I AM a great believer in using builders', or slaked, lime for various jobs in the garden.
This is the fine, very white silky stuff.
It's not always available at garden centres, where more coarse forms of calcium, such as ground limestone and dolomite, are always on sale.
So, every few years, I buy a big bag of fine, slaked lime from the local hardware store, and it is surprisingly cheap.
This fine lime can be used in the same way as the other forms.
It acts more rapidly to sweeten acidic soil, but it's not a good idea to apply it at the same time as high-nitrogen fertilisers, such as poultry manure or fish emulsion.
They definitely do not mix, usually reacting against each other so badly that any beneficial advantages of the fertiliser or the lime are lost.
This is why the best time to apply lime of any kind is in autumn, when few fertilisers are being chucked around.
However, I still use slaked lime for other purposes during the growing season.
Apple and pear trees growing in districts that experienced wet conditions in late November and early December will now be showing the adverse effects of such warm and moist conditions.
Two common parasitic fungal diseases, apple scab and pear scab, have struck hard in these districts.
Scab first appears on leaves that look blotchy and slightly wrinkled.
Then it moves on to the young fruit, beginning as a tiny black spot that spreads quickly, distorting the fruit.
Normally most leaf and fruit surfaces are slightly acidic; conditions loved by the scab fungus.
My method of control is to mix a couple of cups of slaked lime into a bucket of water and mix. The water turns white like milk.
This mixture can be sprayed over the foliage of vulnerable apple and pear trees and is an effective means of controlling the disease.
It works because it dries on the surfaces of the leaves and developing fruit so they become alkaline.
So the coating of lime acts as a powerful deterrent against scab, and it works brilliantly, even with the scab-prone apple varieties such as granny smith and pink lady.
Normally the first spraying should take place in late spring, but it is not too late even when the first signs of scab have appeared.
I should add that I'm patient enough to go over my apple trees picking off or raking up all scabby apples and carting them well away. The same lime spray is also an excellent way to control pear and cherry slug.
These are those revolting little slug-like grubs that graze away the green leaf surfaces of pear, cherry, hawthorn, quince and many Japanese plum trees.
They usually appear in mid-December and if not controlled will completely skeletonise leaves and seriously weaken the trees.
When the trees are sprayed with slaked lime and water, it causes the slugs to shrivel and die, often within a couple of hours.
Usually one spray is enough.
Spraying with lime also adds a little extra calcium to the soil and helps prevent bitter-pit disorder of apples, caused by calcium deficiency.
While spraying, the mixture should be constantly agitated because it tends to settle.
Afterwards make sure the spray gear is washed out and flushed clean.
There are a couple of other uses for slaked lime in summer, this time in the ornamental garden.
For the past three years, I have given my lilac trees a mid-summer drink of lime water. They love the stuff.
Since I started this treatment a few years ago the lilac leaves have become unusually large and are a rich, deep and very healthy green. And the spring flowering has been spectacular.
The other use has been with some of my hydrangeas.
Our soil is slightly acidic, so most hydrangeas in the garden form blue-coloured heads.
A big bucket of lime water applied to selected bushes in early January and again in autumn has turned the heads of these plants bright pink.
In fact one hydrangea now has soft-red flower heads; whereas a couple of years ago they were blue.
Just be careful when using extra-fine slaked lime. Avoid breathing in the tiny particles. Wear a protective mask if necessary.
And if you have a sensitive skin, be sure to wear gloves.
