|Hi--I am zone 4-5 and have several potted perennials, all hardy to -20 degrees F. I am specifically concerned about over-wintering my perennial native grasses which are kept on a covered porch. How should I water them during the Fall and Winter?|
|Overwintering containerized plants can be a challenge. Bitter cold, fluctuating temperatures and wind are the main enemies. Using larger containers helps, as does insulating the containers with mulch or other materials packed around them. Make sure the soil is kept evenly moist (but not soggy) up until it freezes. Heavy mulching will also help protect the plants from freeze/thaw cycles which can heave the plants out of the soil.
Some plants may be hardy in your zone when planted in the ground, but not survive in your zone when planted in a container because the soil is more exposed. Note that ceramic and terra cotta pots can crack or shatter when frozen because the soil expands as it freezes, so make sure you are using winterproof containers. Good luck!