When it comes to water wise choices in the garden, at the heart of the matter is the condition of the soil. A heavy clay based soil will compact easily, become waterlogged and prevent air, nutrients and water from reaching roots. A light sandy soil will drain quickly and leach nutrients before a plant can use them. Both are a waste of water. One soil will hold too much water and probably drown your plants and the other will need more water, more often to keep the plants alive.
The good news is that they can both be improved by organic matter.
Organic matter improves the soil structure of clay based soils, enabling the soil to drain better and make it easier for the plants roots to grow. It improves sandy soil by helping the sand particles hold together which helps the soil retain more moisture and nutrients.
Generally speaking anything that used to be living. In the garden, composted green and kitchen waste, fallen leaves, animal manure (this has to be aged for at least 6 months to ensure it won't burn roots), seaweed, vermicast from worm farms, lawn clippings and peat are all accessible options for adding organic matter to your garden. It is also the reason the tree planted over some roadkill or a beloved family pet goes on to grow and thrive!
Organic matter when it has broken down as far as possible, becomes Humus (not to be confused with the chickpea based dip Hummus). Humus is a dark, jelly like substance that helps topsoil hold together, which helps prevent erosion. It also absorbs and holds up to 90% of its weight in water and provides nutrients for the plants to access. It is vital to soil health and water retention.
When you hold soil in your hand and form it into a ball, clay soil holds together and stays solid. Humus rich soil will form a ball but will crumble into pieces when poked with a finger. Sandy or light soils will not hold the ball shape or completely disintegrate when poked with a finger.
The best time to start adding organic matter is now and keep adding it. Small amounts regularly is ideal as it can easily break down and begin improving the soil. Chopping up larger items such as leaves and seaweed also helps to speed up the break down process. Just be cautious when adding grass clippings. Spread it thinly and mix it in to avoid hot, slippery piles of slimy smelly grass! Don’t use the grass clippings if you have sprayed for lawn weeds in the last 6 months.
If you haven’t got a compost bin, Bokashi Bin or worm farm – look into it. It is a great way of taking your kitchen waste and turning it into user friendly organic matter for the garden. Why pay someone to take it away?
Improving your soil is not only good for the earth, it is the most effective long term way of being water wise.
