Using wood-ash in the garden

In Australia, it is currently summer (rather obvious to those who’re here, but it’s important to point this out). I am in the process of growing tomatoes and they are very nearly ripening but are being attacked by all manner of small insects. Now, typically I don’t mind insects and prefer a rather small-scale version of biological control (read: letting the Ladybirds and insectivorous birds do their thing) to applying pesticides. I’m not overly bothered by holes in silver beet leaves, or a few chew marks on my lettuce. Despite this, the ravaging of my tomato plants is becoming concerning and I’ve heard interesting anecdotes about using wood-ash as an insect deterrent and thought I would give it a try.

Essentially, the idea is that wood-ash contains calcium, potassium, magnesium and a bunch of other trace elements that gardens (in general) love. In terms of insects, it is typically applied on the soil in a ring around the plant to deter snails and slugs. Now, I don’t have a snail and slug problem – but I’ve noted this for future use. Instead I sprinkled wood-ash over the leaves and fruits of the tomato plants to deter flying insects. Wood-ash deters insects by drawing the moisture from their bodies. The ash loses any deterrent properties when it gets wet (hence the importance of summer).

Whilst researching this, I found some other anecdotal information about the benefits that wood ash can have on the garden. These are things that I will try out as it not only provides an organic/non-chemical alternative to pesticides but it also requires me to buy less, and recycle wood-ash that would otherwise have no use. The uses for wood-ash include; enhancing compost, algae deterrent adding essential elements to the soils and as a fertiliser (although I think the latter can remain anecdotal for now).

I will note the effectiveness of these methods and, if successful, will build a storage container that I can put wood-ash in over winter to use on the garden in spring and summer.