This Season's Tree Losses

[FB.]

This season has been my worst ever. The long cold winter - the worst that I can remember in this area - combined with lots of snow and freeze-thaw cycles seemed to cause serious damage (and eventually death) to many of my fruit trees - mostly damaging them at ground level, where snow and ice would have thawed, wetted and re-frozen repeatedly.

The casualties, so far, amount to a large portion of my young-ish trees being grown as half-standards or standards:

Apples:

Annie Elizabeth, M25 (rootstock crown rot)
Ard Cairn Russet, M25 (rootstock canker)
Belle de Boskoop, M25 (rootstock crown rot)
Brownlees Russet, M25 (rootstock crown rot)
Jupiter, M25 (rootstock canker)
Norfolk Beefing, M25 (rootstock crown rot)

D'Arcy Spice, MM106 (rootstock canker)
Jumbo, MM106 (rootstock canker)
Suntan, MM106 (rootstock canker)

Discovery, MM111 (canker entered grafting scar)

........................

Pears:

Catillac (x2), Pyrus (canker entered grafting scar)
Concorde, Pyrus (canker entered grafting scar)
Conference, Pyrus (canker throughout the tree)
Hessle, Pyrus (rootstock canker, possibly crown rot)

........................

Now that is a bad year.

The surviving half-standards/standards, so far:
(which, knowing that my soil is difficult, I had been growing/keeping some of them in reserve, as a backup to such a disaster):

Bountiful, MM111
Court Pendu Plat, MM111
Court Pendu Plat, M25
Crawley Beauty, M25
D'Arcy Spice MM111 (x2)
D'Arcy Spice, M25
Discovery, MM111
Edward VII, M25
Egremont Russet, MM111
Howgate Wonder, M25
James Grieve, MM111
Spartan, M25
Tydeman's Late Orange, MM111
Worcester Pearmain, M25

No half-standard or standard pears survived.

.......................

Looking at the survivors of last winter's deep freeze, I note several things:

1.
MM111 rootstock (and my M9 or M26 cordons) tolerated the frosty/snowy/icy/freeze-thaw winter much better than M25 or MM106 rootstocks.

2.
I have previously observed that MM106 and M25 retain their leaves later in the autumn than the same variety on other rootstocks. Presumably, this means that a mild autumn that suddenly goes into a harsh winter (as last year) can mean that the trees aren't fully dormant.

3.
Only a few of the early-mid-flowering varieties on M25 survived.

4.
All of the very-late-flowering varieties on M25 survived.

5.
It may be that the later-flowering varieties on M25 helped protect the rootstock from the harsh winter conditions as a result of their longer and deeper winter dormancy.

6.
No pears on Pyrus rootstock survived, but my three Quince-A-rooted pear minarettes were unaffected.

[Hans Mum]

my quince which i put in Spring 09 didnt make it not sure what rootstock it was though.

[Nicos]

Flipping heck FB...that's a heck of a lot of trees

I thought we'd lost our Olive tree. No leaves on it at all- so we just stuck it in a corner...nothing.

And then just a few weeks ago we spotted some tiny shoots coming out ot the trunk about 3-6" above the soil level.

Phew- thank goodness- but such a waste of the wonderful 7ft growth of tree it had been previously.

[FB.]

The total number of trees seems a lot, but they don't grow very fast on my soil, so they don't need as much spacing as you'd normally allow. Also, many of the "heritage" varieties are quite small and slow growing. I presume that the heritage varieties are smaller because:
1.
They've picked up a few viruses over the centuries (although it is claimed that the reduced vigour of a virus-infected tree improves fruit quailty).
2.
Since our ancestors mostly had seedling rootstocks (quite vigorous), it was probably useful to select varieties that didn't grow as strongly, to make picking easier.

Due to my poor soil and slow growth, I plant at about two-thirds the normal distance apart, so I get about twice as many trees in the same space as other people might.

[hailtryfan]

Sorry to hear you've lost so many trees. Out of interest, do you know of any practical methods to protect young apple trees against damage from the cold?

[FB.]

Sorry to hear you've lost so many trees. Out of interest, do you know of any practical methods to protect young apple trees against damage from the cold?

There isn't much you can do, although mulching might help a litte.
Besides: fruit trees should be fully hardy.

I think that last winter was just plain bad luck - it was such a bad winter that any young fruit tree would be at risk of problems.

I think that the real killer for my trees was that we had snow and ice on the ground for weeks, but it would partially melt in the daytime and then re-freeze at night. It would have made the ground very wet for long periods (similar effect to waterlogging) and the soft, young bark wasn't yet thick enough to resist the frost damage, the saturated ground damage and subsequent fungal attacks.
We also had many late frosts, after the trees had come out of dormancy, which is not helpful.

