| Don't be tempted to come back from an overseas
holiday with Lettuce seeds. They are totally prohibited in all states of Australia since
most Lettuce, Onion and Carrot seed grown outside Australia has a leaf virus which is
carried in the seed. That's why so much Australian seed is sold for export. Any doubts
ring AQIS 1800 018 318. If your plants are looking a
bit yellow on the leaves at present, it's one of two things. If the veins are green and
the yellow is on the rest of the leaf, that's lime-induced-chlorosis (LIC) and if it's
yellow all over that's a nitrogen deficiency. Both are common at this time of year on
local soil.
Now the lime-induced-chlorosis is often refered to as iron
deficiency or chlorosis. Our red clay soils are not really deficient in iron, it's just
that they get so alkaline that the iron is not readily available. We're not talking about
iron filings, since ferous iron is no good.
The very best remedy is a burgundy powder called iron
sequestrine, but it's expensive and hard to find. Next and most widely used is iron
chelates (pronounced keelates) and some folk use iron sulphate, but if your soil is a
heavy clay, the salt residue that remains can be a problem. Use chelates every other month
and all should be well.
My neighbour has a licence to grow tobacco. That's right
you need a license in South Australia! Anyhow his plants always look chlorotic to me so
I'm keen to dose them with iron chelates and see if they taste any better to him. With our
garden plants iron makes them healthier and the greener leaves make for better flowers or
fruit. |
