Apple Rootstock M25 and MM111 comparison pictures

[FB.]

For curiosity's sake, and topical considering the recent dry spell, here are a few of pictures of young apple trees which show the typical root structure.

Pictures 1&2: apple rootstock M25
Typically has half a dozen to a dozen quite thick roots with medium quantities of fine roots.
Drought tolerance is about average.
Roots don't have any special disease or pest resistance, but are not especially prone to problems either.
Prefers warm, slightly moist, slightly acidic to neutral soil (pH 6.25-7).

Pictures 3&4: apple rootstock MM111
Typically has a few fairly thick roots deep-down, and large quantities of fine roots closer to the soil surface.
Drought tolerance is well above average, as would be expected from the large quantity of fine roots.
Good resistance to root diseases and pests; works well in "replant" situations when replacing dead MM106 trees.
Prefers warm, neutral to slightly alkaline soil (pH 6.75-7.5).

[FB.]

-

Here are some sketched which I've posted before:

-

[seneca196]

I suppose an mm106 would look similar to the m111? Cricky, there's a lot down below. I can see why they need so much distance between them. Would that rule out planting in the vicinity? I had an idea of sinking some large pots between my mm106's so that I could fill the space in the border whilst lessening any impact regarding water and nutrition for the tree. I thought the mm106 roots would eventually grown around the sunken container and the 2 plants could co-exist in harmony!

[FB.]

MM106 looks more like M25 but its roots are smaller.

For reasons not entirely understood MM106 roots take several weeks to start growing again after a drought. In dry soils and low-rainfall areas this can mean that MM106 roots barely manage to grow at all.
On the other hand, M25 roots are very quick to respond to rainfall, with growth resuming and new green shoots appearing within a few days.
MM111 has a lot more fibrous roots and is more drought tolerant than M25 (and much more than MM106) and MM111 often can continue growing after M25 is no longer able to suck up water. In some very dry situations it can mean that the MM111 isn't much different in size to M25.
I think it's because M25 roots suck up water so quickly that they soon suck the soil dry and have to stop growing, whereas MM111 roots seem to form balloon-like reservoirs at the end of fibrous roots which slowly pump the water and nutrients up to the canopy. So MM111 I suppose stores it for later use and uses it at a slower rate than M25 which tends to use what it can find as quickly as possible.

[seneca196]

good to know FB. Here's something for you and anyone interested - I was wondering how your apple trees were situated in your garden? (I'm assuming you don't have an orchard or a vast field, though you certainly have quite a collection.)
The idea of spacing and planting in between, or putting trees into an existing border is something I've been thinking about recently. For those who can't dedicate a large space to a tree alone or put one in the middle of a lawn, for reasons of not disrupting an existing scheme, or purely a lack of space, how have they achieved this? I know isolation is the ideal for optimum growth and fruit production, not to mention health and quality of the tree/fruit, but there must surely be a way. Ok, it's not perfect, but those with no alternative other than to compromise, is it possible? One of the reasons behind my sinking big pots between trees. Books and websites say that for less vigorous rootstock the ground must be free from competition. However, more vigorous can tolerate some completion after a few years, when established. How have you found this with the various rootstocks you have used (I know you aren't keen on mm106, but thought you might know.)
Thanks.

[FB.]

I think if you sink big pots into the soil you'll have tree roots come up into the pot. You might also find the impeded drainage causes drowning or root rots of the potted plants.

M25 and MM111 are fine with other plants around them. I've often said: rather than plant a dwarf tree and have to take care of it, why not plant a vigorous tree and neglect it such that it behaves like a dwarf but without the care requirement?
My "neglected" MM111 and M25 (vigorous) trees behave like a "fully managed" M26 (semi-dwarf) tree. The dry summers, shallow/low-fertility soil and aphid attacks really slow them down.
I work on the assumption that my "neglected" (apart from a winter tidy-up prune) MM111/M25 trees will mostly reach a mature size around 2.5m (8ft) at 10-15 years which is about what "the books" say for M26.
In other words: treat a vigorous rootstock roughly and it'll behave like a dwarf. Treat a dwarf roughly and it'll wither away.

MM106 is a borderline case for competing with other plants. It will cope with other plants around it in areas of higher rainfall, but in lower-rainfall areas the grass or other plants may intercept the water before the slow-to-restart-growth-after-dry-spells MM106 roots get going.
That's the problem I have: MM106 is too slow to get going after a dry spell, so other plants get the water first and then comes another dry spell.
MM106 will grow just fine in shallow infertile soil if there is enough water; its roots are a match for MM111 where moisture isn't a limiting factor. But once MM106's roots are brought to a stop by dry summer weather, it's slow to restart again - unlike MM111 and M25.

