Patio Plum Tree

[Freedomlass]

Hi all, I'm new to this site and to tending to the garden fully on my own now, 2 years we (late hubby and myself) got 5 patio fruit trees, no idea on the all varieties as he had a habit of removing name tags, we didn't expect to get anything last year being the first full year but thought they would be good this year, the Bramley is doing well with plenty of fruits, the eating apple, pear and cherry all seem to be thriving but no signs of any fruits, however the plum is dead, I've done the test of rubbing the branches to see if green underneath but they aren't all brown and crumbly, early in the year it start to show the little growing buds but that's as far as it got, if I break one of these off it crumbles and resembles rust, can anyone tell me why this has happened considering all the other seem fine, they are all in their own individual large pots but all in the same area of the garden, when it came watering etc. I treated them all the same at the same time, I want replace this but don't want this to happen again if I get another plum or I may get another different one first, could there be something in the soil? would it happen again to whatever tree I replace it with?

Sorry for all the questions but I am still trying to learn all this but thank you in advance.

[ameno]

First, check the trunk carefully for any patches of bark which are sunken and tight, and which encircled the trunk. If there is such a patch of bark, while the bark above and below look relatively normal, then that's a sign that the tree caught dieback, which is a fungal infection that Prunus species are prone to. It infects the bark and kills it, and if it kills all of the bark in a circle the the part of the tree above the infection will also die.
It normally only affects single branches, but in rare cases it can get into the trunk and kill the whole tree. It happened to me this year with a seed-grown peach tree of mine.

If it's not that, next find the graft union on you dead plum tree (it's the place where the top variety was attached to the rootstock variety. It will be a bulge 1-5 inches above soil level, and the bark above and below may look slightly different). Do the scratch test on the trunk below the graft union and see if that is still alive.
That's the best thing to test next, as Prunus trees (plum, apricot, cherry, peach) are more prone to seemingly random graft failure than other trees. For some reason, the rootstock just rejects the grafted material, even several years after the graft was originally made. If the rootstock is still alive but the top is dead, then the graft failed. This happened to me once with an apricot tree.

If the rootstock is dead as well then the next thing to check are the roots themselves. Turn it out of its pot (I assume it's in a pot? You do say it's a patio tree), and first check for the above mentioned sunken bark girdling on any of the below soil-level section of the trunk. If there is none, next check the soil in the pot for any signs of larvae eating the roots (potted plants can be prone to vine weevil larvae, which are white grubs with a yellow-brown head, about 1cm long).

If it's none of those, I don't really know what to suggest.
However, whatever the cause, as long as you don't plant a new tree in the same soil as the old one died in (and as long as you wash out the pot well if you use the same pot), then a new tree is very unlikely to fall victim to the same thing which killed your old one.

[Freedomlass]

Thanks for the reply, the first two suggestions I have already done and checked and neither of those things were evident so it will have to be the roots to check next which I will try to do tomorrow, and yes it's in a vary large pot, I do have a new tree on order but decided against another plum but thankfully I do have new bags of soil/compost left over from other garden work I've been doing hopefully enough to replace what is needed.

[Snoop Puss]

No extra advice to add, but hello and welcome, Freedomlass. Good luck with your replacement tree.

[Jungle Jane]

Welcome to the forum Freedomlass It’s good to keep the name tags of your trees indoors away from the tree,otherwise it makes it easy for a thief

[Freedomlass]

Thank Jungle Jane but they would struggle to get these out of the back garden