Plum tree help needed

Plum trees can take a while to fruit. Don't feed it (them) as this will encourage growth instead of fruit. You don't say whereabouts you are, could you add your location to your profile please as this can affect advice given.

Hi Rustylady

Thanks for your reply,i live in Dunfermline,Scotland

If it's planted in open ground (therefore able to find all its needs) then lack of fruit is usually because the growing conditions are too good; too fertile and too moist - or you've been spoiling it.

Ironically, digging it out and chucking it back into the hole would probably make it fruit, because its powerful roots would be damaged and the shock would encourage it to fruit.

There used to be a technique called "root pruning", where a tool (spade) was driven into the ground in a circle at the edge of the canopy spread. This severed the roots and the shock caused the plant to fruit

Why does "shock" work?
Because a plant is programmed to grow as large and fast as possible while the growing conditions are good, in order to outcompete its neighbours in the forests.
Once the tree reaches a point where either other trees are competing hard for nutrients (or when the tree has exhausted any soil where it has been able to grow roots) then it switches to fruit production.
If trees didn't naturally have this genetic programming to keep growing as much as possible, they would rapidly be overgrown and overwhelmed by their neighbours.

The more usual way to stop growth and induce fruiting (fruits the next year) in over-vigorous trees is hard pruning in July.

FB,
That was interesting information.The plum trees are planted in lawn along with the 2 apple trees.I have never pruned the apple trees,one we've had 17 years ,it's a compact Katy and we get over 70 apples each year.i'll try pruning them hard this July and see what happens.The 2 Dobbies ones look quite pathetic so I may well just dig them out and replace them.Think I need to do some reading about fruit trees!

So they aren't growing or fruiting?

If they're not growing, hard pruning will simply kill them. I thought that you were complaining becuase they're growing and not fruiting.
Do they produce blossom?

Do you know the rootstocks?

If they're neither growing nor fruting: maybe you need to take a look at your soil. Perhaps there is a nutrient deficiency, or the pH is wrong.

How deep is your topsoil?
What kind of topsoil is it? - sandy, loamy? clayey? chalky?
What's beneath the topsoil and how far down?

A problem with the soil could explain the death of the pear and the cherry.

FB,thanks for your new reply.Not exactly sure of the rootstocks but the trees aren't big so i reckon they are some sort of dwarf.The one from gardenbargains is a very healthy tree,loads of branches and leaves,just no flowers.Think I'll just get rid of the other 2.Our soil is clay,it has been lawn for about 50 years but I have quite a big veg patch that has been improved over the years(17) and we always get a good vegetable crop.Maybe I'll jsu stick to apple trees as they seem to grow well.

I think that it's worth keeping them. Some varieties are naturally slow to start fruiting.
You mention Braeburn cropping well, but it is known for being a heavy cropper at a young age (sometimes so much so that it exhausts itself and crops only every second year thereafter) - that's why the commercial growers like it; they need trees to fruit very early in life.

I would try pruning half of the new shoots back to 2-4 new buds in July.
Only the new shoots, and make sure that you leave a few of them (keep the best placed ones).

I think that it has a good chance to nudge them into fruiting in the following season.

If you dig them out, you may end up with the same problem.