Spacing for M25 apple and other fruit trees - advice please.

[marchogaeth]

We've got the following coming.
Lord Derby - Apple Tree Rootstocks M25
Bramley Apple Tree Rootstocks M25
10 Cider Apple Trees M25 Rootstock
Victoria Plum - 2 year old
Damson Merryweather - 2 year old
Green Gage - Rheine Claude de Bavay

The cider trees are to be "wind breaks" for each other and around the others on the north (windy) side of the polytunnel, if that makes sense. I explained my site here Marchogaeth
There is plenty of space, so how far apart should they be planted do you think?

We went for M25 for vigour and because we like big trees but also we hope to prune them like the old orchards in that sort of umbrella frame shape.

PS I did post this as part of another thread but it wasn't picked up so sorry if you've seen this already.

[northepaul]

You do realise that M25 is a very vigorous rootstock?
Its orchard size?
I am just asking as you mention they will be in a polytunnel? Or maybe I misunderstood?

[FB.]

Spacing for the plums would depend on rootstock - Brompton/Myrobalan/St.Julien?

The spacing for the M25 trees would depend very much on the depth and fertility of the soil - and on what lies beneath (presumably rock - but how far down can the roots go?).

.

In the absence of complete information, I would work on a spacing of about 4metres for the plums (assuming St,JulienA) and about 6metres for the apples. If the plums are on Brompton or Myrobalan, they would be better at the same 6m spacing as the apples.
That could change considerably based on the soil, its depth, fertility and what is under the topsoil.

If the topsoil is shallow, with impenetrable rock only a foot down, you may find that big M25 trees will not be able to anchor sufficiently to support a big canopy without the trees leaning or being blown over in a storm.

[FB.]

I should add - for the benefit of anyone who dredges this up from the archives in the future - that I would not recommend the above spacings in *every* UK location - just the one we're talking about here!
Each locationwill have its optimum spacing, based on soil type, soil fertility, soil depth, soil pH, amount of rainfall and the variety grafted.
In my very poor, dry soil, Bramley on M25 could be spaced as closely 4-5 metres. On some very good soils it could be 7-8 metres.

[marchogaeth]

You do realise that M25 is a very vigorous rootstock?
Its orchard size?
I am just asking as you mention they will be in a polytunnel? Or maybe I misunderstood?

A wind break around the polytunnel. Sorry if that's not clear.

[marchogaeth]

Thanks so much for the input, it's the best advice I've been able to find since books all seem to steer away from even quite general guidance. For completeness:-
The plums etc are on JulienA.
The top soil is about 6" deep - pH 6.5 to 5.
Then there is approximately 12" of very clayish sub soil before hitting clay proper.
The field I'm looking at doesn't have rocky out crops so it could be as much as 10' before there is a rock layer. We do have some seriously big sycamore/ash/oak trees in the boundary (I know - I have no idea how long they've been around) and we are not prone to having big trees uprooted in even quite severe winds - they do all lean away from the wind in their canopy but the trunks are straight.

[FB.]

Thanks so much for the input, it's the best advice I've been able to find since books all seem to steer away from even quite general guidance. For completeness:-
The plums etc are on JulienA.
The top soil is about 6" deep - pH 6.5 to 5.
Then there is approximately 12" of very clayish sub soil before hitting clay proper.
The field I'm looking at doesn't have rocky out crops so it could be as much as 10' before there is a rock layer. We do have some seriously big sycamore/ash/oak trees in the boundary (I know - I have no idea how long they've been around) and we are not prone to having big trees uprooted in even quite severe winds - they do all lean away from the wind in their canopy but the trunks are straight.

Based on that info, I'd go with my original estimate of about 4metres for the plums and about 6metres for the apples. The Bramley - and any others known to be well-above-average-vigour might benefit from an extra metre spacing.

Almost all fruit trees will continue to grow slowly for their whole life. If left unpruned for 100 years, the Bramley might reach 10metres or more. If professionally and regularly pruned, it could be kept surprisingly small. So to some extent, they are a blank canvas for you to put your mark on.

To prove a point that it is the owner's skill which determines a trees size, shape, productivity, health and lifespan - I have actually been planning to grow a vigorous, tip-bearing variety on M25 rootstock, as a cordon or minarette.
I intend to do this, because "by the book", it is supposed to be impossible but I know that it isn't.

[FB.]

If in doubt, you could always plant at a slightly generous distance and if, in several years time, the trees are too slow-growing to look like they'll fill the space within 15 years, you could then consider planting in-between trees on a suitable-size rootstock to fill the space.

Sometimes, you just have to gain knowledge of your conditions from trial-and-error.

Alternatively, see how big similar fruit trees are getting in your area and work from that.