help with my Plum + Cherry Tree

[Nubber]

Hi, out my back I have a plum tree and a cherry tree I bought from some pound-store a while back, both trees have been in the garden now for 3 years and I have a few questions regarding both if anyone can help, thank you in advance (I don't know the variety of them however)

Plum
3 years in the ground now, and I have noticed it hasn't really grown, first year it put out 3/4 branches, and since then it hasn't put anything new out and hasn't gotten any taller, however it has gotten a bit thicker. it produce two fruits in the second year, however they were tiny purplely red berries which fell off and were tiny.

1) is that normal, that it stops growing and putting out branches and thickening up ?
2) right where the tree comes out of the ground there is now 3 thickish trunks (correct word) not sure what the plant is though, however its all around the plum tree, and the leaves look the same as the plum tree, can anyone tell me what this could be please ?
3) these trunks I mentioned in question 2, I cut back today, will that damage the tree ?

Cherry
Same, as above in regards of the tree being in the ground 3 years, not grown, but gotten thicker. cherry tree produced 4 cherries in the second year, and 2 last year.

1) same question as the one regarding (1) for the plum
2) I notice 3 of the branches have flower buds on it, but no leaves, none what-so ever, but the other 1 branch is full of leaves and no flower buds is this normal ? and if not any idea what is wrong please.

(little update on my chilli plant I was so proud I grew) it has died, I was advised to put it outside and bring it in at night to "harden it off" but the plant has just wilted up and rotten away, so now I still haven't grown a successful chili plant in around 100 attempts

[Kirk]

Will start on the bits coming out of the ground, they sound like growth from the grafted plum, they could also be growth from the actual rootstock. Either option means they should be removed. Closer investigation may show the graft below the soil level, if so scrap the soil away now and later in the year (when it is dormant) dig it up a bit and replant so that the graft is above soil level.

It might be that the rootstock has been "growing" and so not growing the actual plum variety. Just seems doubtful to the extent described.

Do you recall the rootstock that the plum was on ?
Just one option is that it was one of the very dwarfing ones that are intended to grow a tree in a pot, patio tree I think they were termed. If so then it would not grow to any real extent and likely would just thicken up. The rootstock being what limits size if sort of ultra dwarfing then maybe 3 foot is the max and all it can do is thicken up.

Cherries do tend to flower on leafless branches then produce leaves. So half of that makes sense. Not sure about straight to leaf without flowers but without flowers it may as well have gone straight to leaf.

Same question on the cherry - what rootstock waws it, was it another "patio" tree ?

My suspicision is that they were a cherry and a plum variety of these very small "patio trees" and they willl remain at a around 3 maybe 4 feet tall. Likely the cropping will therefore be very restricted also

[Jay22]

Don't know anything about the trees other than to say we have a couple in pots and do ok fruit wise, but I never grow chillis outside, far too chilly up here I think. (Oh, no pun intended there)