Out with the dead, in with the live...do I need to add new soil?

Question

I've had two very large container shrubs on my patio since spring. One of them recently withered away to nothing, and the other is on its way. (I believe they weren't getting enough sun.) I want to put new plants (more shade-tolerant ones) into those containers, and I'm wondering if I need to empty out all of the old soil after removing the dead plants and their roots.

Can I leave the old soil in the pots and then just add new soil to it when I pot the new plants, or do I need to completely empty the (very large) containers and use all new fresh soil?

Thanks very much!

The reason I'm hesitant to dump the old soil (besides that the containers are so large) is that they have small border plants in them as well, which are doing fine.

Answer 1

Some will say that the nutrients that were in the soil were "used up" and that the only option is to replace all of the soil. Others will say that the soil is somehow filled with disease and should be replaced. We usually will mix the old with some new and fertilize as necessary with a slow release fertilizer and haven't had any problems.

Visit our website for more container gardening ideas at-
http://www.gardening-at-the-crossroads.com/container-gardening.html

Good Luck and Happy Gardening from Cathy and Neal!

Answer 2

I have done that when ones did not survive the winter. After you get out the old plant and its old roots just break up any solid areas so the soil is loose again. While you are down low in that pot throw in a handful of slow release fertilizer of the kind that is recommended for the new plants. Put in the new plants and top off the soil level.

Some people say that you have a risk of getting a fungus infection remaining in the pot and should replace all the old soil with sterilized new soil. I have never done that and have never had a problem like that.

Answer 3

The plants died for a reason that may have had something to do with the soil. If they were diseased, replanting in the same pots may kill your new plants too. Dump the whole works, wash the containers with a bleach solution, allow to dry and start again. Read the label in the plants to see how much sun they can tolerate.

Answer 4

Best to replace the soil and wash out the containers thoroughly before replanting.

Reason is, that plants, as they are dieing off for what ever reason, are less resistant to desease and insect infestation. Lack of proper watering can be a cause of this.

It does not mean your plants are diseased or infested, but why take a chance, to save a few dollars worth of potting soil.