If extreme winter troubles you, I'd look at M26 and MM111 rootstocks, which seemed virtually unaffected, unlike the MM106 and especially M25 rootstocks, which were badly affected.

[BeatTheSeasons]

Sorry to hear about all that, F.B. Although I'm in Cambridge we were overseas from mid-Jan until the end of May so I didn't fully experience last winter. We didn't have any young apple trees, although a young Brown Turkey fig in a pot survived outdoors. Weather never seems quite as bad in the City as is forecast for the rest of the County.

But all this does make me wonder how people grew apples in years gone by. Ok so 2009-10 was a bad winter, but really on a par with many years before about 1995-96, the last cold winter before everything started warming up. And if you go further back then you have a year like 1962-3 when the temperature stayed below freezing day and night for 6 weeks. Not to mention the severe winters which were a regular feature of the last few centuries - for example the Thames was completely frozen for two months in 1683-4.

Have apple trees gone soft? Is it the modern rootstocks? Have we raised our expectations now that we can grow tomatoes outside?

[hailtryfan]

If extreme winter troubles you, I'd look at M26 and MM111 rootstocks, which seemed virtually unaffected, unlike the MM106 and especially M25 rootstocks, which were badly affected.

I've recently ordered 10x M26 rootstocks for grafting onto next year so I'm glad they come with your recommendation

Have apple trees gone soft? Is it the modern rootstocks? Have we raised our expectations now that we can grow tomatoes outside?

Probably the case that young trees have always been more suseptable to harsh conditions than large established ones. I'm hoping that global warming dosen't shut down the Gulf stream in which case I'll need apple trees that grow well in Calgary.

[FB.]

Have apple trees gone soft? Is it the modern rootstocks? Have we raised our expectations now that we can grow tomatoes outside?

Yes, apples have "gone soft". Yes, I believe that the problem is that we're growing too much of the same clone.

Nowadays, fruit trees are dosed-up with chemicals to keep them healthy. Just read a book on fruit growing and it'll say "spray this, spray that, spray again to control this, that ot the other".
Take the "modern" trees or rootstocks away from the nursery and the chemical protection is no longer available, so the trees are at greater risk of problems.

I don't have many problems with my "heritage" varieties, since they have excellent disease resistance.
Rootstocks are more of a problem, since they don't necesarily have much disease resistance - especially when young or under stress of harsh winters.

I am led to believe that the "new" M116 rootstock is being introduced because many growers are finding that other rootstocks are too prone to root cankers/collar rot - which is exactly what I've been finding.

Although rootstocks (M25 in particular) are giving me terrible problems, I suspect that it's partly because they've been around for a long time and the nurseries have become full of diseases that have adapted to the same old rootstock being grown year after year after year in the same spot - in much the same way as apple scab eventually adapts to attack the modern "resistant" varieties, or in the same way as bacteria adapt to bypass antibiotic treatments. In fact, if the diseases didn't have mechanisms to adapt to their host, the disease itself would become extint.

If apple trees were grafted onto seedlings, as was common in the past, each seedling rootstock is a genetic individual that the diseases might need a longtime to adapt to (by which time it would be big and strong enough to fight them off).

I notice that quite a few nurseries seem to be listing a lot less M25 trees this year. Perhaps I am not alone in my problems.

It is now my intention to allow an ungrafted MM111 rootstock to flower and fruit, and to take those seeds to grow my own seedlings for use as rootstocks, in the hope that at least some of them will have MM111's resistances; the seedlings should have some similarities with MM111, but with natural variation sprinkled in, to keep the diseases at bay while the tree establishes.

[hailtryfan]

Yes, apples have "gone soft". Yes, I believe that the problem is that we're growing too much of the same clone.

I don't have many problems with my "heritage" varieties, since they have excellent disease resistance.
Rootstocks are more of a problem, since they don't necesarily have much disease resistance - especially when young or under stress of harsh winters.

I've only recently started growing apples and had previously presumed that the modern varieties developed for disease resistance are an improvement over heritage varieties as far as this is concerned.

I can see how the lack of genetic variation caused by vegetative propagation of both fruiting wood and rootstock would lead to increased susceptibility to disease. For example, all English elms are clones of a tree brought to our shores in Roman times. This homogeneity means no English elms possess genes that provide resistance to infection by the fungus that causes Dutch elm disease and so are all fated to die back before reaching maturity.

