe, to allow the water better access to the soil. An irrigation outlet goes in a small hole near the top, and the top is capped to exclude creatures and debris and to reduce evaporation. The tube can also serve as a place to apply fertilizer and insecticide. By perforating only the lower half, weeds get less benefit. When measuring the tube for cutting to length, allow at least 30cm to protrude from the soil, otherwise the top can get lost in groundcover/weeds. Eventually, when the tree is well established, the pipe can be pulled out with a twisting action (severing any small roots that grew through the small perforations), and the hole filled with soil.
(Paraphrased from my original comment on 'deep planting' here (http://www.mgsforum.org/smf/index.php?topic=1578.msg10889#msg10889).)
I would be very interested to hear others' opinions in principle and from experience.
Helena and I appreciate that experiments in this realm can take quite a while (years) to do.
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There is an interesting article on the "woody plant propagation by long cuttings" in The Plantsman, vol.9, part 2 June 2010 pp93-97. Not quite the same subject but may be of interest to those that would like to do something differently to propagate Quercus,standard roses, Oleander, Euonymus spp etc etc using long hard wood cuttings.
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There is another interesting article in the Plantsman (March 2011): 'Plant ageing and its effect on stem cuttings', see this link http://www.rhs.org.uk/Plants/RHS-Publications/Journals/The-Plantsman/2011-issues/March/w-Veg-propn
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Jorun,
Thank you for that link; very interesting.
I have referred to it in the Jacarandas topic.
Mike
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Some experience to pass-on from my sister, Valerie...
I should point out that she gardens in NE Scotland.
Nonetheless, there are some points of relevance in a mediterranean garden setting.
"Some years ago I tried a technique of ‘burying’ a tree to see if I’d get multiple trees. I had an alder about 6 ft. tall that had been in a largish pot for years too long. The branches had all grown to one side. I therefore dug a slanting trench and put the whole tree in after extricating the root from the pot. Soil was shovelled back in along the length of the tree and firmed around the four or five branches that now stuck vertically out of the ground. Two branches survived and are now growing as ‘independent’ trees. I’ve no idea what has happened under the soil to the roots, but I’ve got two reasonable trees compared to one awful looking specimen. I tried the same technique with some willows that had to be moved from their original location, very confident of success as they root so readily from cuttings – they all died.
Deep planting in this location [windswept, near the coast, NE Scotland] sounds to have a lot to recommend it as the bigger the root spread, the less wind rock there will be. Of course the proximity of rock to the surface in some parts could be a problem. Deep planting could help keep the roots moist when the ground dries out in summer."
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It sounds as if there might be a correlation between the age of the stem, both above and below ground level, and the success of the technique, i.e. the younger the better?
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My question would be: is there a danger the stems might rot below ground level?
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Alice,
I think that's a fair question.
When a normally-exposed stem/trunk becomes buried (such as with a cutting), yet it survives, there must be physiological adaptations that take place. Where burial is followed by death, presumably those adaptations did not occur, or pathogens took hold too quickly. One would expect different species to have different propensities to adapt. Adaptability may also depend on the age/vigour/light-exposure/etc. of the stems (as you suggest, JillS).
Maybe when you take cuttings, there is a shock that triggers adaptation. We know that wound sites can develop callousing as a precursor to root initiation. But if a shrub/tree is partly buried the trigger may not occur. ...Just thinking out loud.
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This procedure does not seem to be basically much different from ground layering, which, according to Wikipedia,’ has the advantage that the propagated portion continues to receive water and nutrients from the parent plant while it is forming roots. This is important for plants that form roots slowly, or for propagating large pieces.’
Maybe some scarification of a part of the branches that are buried could speed up the rooting process (I’m thinking out loud as well), like you do in air-layering; I have had success with that.
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Oh, I founded the same method with another background (see Digging holes with hammer, chisel and crowbar (http://www.mgsforum.org/smf/index.php?topic=1046.0)).
Normally plantroots need oxygen (see hydroponics) and plants are sensitive to cover their roots with too much soil.
But I oriented me on this considerations:
o My "soil" above the rootball are stones, there is no problem for oxygen to reach the roots.
o Soil is never dry to 100 %. Soil moisture runs in a gradient from 100 % at groundwater aquifer to the % humidity in the air over the ground. Therefore plants can grow in the deserts without rain. That moisture must be enough for my plants. And the deeper they are in the soil , the higher is the moisture in the ground.
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I believe deep planting with long stems is not a problem if the soil on the rootballs is loose soil.
Some plants are usually set more deeply (roses, clematis, Paonia suffruticosa,...) so that the precious refined variety subsequently formes roots and grow with it.