What's happening to my apple trees please?!

twopenny

Two trees, one Brambley one SF Cox, bought 3 yrs ago and producing foliage and fruit.

But the trunk below the grafting is still of baby size where the trunk is thickening.

They are still supported at the moment but I daren't take the support away and in a gale or weight of fruit they may snap at this rate.

I'd be really grateful for any ideas. Should I try and dig up and replant lower, or leave and cross my fingers?

   

RAS

twopenny

Please don't plant them lower as the rootstock will generate new growth at the base which might overpower the tree. And you bought the trees on rootstock to keep them small, so there's also a chance the scion will root, rendering the rootstock irrelevant. You definitely don't want Bramley self-rooted.

Do you know what the rootstock is? As some need staking for life. I suspect the top one here is the Bramley and it's had something growing close to it which will encourage advantageous roots to develop and then die? Got a lot of that on my trees in the path-side bed in the garden. 

twopenny

Thanks ras. Theres a small forsythia and a small hydrangea about a meter away in real life. In the case of the cox there's nothing nearer than a meter and a half.
Maybe I should organise a permenant support to go in and support the lower half.
Annoying, came from what was a reputable nursery I've used for 30yrs but I've had a problem with all 4 fruit trees. They closed down due to covid age and ill health.
Tempting to remove and replace with pot grown ones from the garden centre that are a better shape from the get go. 

maxsteam

It looks fine to me. Maybe the scion and the rootstock were different diameters at the grafting time and it's only noticeable now. Both will keep growing. Yes, support will be worthwhile but the time when you should worry about breaking branches is when you have loads of fruit on a small branch. This is harder, but not impossible, to support.

An alternative is to prune the tree to keep it small but it will benefit from plenty of sunshine and it may need to grow above the fence to get this. The fence, however, gives you plenty of options for supporting the tree.

The graft should always be above ground level.

twopenny

The rootstock is supposed to be M27, small.
I looked at some on discount at the garden centre and similar had happened to them.
It's not a worry about the branches breakin so much as the trunk at the join as the tree gets bigger and fuller.
It has become a bit too shaded there as the whole was grown from scratch just 2yrs ago but it's been flowering and fruiting a bit because the whole garden gets very, very hot in summer. The ground stays reasonably moist by the fence and there is open ground behind.
Yes, the fence has been useful with the repeated storms we're having and both trees have been tied to support but allow some movement to encourage root growth.