Marianne's Response

How to Maintain Soil in Containers Over the Winter?

Hi. I have several large planters on my deck in zone 5. Some have just potting soil (no plants), and some contain perennials and some have lilac, forsythia, red twig dogwood shrubs. Question – how to best to maintain the soil and plants over the winter. Is a slow release fertilizer helpful, or would it cause the plants to start growing when they should be dormant. What about a soil drench (neem oil, Castile soap, water) for those planters that had fungus / flea beetle problems over the summer?
Thanks for your help! Susan

Posted by Susan Volk on September 25, 2021

Marianne's Response

In the winter your plants will go dormant so no need to fertilize or attempt pest control. Wait until you see signs of new growth in the spring and then add the Osmocote slow release plant food to the soil. The fertilizer will release as the soil warms and the plants need it. I am not familiar enough with  soil drench to recommend it. Your insect and disease problems may disappear over the winter as well so wait until you see signs of problems before you treat in the spring. Keep Growing, Marianne Binetti

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