Choosing the Right Soil for Containers

Excerpted from The New Canadian Garden, 2016, Mark Cullen. All rights reserved. Published by Dundurn Press.

The right soil for containers and raised beds is engineered for this purpose.  Garden soil or triple mix doesn’t work well at all as it is heavy and dense.  Weed seeds and diseases are harbouring in the soil and waiting for the opportune moment to strike.  The soil will not drain properly and may become compacted. The result is an unhappy root system and a sad-looking, unproductive plant.

Opt for a good-quality potting soil or vegetable mix that is suitable for using in pots.  These mixes provide adequate moisture-holding properties but also allow for proper drainage. The number one reason for problems with container grown plants is overwatering. Vegetables don’t like to keep their feet wet and too much moisture impedes root growth as it pushes oxygen out and away.

A good-quality bagged soil has some weight to it.  Lightweight products contain a high concentration of peat, which provides little to no nutritional value. However, when peat is mixed, in the proper ratio, with compost, clay, and humus, the result is a well-draining soil that won’t compact easily and will provide exceptional nutrition for most vegetable plants.  If I’m growing tomatoes in a container, I put extra compost in my Mark’s Choice container mix, which adds much-needed natural nutrition and microbes. A heavy-feeder, like a tomato, will benefit greatly from this addition.

Read more in my new book ‘The New Canadian Garden’ available at independent book stores and Home Hardware.