Grow Your Own Magazine

We've had our Mirabelle plum tree for 3 years now ( bought as a 2yr old) and this is the first year its flowered...ALL 4 OF THEM!!!!!!

I was beginning to think we'd got a dud tree and was going to contact Marshalls.
Anyway the old guy next to us told me yesterday that it's developed a tap root.
Apparently the tree tends to grow very long new growth ( 5ft in our case each year) and no flowers.( It's on St Julian rootstock )
He's advised us to gently remove the soil around the base and chop through the tap root, placing a bit of slate inbetween to prevent healing.
Apparently we should have put an 8-10 paving slab, or similar, under each tree at planting to encourage the roots to grow sideways.
I've never heard of this before- an it's certainly not mentioned in any of the fruit books I've seen.
It's the second tree on our site thats done this that he knows about ...
Any advice is really welcome!!!

Thanks LJ- I'll have to guard those blossoms day and night for now then!!!
November it is then.....( I've got a copy of one of their fruit books-will read up on it)