The modern norm of growing apples on a small number of cloned rootstocks is definitely asking for trouble unless the gene pool is periodically enriched as you plan to do.

Good luck with your experiments.

[FB.]

Most of the modern varieties (or rootstocks) can be traced to just a small handful of parents. The apple gene pool has definitely shrunk as growers found themselves able to control diseases with sprays.

Modern varieties, as a rule, tend to be selected for growers and for their "shelf appearance" in the shop (flavour is not much of a consideration because you can't taste before you buy).
They are also selected for how well they perform under nursery or commercial orchard conditions - not for how well they perform under semi-neglected garden conditions.

New varieties are selected for having fruits that are large, smooth, shiny, thin-skinned, perfectly shaped, even sized, well-coloured and super-heavy crops.
No wonder the wasps and maggots love them too - big and colourful fruit attracts the pests, large bunches of apples allow pests to tunnel from one apple straight into the next apple without being attacked by predators (birds, earwigs etc) and thin skin allows easy entry for pests.
The commercial growers can control the pests with chemicals, but it's not so easy for the home grower.

"Heritage" varieties were selected centuries ago for their "survivability" under less-than-ideal conditions and for producing good clean fruits, albeit in lesser numbers or smaller sizes than modern varieties. There were no chemicals to protect them - the old varieties either got on with life, or they died and were rejected by natural selection.
The heritage varieties tend to have small, dull, rough, lumpy, relatively uneven-shaped fruit. They are often lighter cropping or more erratic cropping than modern varieties.
Less crowded amounts of smaller, duller fruits with thicker skins is going to be less attractive to the pests.
Biennial bearing of old varieties? So much the better as it upsets the pest's life cycle and reduces fruit size in the "on" years, making the smaller fruits less attractive.

For a "spray-free" "back-garden" "amateur" grower, some of the old varieties can be very useful.

The ideal varieties varies for different parts of the country, depending on the conditions and diseases in that area. My situation is relatively unusual in that the low-rainfall but poor soil make powdery mildew my biggest problem, with scab the secondary problem. In many parts of the country - especailly wet parts - scab is a serious problem and mildew less so.

The choice of varieties that I grow is somewhat limited to those that have good mildew resistance, moderate or good scab resistance and good pest resistance.

[FB.]

.....and the losses continue.....

I recently noticed suspicious bark, on the rootstock at ground level, on two more trees:

Annie Elizabeth MM106
Court Pendu Plat M25

I am beginning to notice the possibility of a common link: checking back through my notes, the rootstocks that are dying from crown rot were either originally sourced from one particular nursery in the South of the UK, or have been in close proximity of those which earlier succumbed to crown rot.

My suspicion is that I was sold some disease-carrying (but not showing symptoms) stock in the past, and now, after the disease has "incubated" for a few years, the stock is dying and it is spreading disease to previously-healthy trees.
This is especially likely, since, although my soil is poor, it is should not be (theoretically) particularly prone to the waterlogging that would normally initiate infection by the crown rot fungi.

My suggestion: be careful where you buy trees on MM106 or M25 rootstock.

However, I have never found crown rot on M9, M26 or MM111 rootstocks - of which I have a reasonable number.

[Mell]

.

Have apple trees gone soft? Is it the modern rootstocks? Have we raised our expectations now that we can grow tomatoes outside?

This is an interesting question as we are just coming out of the little Ice Age, it does beg the question why should trees be dying in a colder winter (for us) but one that trees would easily have seen every year until recently

[FB.]

In teh past, commonly used rootstocks for apples were the seedlings.
They tended to be very vigorous and even if they weren't resistant to a disease, they were usually so strong that they could shrug it off by simply out-growing it!
Many apple rootstocks were grown either from crab apples or the Russian variety "Antonovka". Both very vigorous and hardy.

Any seedlings that weren't tough enough would have soon died - perhaps before being grafted.

[Mell]

In teh past, commonly used rootstocks for apples were the seedlings.
They tended to be very vigorous and even if they weren't resistant to a disease, they were usually so strong that they could shrug it off by simply out-growing it!
Many apple rootstocks were grown either from crab apples or the Russian variety "Antonovka". Both very vigorous and hardy.

Any seedlings that weren't tough enough would have soon died - perhaps before being grafted.

Depends what you mean by past & where. Generalising about historical practises is always incorrect, and often wildly so.

Yes seedlings were used, sometimes, some places, but so were specific rootstocks for some considerable time. In many cases grafted fruit was not the norm only trees on their own roots, in fact this practise is still the ONLY practice in some parts of the world now.

"the past" isn't a term that can be used with any real meaning particularly in a bioarchaeological sense