Meet Mark Cullen

Canada's best known gardening personality, Mark Cullen believes that Canadians of all ages need to play more - preferably in the dirt. A best-selling author with over 400,000 books in print, Mark reaches over one million Canadians every week through various media outlets. He is Home Hardware's horticultural spokesperson and regularly contributes to various magazines, gardening shows and newsletters. With a familiar style that people can relate to, he delivers a message that is compelling, fun, informative and inspirational - all based on his organic approach to gardening. In his spare time Mark enjoys driving his Ford Model A - and of course he loves to garden.

Get the Most from Your Soil

~ May 11, 2011

Perhaps you have heard me say this before but these are words to live by: 90% of the success that you achieve in your garden is the direct result of proper soil preparation.

So what does that mean to you? ….. glad you asked!

First, figure out what type of soil you have.

The simplest and most accurate way is to figure out your ‘soil type’ is the jar test. Simply take a shovel full of your soil, mix it together and then take one cup of soil from that and half fill a 1L mason jar with the soil. Top up the jar with tap water and shake it for 5 minutes or so. Then let it sit for 24-48hrs while everything settles.

What you should see is three layers or ‘strata’ of soil on the bottom half and somewhat murky water on the top half with floating organic matter. The bottom layer will likely be separated into 3 layers: sand on the botttom, the middle silt and the top clay.

Looking at the jar carefully you can estimate the proportion of each layer according to the soil triangle.Ideal soil is a sandy/medium loam which is approximately 40 percent sand, 40 percent silt and 20 percent clay. This is a great all purpose soil for any garden bed no matter what you want to plant. It allows plants to root easily, holds onto water but also drains excess water easily.

In reality most garden soils do not have this composition and need some amendments.


The easiest way to deal with a primarily clay soil is either to dig it out and remove it to a depth of 40 cm and then fill in the void with good quality triple-mix and as weed free as possible. Triple-mix is an equal mix of peat, compost and sand. Add about 10 cm more triple mix than soil that you removed. The new soil should be well above grade for it to provide a good home for your new garden. It will settle over time and you will add more each year to keep it topped up.

If you do not want to dig, remove and backfill with the ‘good stuff’ (and if you have a lot of patience!) add sharp (coarse) sand and well rotted compost which will help loosen up the soil, improve drainage, air circulation and organic nutrients. Turn it into the existing soil the best that you can using a shovel, spade or rototiller.


Dealing with a primarily sandy soil is much easier; to do this till in peat moss and well rotted compost or manure which will improve the soils ability to hold water but will also add missing nutrients.

Next week: knowing the acidity (or pH) of your soil – why it is important, how to do it and what to do with the information.