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David Humphries

To Mulch, or not to Mulch?

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Thought I had this brilliant idea (mulching) sorted as a no brainer for a struggling tree but now I'm so konfoosed.

 

I have a mature but small apple in a lawn that's essentially come to a grinding halt: little new growth, stagnant existing growth, some deadwood (until 3 weeks ago) but still very much alive.

 

As well as deadwooding it in mid Feb I quite severely spur-pruned it as the crown was a tangled mass of fruiting spurs - far too many for a less-than-vigorous root system to sustain and indeed I was told that last year the tree produced a huge crop of small fruit, many of which dropped prematurely.

So I thought 'mulch it - can't go wrong'. But should I? I still think the tree stands to lose nothing by my doing it but how do I tell if it's the best thing? Does it make a difference what tree species of chip I use? I've got a supply of semi-composted mixed species chip waiting (I wouldn't use fresh chip after February) so I'm thinking I'm good to go.

 

I'm itching to give it a go as I still marvel at that picture of David H's Hampstead Heath pear tree in flower; for me it's one of A/T's finest moments.

 

Thanks,

 

Jon

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Yeah, that possibility had occurred to me Tony but the density of fruiting spurs could also explain that surely.

 

I think the long and the short of it here is that I'm unlikely to do any harm giving it a go. I'm just glad you didn't come back with 'no way'!

 

Thanks,

 

Jon

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Jon, I disagree with Tony on this one. The tree may well not be in terminal decline - I've sorted out my parents' orchard of semi-dwarf apples planted in 1919, over the past 25yrs. This started out as mis-shapen things with small fruit and a mass of spurs. Many of them are now fully back to reasonably decent shaped trees and only 5 have died in this period.

 

Left alone, I have no doubt that Tony is right, but with intervention apples and pears are some of the most forgiving trees going. They will, in arb terms, pollard (which would be described as re-heading), can be heavily retrenched by either gradual reduction to promote epicormic growth, or by drop-crotch pruning, depending on whether there are branches placed where you want them when you start, or not. You can decide that you don't like a particular variety and literally saw the top off of a 50yr old tree and re-graft it, with a good chance of success.

 

The one thing they do have, which is core to this thread, is a weak root system. Even on their own roots they're pretty small as trees go (compare David's pear with a fully mature beech, oak or ash for example), and man's intervention has deliberately bred smaller root systems for convenience of picking the fruit and increasing yield per acre. As such, it's not surprising that intervention is needed to maintain them, to a greater level than with a 'forest' tree. They need pruning to keep the sail area down and to maintain vigour, otherwise they go into senility and die. They can't compete with grass, for either water or nutrients, so it needs removing. If you leave bare earth you get rapid water loss and since they have a weak root system the trees will then either need irrigation or measures to enhance water retention, such as a mulch. Keeping weeds off can be done chemically, but mechanical methods will damage the shallow root system, so again a mulch scores.

 

Personally, I don't regard maintaining an orchard (or even an individual fruit tree) as looking after an ecosystem so much as deliberately altering one, just as any form of farming or gardening is. Hence, if you have issues with particular fungal species threatening weak trees, killing the fungi is a logical route (yes I have used Armillatox, about 20yrs ago with successful results where otherwise honey fungus would have ripped through the orchard. One of the previously infected trees is still there, quite healthy, with no fbs in the last 15 or more years). Yes I do want slightly enhanced nitrogen, potassium and phosphorous levels to promote increased vigour and yield over that which would be achieved if I didn't apply them. And yes, I do want a mulch as it's the best compromise available that I've identified to swing the odds in favour of the tree, which is the part of the ecosystem I'm most interested in.

 

Personally, I try to use unrelated species, or even straw mulches, to reduce the likelihood of any imported fungal species which specifically target the tree species in question.

 

I'm sure the above is contrary to the views of some, but it has worked for me.

 

Alec

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...Left alone, I have no doubt that Tony is right, but with intervention apples and pears are some of the most forgiving trees going. They will, in arb terms, pollard (which would be described as re-heading), can be heavily retrenched by either gradual reduction to promote epicormic growth, or by drop-crotch pruning, depending on whether there are branches placed where you want them when you start, or not. You can decide that you don't like a particular variety and literally saw the top off of a 50yr old tree and re-graft it, with a good chance of success.