I have no problems with maiden whips of MM111 or M25 planted straight into un-enriched soil with grass all the way to the trunk.
In fact, I think that apple trees perform better when grown in grass and given very little feeding or watering - healthier and more productive (as long as the rootstock can cope; M25 and MM111 are fine, MM106 is borderline, depending on soil moisture availability).
UK interactive historic weather patterns map here:
Met Office: UK mapped climate averages

Take a look at the annual rainfall data.
You'll see that here in Cambs we have quite low rainfall - about half the UK average - and the main factor in the growth of a tree is the availability of water (including good soil moisture retention or a cooler/shadier patch of soil which doesn't get so hot and sunbaked so stays damper for longer).

[FB.]

-

I've shown the following picture before, which was taken probably half-way through the summer a few years ago.
It's a MM111 whip, planted in shallow infertile soil with grass all the way to the trunk and only minimal care.
Despite semi-neglect and fierce competition it's happily getting on with life; growing several new 1ft long shoots to form its first branches.
New growth is plentiful signalling a content tree. The leaves are all numerous, dense, large, bright, clean and healthy which is also a good sign.

-

[FB.]

-

Some more interesting pictures.

Pic 1: M25 planted in grass, picture taken around the middle of summer.

Pic 2: another M25, different tree to above, picture taken late spring/early summer.

Pic 3: same M25 as above but picture taken a couple of months later, mid-summer.

Pic 4: M25 being grown as cordons!

[FB.]

-

One more picture (I'm limited to four per post).

This is a M25 tree which endured a severe aphid attack which damaged all its leaves and brought growth to a temporary stop.
It then fought back with a mass of new shoots (pale green).
M25 doesn't give up easily.

-

[FB.]

-

More pictures.....

1. Ten-year-old Laxton's Superb on MM106, originally planted in clear ground and mulched, suffering "runt-out" (it's probably 4ft in size).

2. A problem with planting varieties which are widely grown or descended from common varieties: fruit scab on Laxton's Superb.

3. Leaf scab on Golden Delicious - my tree always has messy leaves and sometimes some fruit splitting as LS above.

[FB.]

-

Yet more pictures

1. MM106 planted in grass, producing burrknots (above-ground roots) exposed when I pulled the grass aside. MM106 produces more burrknots than other rootstocks in my soil. The burrknots emerge from splits in the bark and serve as an entry point for canker or crown rot - their entry assisted by the humid/damp grass.
Burrknots seem worse where trees are lacking water (they try to grow more roots to find more water), and also where dense damp grass makes the lower trunk think it's under ground.

Picture 2: M25 Court Pendu Plat in its second leaf, planted in grass. Picture taken late spring.

Picture 3: MM106 lower trunks develops a "bone-like" appearance, with pale, smooth, hard bark below the graft after several years - and this seems to make it much more resistant to diseases such as crown rot. The original woody bark peels off.

-

[FB.]

-

More pictures.

Dwarf and semi-dwarf rootstocks such as M27, M9 and M26 develop abnormal-looking grafts. It is this abnormal growth which slows the sapflow and dwarfs the tree.

1. M26 is wider below the graft than above.
2. M9 forms a "flying saucer" bulge at the graft.

3. Triploid varieties on vigorous rootstocks (seedling, M25, MM111) can often recover from extreme damage. This century-plus-old tree is now on its second life. Maybe, like a cat, there will be seven more.

[FB.]

Last pictures for now.

A couple of old espaliers in a walled garden (join the National trust - it's worth it!).

-

The first one is a several-decade-old Blenheim Orange on MM106, possibly somewhere in Hampshire but might have been Bedfordshire.

The second is a similar-age variety on the same rootstock in the same location, but this one is a medium-vigour diploid and is in decline.

Triploids - especially the vigorous ones - stand the test of time well.




URL=http://s459.photobucket.com/user/fluffybuck/media/espalieroldderelict.jpg.html][/URL]

[seneca196]

Fascinating pictures FB. Your own ones are particularly useful. One of the things with attempting to grow a tree and choosing a rootstock is I tend to have a picture in my head and struggle to match it to a form and rootstock.Tricky trying to visualize the trees changes over the next 5-10 years. Fine if you can just plant and ignore them, but if they form a prominent border that will be kept bare so as not to impede their development, then they are very noticeable. Hence, I'm trying to think of a way to grow other plants around them and make them less noticeable. Visually they will be just one aspect of the border and not everything (being the only things in it.) Best I can come up with at the moment is to dot a few semi-shade shrubs in the gaps and have them just sit about in containers. If they can be fruit, mores the better, but not essential. Priority is the trees, everything else is an after thought for next year.

[orangepippin]

-

Yet more pictures

1. MM106 planted in grass, producing burrknots (above-ground roots) exposed when I pulled the grass aside. MM106 produces more burrknots than other rootstocks in my soil. The burrknots emerge from splits in the bark and serve as an entry point for canker or crown rot - their entry assisted by the humid/damp grass.
Burrknots seem worse where trees are lacking water (they try to grow more roots to find more water), and also where dense damp grass makes the lower trunk think it's under ground.

I would always advise against planting new trees in grass like this, especially long grass. It creates an unhealthy microclimate around the graft union, as well as competing very strongly with the tree when it is trying to get established. You might get away with it if the tree has a very vigorous rootstock, but far better to remove the turf to give the tree a better start.