Apple tree - amount of feed

[possumgreenfingers]

Hi,

I've been reading the forums for a while but this is my first post!

I moved into a new house 18m ago and inherited a large apple tree. Unfortunately the ground around the tree is all paved and I can't get to the soil to add mulch or solid fertiliser.

I'm planning on buying some liquid gromore but I'm not sure how much of this I need to use - there's small gaps between the paving and I'm hoping the liquid feed will soak down through to the soil. The gromore I've looked at is by Doff and suggests adding 15ml of concentrate to 7 litres of water to cover 7.5 square metres.

Also, I've got a 3 year old peach tree which is planted under gravel and membrane and I'm not sure how much to feed this!

Any advice would be welcome!
Thanks

[zazen999]

Do you think they need feeding?

[FB.]

Do you know which variety it is?
How old it might be?
How big is it?

I would suggest extreme caution changing the soil balance which the tree is used to.
You might be unpleasantly surprised at what happens if you feed too much nitrogen - such as causing rampant growth which might even break the old branches with the sudden increase in weight, along with the possibility of a big reduction in fruit quality because the vigorous new shoots will steal nutrients from the fruits.

[boundtothesoil]

Unfortunately the ground around the tree is all paved and I can't get to the soil to add mulch or solid fertiliser.
Thanks

Following on from what FB says, if the tree is large then the horizontal spread of the roots away from the trunk may exceed the diameter of the leaf canopy. Roots will extend long distances in search of nutrients, hence may well be capturing sufficient from (better soil?) beyond the paved area.

With many crop species of plants, if only a small fraction of the root system has access to a good (sustainable) balanced, supply of nutrients this will provide the entire plant's nutritional requirements.

[FB.]

if the tree is large then the horizontal spread of the roots away from the trunk may exceed the diameter of the leaf canopy. Roots will extend long distances in search of nutrients

Yes, a tree will do its best to adapt to its environment, assuming that it is strong enough to make the adaptation (i.e. dwarf rootstocks are not very adaptable and usually need regular feeding).
If the tree reached a large size (how large is large?) then it probably isn't having too much difficulty finding what it needs and is probably on vigorous rootstock which allows it to take care of itself.

I once planted on medium-vigour rootstocks but they struggled to adapt to the shallow infertile dry soil here: the roots grew too slowly and were easily "robbed" and crowded-out by the roots of other plants nearby which grew roots into their root zone.
A switch to vigorous rootstocks (vigour equivalent to wild seedlings) gave them the competitive edge they needed and they now hold their own.

The large and fast-growing roots of the vigorous (or own-root, or seedling) rootstocks are very evident when I have to remove a plant because the root system is usually of much greater mass than the shoots. I've had to dig out a few unwanted hawthorns or hazels in addition to fruit trees and they were often more roots than shoots: the huge root mass being required to find what the tree needed in poor soil.

[possumgreenfingers]

Thanks for all the answers, very helpful.

I would estimate the tree is 20+ years old and stands about 15-20ft high. It grew quite a bit last year but only had about 12 apples in total, compared to well over 100 the year before (I understand last year wasn't very good generally).

[FB.]

If anything, the combination of strong growth and poor cropping will be made worse by feeding.

Failure to crop could be several reasons, such as poor pollination, unskilled pruning (especially tip-bearers - which includes Bramley) or it might be a variety which is known for biennial cropping (big crop one year, sparse crop the next).

[veggiechicken]

Following on from what FB says, if the tree is large then the horizontal spread of the roots away from the trunk may exceed the diameter of the leaf canopy. Roots will extend long distances in search of nutrients, hence may well be capturing sufficient from (better soil?) beyond the paved area.

I have an apple tree root that grows on the surface of the soil or just beneath it and extends some distance away from the tree itself. It "annoys" me because its just where I want to plant something else! If I remember I'll take a photo of it when I get back.

[FB.]

I have an apple tree root that grows on the surface of the soil or just beneath it and extends some distance away from the tree itself. It "annoys" me because its just where I want to plant something else! If I remember I'll take a photo of it when I get back.

Yes, I know what you mean. There's a cherry tree near me which has a superficial root which looks more like a horizontal trunk - the trunk of the tree is about 2ft and the root starts at full trunk thickness of 2ft, tapering to probably 1ft at the edge of the canopy spread (and several inches out of the ground)!

The root - of your tree or the cherry I mentioned - has found something very good there and because it is able to supply lots of nutrients and water to the tree, the tree has "invested" a lot of resources in making that root as powerful as possible. Quite possibly most of the tree relies on that root.
If you interfere with a big root like that, there's a good chance that it could kill the tree because the tree may have become so dependent on that one big root and its other roots may not be able to compensate for the loss of nutrient-drawing ability.

Also the death of such a large root might weaken the tree anchorage.

If, in future, you notice a young tree beginning to form a big, superficial root which will later cause a problem, it is better to deal with the root while the tree is young enough to recover and before it has invested twenty years of energy into a root as big as a trunk.