Alex Woodward wrote:
Any ideas what the ideal proportion of nitrogen, phosphorous and
potassium is for heaths and heathers. I've just purchased a soil
testing kit, but it seems pointless testing the soil if I don't
know
the levels at which the plants require their nutrition.

I've got the ph levels just about right now, but am unsure about
what
level of nutrition I should be aiming for. The first test shows
that
nitrogen levels are pretty low. I think that is supposed to be good
for heathers - am I correct?

To be honest, I'd ignore the whole thing unless I was conducting a
controlled scientific experiment for some purpose. If the pH is about
right for the ones you've got, just let the little devils rip in
their own way, and they'll love you for it.

Heaths and heathers occur naturally in rather poor environments, and
require low levels of nutrients. Feeding them could result in weak
sappy growth, when you want long-lived rugged specimens with short
legs. You could set fire to the lot every few years if you wanted to
reproduce their native habitat: not very horticultural, but it would
release some potash, and the local grouse would be grateful for the
new shoots! As you suggest, I _certainly_ wouldn't give them nitrogen
if they're growing in anything vaguely resembling soil.

The only time I'd consider actually feeding heaths and heathers would
be if they showed clear signs of a specific nutrient deficiency. And
I've never seen that (the books will tell you when). My best ericas
have been in a bed consisting of mixed builder's rubble (to include
bits of plastic and the odd end of Tanalised timber), Matchbox toys,
a few coins, limestone chunks, and shale fragments stuck together
with a bit of clay, and not much more. I watered them occasionally in
their first year, then let them get on with it: I don't live there
any more, but they're looking good up to twenty years later.

The NPK is best saved for the vegetables and the shorter-lived
flowering plants -- especially the ones we cut for the house, which
of course involves taking something away from the soil.

Plants want to grow, and they know more about it than we do. Amateur
soil-testing kits are a waste of time and money.

--
Mike.