spakker wrote:
I have got into gardening over the last two years. I am planning
some
re-building work and have put most of my plants into pots-upto
dustbin size. However I used B&Q type compost rather than garden
soil-some black soil but all based on heavy clay-to avoid weeds.One
or two years down the line many plants are suffering.I know
watering
is more required for pots , but I am begining to suspect that the
bought -in compost is not really upto the job. Any comments please.

The compost's probably exhausted: the nutrients they put in it don't
last long, and the compost itself won't have any food value. If you
start giving a regular liquid feed (Phostrogen or B&Q's own brand,
whatever's cheap), just follow the instructions on the packet and
your plants should perk up. As you say, plants in containers do need
regular watering.

If a peat-like growing medium has been allowed to dry out, it can be
very hard to get it wet again, and plants may not get enough water
even if you attend to them regularly. In that case, a drop of
washing-up liquid in the water will help it soak in; best to stand
the container in something for an hour or so to let water come up
from the bottom as well as the top.

Silly question, but just in case, and no offence meant: the
containers do all have good drainage holes, don't they?

Some of the plants may now need repotting in fresh mixture and maybe
a rather bigger pot.

--
Mike.