The age old M9 vs M26 rootstock question

[Lady BlackThumb]

Hi folks, newbie gardener here. Would appreciate some real life experiences from those of you how have grown on the M9 and M26 rootstock for apples.

Context: I've been watching a lot of Dave Wilson Nursery vids on high density backyard orchard culture (recommends regular trees you prune the heck out of) and the Ontario High Density Apple Orchard methods that recommend more precocious M9 rootstocks that you turn into a very airy spindlebush form.

I've got a tiny South-facing garden in Surrey, with a long raised bed space where I'm looking to squeeze 2-3 apple trees in the space of 1.3 X 3m along a trellis in some kind of freakish cordon/espalier/spindlebush shape (undecided, will probably be some kind of lazy amalgamation of those). The trellis/trees are not likely to get any taller than 1.5m to keep it all in arms reach. There be about 30cm deep new topsoil/compost mix in the raised bed but underneath is some pretty solid dark clay soil.

I'm looking to get a nice steady supply of apples throughout as much of the fruiting season as possible rather than a glut in 2 weeks.

For you folks who have experience with M26 and M9, what are the practical differences in terms of upkeep? I'm going to have to prune anyway and the trellis will be permanently supporting the trees, so in terms of cold hardiness (not that Surrey gets that cold), needing to water, is there a noticeable difference on those fronts?

I'm kind of leaning towards the M9 since it sounds like it will fit my space/ideas more, plus I want fruit sooner than later, but at the same time I worry about a rootstock that can't cope with winter/the increasingly freaky hot summers.

(I'm open to the M26, but does this mean I'll be pruning like a maniac every weekend during the growing season??? Or does this offer a tougher more independent tree that requires less babying? Then again I do have a fluff monster that would appreciate all the apple twigs....)

Would love to hear of all your practical experiences on the pros and cons of either rootstock!

[Bluenowhere]

I’m training espalier fruit trees, top wire about five foot high so I can reach on my allotment. They are Homebase/B&Q trees not fancy year one maidens from nurseries. Although I know the variety and rootstocks and picked tress with side branches in about the right place to train, they may not be classically perfect but I got a small amount of fruit last year, the second year after planting and they look pretty good to my untrained eye and have received positive comments, which I was happy with as I’d be waiting a lot longer for fruit or training if I’d got one year old trees.

The root stocks are m26 (Apple) quince A (pear) and st julienne (plum). They grow well to get established, haven’t minded snow or very dry weather even though newly planted and provide plenty of fruiting spurs but they aren’t difficult or arduous to keep under control at least at the moment. I basically just chop off the longer shoots when I notice them in the summer and prune the apple and pear again when dormant as a tidy up to shorten the new fruiting spurs as per my fruit tree book.

Should have said I’ve got two trees in about the same space as you have. I’d say if you are espalliering two will be enough, if you cordon you should be able to squeeze in three but obviously there will be more pruning.

[nickdub]

There's no simple straight forward answer to your question which would be true for all varieties of apple grown on all different types of soil. The best approximation to a full answer I can give would be to say that if you are planting a strong growing variety like Bramley in soil which is as good or better than a fertile garden type then I'd go for M9 - where as a weaker type like Cox planted in a poorish soil would be better on M26.

One thing to bear in mind is that if trees are growing too strongly for the space available then letting grass grow right up to the trunks will check them a bit. (Obviously don't do this to newly planted trees)

[Lady BlackThumb]

Thanks @bluenowhere @nickdub. It's very helpful indeed.
I'm looking at sweet varieties like Gala, Fuji, Scrumptious, Katy, Rajka, which from my look see seems to point at average to large/ vigorous types.

Can anyone share the watering expectations like are for M9/M26, say in the height of summer/active growing season? Is it a water-every-day-or-they-die kind of situation, or water every couple of days/ if you forget it's not the end of the world scenario? I clearly know nothing of tree growing, and most of the articles I've seen tend to refer to larger trees that are grown in a more orchardy/ big garden setting.

Disclaimer: I did read the other similar rootstock threads on here before posting this.

[Lardman]

I've watched those video from our friends over the pond, Id take them with a pinch of salt. 3 trees is pushing it slightly in a 10'x4' space you'd but I stuffed 5 into 15'x1' using espalier, cordon and double cordon so I should shut up

I've spent a few years experimenting with high density planting and pruning and I'm not convinced. I'd much rather a nice espalier or a row of cordons.

I have most of my small espaliers on M26's and they needed watering last summer at least 4 pints a day but I'm on nasty sand and it's the only year I've had to do so. I wouldn't be concerned about the difference between M26/M9 and as I've mentioned before you can always cut tree off but you can't make it grow.

You've all need to manage your expectation of a full season of apples and amount of fruit, my espaliers out produce the high density plantings hugely with better quality and larger fruit.

