RECENTLY redesigned my whole garden and put lime chip down over
weedmat. I kept some of the existing plants - two roses, a lilac
and a small kowhai tree. I realised, too late, that lime chip is
detrimental to the plants and have now pushed the stones away from
them to ensure no more lime leaches into the soil. Will this action
be enough to save the plants? I used the lime chip around the top
of terracotta pots and grasses as well, to their detriment.
CHECKED with the technical representative at Dalton's, who produce
much of the lime chip available in garden centres, and he confirmed
my own opinion. Lime chip is made from hard rock which does not
break down or dissolve readily and generally has no effect on the
soil. It's quite a different material from the garden lime you buy
to raise soil pH.
However, when you first
buy lime chips there can often be quite a lot of fine lime dust
covering them, and this could possibly have a slight effect on soil
pH, but should not cause serious problems.
The best thing to do
is to rinse the chips before using them around plants to remove
any dust. I don't think it likely your roses, lilac or kowhai will
suffer any ill-effects.
I'd be surprised if
lime chips would have had a seriously detrimental effect on your
grasses in the terracotta pots. Grasses do generally prefer slightly
acidic soil, but they also have a great tendency to dry out in containers,
and terracotta pots can dry out very quickly.
While a mulch of pebbles
or chips can be useful in helping to keep in moisture, it can also
give you a false sense of security as you can't actually see how
dry the mix is becoming. I've fallen into this trap myself. It could
be your grasses suffered from lack of water rather than from the
Gardener, Issue 165, 2005, Page 24
Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.