Gardening Question From Crystal:

I am going to be doing some container gardening this summer for the first time. I am trying to do it as organically as possible. I have bough an organic potting soil but would like to add some compost. I have limited space, hence the container gardening, so I have reached out to some local farms looking to buy compost since I don’t have the space to do my own. I have had one person contact me back saying he has composted soil, is this okay to add since I am assuming it is compost mixed with soil that this farmer uses for his ground garden. My concern is the soil part since I have read many times to use potting soil and not garden soil for container gardening.

Answer From Pat:

The words “composted topsoil” don’t make sense, since no one can compost soil. Why don’t you ask the person or company that is selling that product what he means by that terminology. “Soil” is the scientific name for the top layer of the planet Earth and it consists of ground up rock, air, water and organic matter. Compost is made by piling up organic matter in layers of carbonaceous and nitrogenous (green) matter and keeping it damp until it rots. Too many products called “compost” today are little more than ground up wood. This is not compost.

The best answer to your question is below:

If you are filling an 8’X4’ raised bed you can fill it with your own garden soil (earth from the ground) and then amend it with manure or compost twice a year before planting for each season. If you are filling tubs and pots, then be sure before filling the container that you cover the drainage hole in the bottom of the container with a piece of broken pottery and then fill the container with potting soil. The piece of broken clay pot is placed there to keep the soil in the pot but let the water drain out. In other words it provides drainage. Every nursery sells bagged potting soil. It clearly states on the bag that it is potting soil. This is a misnomer in a way since it is not soil, but it is a product that drains well and is made for filling containers in order to grow plants in them.

Never use garden soil (earth) to fill containers. The only exception to this rule is if you live in a place like Claremont California at the foot of Mount Baldy, inland from Pasadena. Claremont has incredible decomposed granite soil that that is mineral rich and drains so well that it can be used for filling pots.

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