Soil and Organic Mater – The Why and How.

OK – so it is still early spring- and we are itching to get into the garden.  One thing you will here most good gardeners talk about is working ‘organic mater’ into the soil – we talk about this all the time and for good reason – it really works! 

Think about the roots of any plant.  If roots have to grow in a hard, concrete-like soil, the roots will struggle to grow. If that plant is a carrot – and we eat the root – then we will have small carrots.  If that plant is an ornamental flower and we have small roots – then the flower or foliage of the plant will tend to be stunted too.

So – to make the roots happy – we like to have a nice ‘loose’ soil versus a rock hard soil.  The best way to loosen up soil is to add organic mater.

A quick lesson on soil.  Most soils are made up of many small particles of stuff. Most of the stuff is mineral in nature, some is organic and most of the soil particles are pretty small.  The smaller the stuff – the more ‘heavy’ a soil will be.  Heavy clay based soils are made up of mostly small and flat particles that pack together so tightly you get hard soil difficult to even get a shovel into.  As soil particles get bigger – we move up to more ‘loam’ type soils – that are generally happier from a garden perspective.  Really big particle soils get ‘sandy’ which is easy to work but then we have new issue of how do we keep water in the soil.  Most of the soils we see in homes around Ontario are clay’ish in nature.

Ok – so if your soil is ‘heavy’ and probably clay based – what do you do?  Our goal is to make the average soil particle size larger – and to do that we add large amounts of ‘organic’ mater.  Organic mater compared to little, tiny clay particles is really big – with chunky and fibrous bits that fluff up any mineral soil. When organic mater is mixed with small clay particles, the new blended soil will allow air and water to penetrate and give roots a chance to grow down. 

So – adding organic matter to a heavy soil will solve the carrot issue.  Problem now is that we need to add a lot of organic mater – and blend it with the heavy soil.  Typically we take a few seasons to whip a heavy soil into shape.  We like to spread 7-10 cm (3-4 inches) of compost, well-aged manure or peat moss on our heavy beds and then spend time with a good roto-tiller or spade to ‘blend’ the soil, deeply mixing the organic mater into the beds.

Yup – 7-10 cm is a LOT of organic mater – and we agree that it can be a bit of work to spade or even use roto-tiller.  But if you are being serious about growing the worlds best carrot – we usually need to loosen up the soil!

On a really poor heavy soil it may take a few years worth of work before we end up with a rich and loose loam type, but that is part of the adventure of gardening.  We also think this adding of organic mater is a lifetime process.  Once you have your garden soil nice and loose you may cut back on the amount of organic mater you add every year, but you should always add more.

Now – if you have the opposite issue – and have a sandy soil that is easy to work but holds little water – surprise – same solution – add organic mater and roto-till. Here the fibers actually close the gaps and help hold water and nutrients.

So consider the opportunity to add some (or a LOT) of organic mater to your garden beds this spring.  A big pile of compost – a wheelbarrow- maybe some Tylenol after – and your soil will thank you!