 

The one thing they do have, which is core to this thread, is a weak root system. Even on their own roots they're pretty small as trees go (compare David's pear with a fully mature beech, oak or ash for example), and man's intervention has deliberately bred smaller root systems for convenience of picking the fruit and increasing yield per acre. As such, it's not surprising that intervention is needed to maintain them, to a greater level than with a 'forest' tree. They need pruning to keep the sail area down and to maintain vigour, otherwise they go into senility and die. They can't compete with grass, for either water or nutrients, so it needs removing. If you leave bare earth you get rapid water loss and since they have a weak root system the trees will then either need irrigation or measures to enhance water retention, such as a mulch. Keeping weeds off can be done chemically, but mechanical methods will damage the shallow root system, so again a mulch scores.

 

Personally, I don't regard maintaining an orchard (or even an individual fruit tree) as looking after an ecosystem so much as deliberately altering one, just as any form of farming or gardening is. Hence, if you have issues with particular fungal species threatening weak trees, killing the fungi is a logical route (yes I have used Armillatox, about 20yrs ago with successful results where otherwise honey fungus would have ripped through the orchard. One of the previously infected trees is still there, quite healthy, with no fbs in the last 15 or more years). Yes I do want slightly enhanced nitrogen, potassium and phosphorous levels to promote increased vigour and yield over that which would be achieved if I didn't apply them. And yes, I do want a mulch as it's the best compromise available that I've identified to swing the odds in favour of the tree, which is the part of the ecosystem I'm most interested in. ...

 

Excellent post--agrees with experience over here, and with a recent study in the AUF journal--mulched trees in both nurseries and orchards outperformed bare ground or mowing. What kind of mulch--can one go wrong by mulching with material similar to the subject tree(s)?

 

"...the tree, which is the part of the ecosystem I'm most interested in.

 

"...the tree, which is the part of the ecosystem I'm most interested in.

 

"..the tree, which is the part of the ecosystem I'm most interested in.

 

Thank you for reminding us of an arborist's #1 priority! :biggthumpup:

 

Aeration and attention to nutrients may be needed where diminishing soil oxygen and increasing (or decreasing) soil nitrogen levels are a concern.

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Just that one tree is a fantastic advertisement for you and your work - well done; what a beauty.

 

Total agree.well done dave

 

 

Sent from my iPhone using Tapatalk

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Alec The Apple - that's really helpful; thank you. I'm helped in this case by the fact that the tree has historically been well maintained so has a balanced and open structure; it's the mass of small stuff that was attached to it that was the problem I hope, caused by lack of management over the last 7 or 8 years I'd guess. I have probed a bit into the recent house occupancy but the place is split into flats so I think the tree's been lucky to have had any management.

As far as you can age a garden apple by looking at it (!) I'd say it was 40-70 years old; mature but by no means past it, not in terms of pure age anyway.

 

A-mulching I shall go.

 

Thank you all.

 

Jon

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The one thing they do have is a weak root system. Even on their own roots they're pretty small as trees go ... compared to a 'forest' tree. They can't compete with grass, for either water or nutrients, so it needs removing. If you leave bare earth you get rapid water loss and since they have a weak root system the trees will then either need irrigation or measures to enhance water retention, such as a mulch. Keeping weeds off can be done chemically ... I don't regard maintaining an orchard (or even an individual fruit tree) as looking after an ecosystem so much as deliberately altering one, just as any form of farming or gardening is ... used Armillatox, about 20yrs ago ... a mulch as it's the best compromise available ... the tree, which is the part of the ecosystem I'm most interested in.

 

Alec,

The root systems of apple trees and other cultivated fruit trees are associated with just a few of the generalistic and cosmopolitan endomycorhhizal microfungi, which implies, that - apart from some generalistic (necrotrophic) parasitic macrofungi - they are "loners" that don't have an ecosystem, let alone a tree species specific ecosystem at all. And that's why they can't compete with grasses and herbs, that have the same endomycorrhizal associates attached to their root systems.

So whatever you do chemically (herbicides, pesticides, fungicides, Armillatox) or by mulching and introducing nutrients to the soil, there is not much damage done to the soil food web, because it hardly exists in the first place.

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