[nickdub]

On the whole I'd say plant fewer trees a bit further apart, as its easier to get good quality fruit that way - light and air are important to fertility and healthy growth - as long as you don't mind doing a bit of trial and error work you can always graft a new variety on to one of your existing trees later to form a branch or two of a new sort on the same trunk. Another thing is that until trees get to the HUGE stage, you can always move them in the winter to a new spot with relatively little problem.

As for watering, always water newly planted trees in the first summer say once a week give them a real soak unless the weather is v wet. Apart from that I never water mine, unless I see a prolonged drought in progress and then only if they have lots of fruit which I want to be larger - around here that happened last year in late July and early August. But that was only the second time in about 35 years of growing tree fruit.

[Paulieb]

I have 4 rows of cordons in a field. There are a mixture of M9, M26 and MM106, and every one is a different variety, also Quince C and A for the pears.

As you can see I'm not great at controlling the grass, but find that most perform well. I don't notice too much difference between each rootstock, except for a Belle De Boskoop on MM106 which seems to outgrow everything else.

Watering, I watered once a week for the first 2 months (they were planted in Feb/Mar 2014) but never since.

I fed with Growmore (top dressing) after 12 months, but not again.

Pruning times are probably 5 minutes per tree in the winter, and 5 mins per tree in June (and for some 5 mins again in August).

The M9s were spaced 2ft 6ins. The M26 and MM106 were spaced 3ft apart. A few are getting to the top wire after consistent cordon pruning, largely meaning taking off two thirds of the main leader each year. I think I get a good crop, some started cropping in their second summer, most in the third summer.

Might try to get a better pic later as going to the field today to do some grafting.

[nickdub]

Hi Paul,
That's a very good looking setup you have there - plenty of space between the rows which always means healthier trees. As you commented yourself there's too much grass up to the trunks of the trees for best production, but on the other-hand less growth means less pruning, so less work.

All the best, Nick

[Lardman]

Don't leave us hanging like that Paulieb...I demand more pictures

It's probably just me but there's something appealingly organised about rows of cordons and so much room to put even more rows in. I'd be interested in the yields you get, are they all desert or are there cookers in there too?

[Lady BlackThumb]

Such brilliant insight from all of you. Ha, this is the thing I'm starting to notice is both frustrating and exciting about growing things: there's no "plant this on X date and X spacing and you will get an exactly Y sized tree with Y amount of fruit". 

Now I have to wait another 6 months before all the apple varieties on rootstocks I want is in season again! (Hnnngh the impatience of wanting instant gratification)

@lardman @paulieb I concur with the love of seeing neatly laid out fruit cordons/espalier. I hope to get my setup growing as nicely as yours! (And hopefully with more than 4 apples per tree in a few years time 藍)

[nickdub]

I always say that gardening is a bit more like cooking than it is like a scientific demonstration - and you can add in to that that the weather is usually different year to year.

[TrixC]

Personally I’d always rather choose a more vigorous rootstock and control the size through pruning, rather than a very dwarfing one where the tree may not thrive unless growing conditions are optimal. I have heavy clay soil so my trained apples are on MM106, pears on Quince A.

[Kirk]

Have grown both M26 and M9 and really little advantage to either.
I would maybe think of M9 in slight preference to M26. Sort of 55/45 bias.
If you want fruit then M9, bit bigger and will support and produce more fruit, rather simply more tree to grow fruit on.

[FB.]

An interesting thing I've found with M9 is that if grafted with a triploid, it starts out relatively dwarfed but eventually the triploid takes control and overrides the rootstock so it becomes vigorous.

In my conditions (dry, low-fertility) I find M9, M26 and MM106 tend to cause the scion to suffer severely from bitter pit, to the extent that I have now removed all such trees.
I now only have trees on MM111, M25 and B118.
In my conditions, M25 in particular seems to give scions good resistance to bitter pit, probably because the vigorous roots can gather exactly what the ripening fruits need, unlike dwarf roots which are either too slow-growing or have restricted sapflow at the graft, either of which might cause nutrient deficiency in the scion.

Personally, for good soils I would choose weak-growing scions on strong rootstocks rather than strong-growing scions on weak rootstocks. Grass all the way up to the trunks can be used to reduce vigour, too.

[Lady BlackThumb]

FB, does that mean bitter pit is something that can be fixed via watering? Also, fascinating info.

On a side note, say I got an apple tree on vigorous rootstock that grows to like 4m tallxspread, but I only have space for something 1.8 x2m, could I keep pruning it to that smaller size for the rest of the tree's life? Or is it going to end up an unbalanced monstrosity with a main trunk the width of an elephants thigh and small skinny branches from all the pruning in about 10 yrs? Or does the pruning keep the main trunk and root system proportionate to the size of the tree?