What to do with my container garden in winter?
I'm renting (in zone 7, Alexandria VA), so I've placed a lot of perennials in pots. What do I do with them this winter? I've heard a lot of things- bury them, wrap them, mulch, don't water once the ground is frozen, place in a sheltered unheated area- but I guess my concern is with light. How much light should the container plants receive in winter?
I've read that an outdoor container plant should be hardy to a zone - 2 zones from where you live. But I've also read about the freeze/thaw cycles that container plants can go through. Even if a plant is fine with the colder temperatures it will experience in a pot, won't constant freezing and then thawing from the sun still rot the roots? Does this mean that the plant needs to be kept completely out of the sun until spring?
These are great questions and certainly will be a great help to our readers.
First, I'll say this: You can't just leave the perennial container outside for the winter. 99% of the time, they won't make it. The roots don't have enough protection from the freezing like they would if they were planted in the ground.
However, if you have a spot to plant them, Plant! Take them out of their pots, and plant them to the same depth as they were in their containers. Water once or so a week until the ground freezes. Then, don't water again until Spring
when you dig them up and return them to their pots....I guess if you go 3 or 4 weeks without snow or rain, you could water them some.
Your next option is like you stated above, bury them in their pots. It's a great idea...as long as you have space to do so. The same watering as above applies here. The neat thing about doing it this way, is in the Spring, you dig them up and they are literally ready to go. No transplanting, etc.
I'll insert this...no matter what you do, you can't leave terra cotta, etc. pots outside. They crack to easily with the freezing and thawing. You'll need to bury them in plastic pots.
Next thing you could do, again as you mentioned above, is to keep them in a garage, etc. It would need to be around 40 degrees or so. They'll be dormant, so light won't be an issue. What ever light is in the room or not in the room, will be just fine. Water them the day you put them in the garage, and don't water again until you bring them outside for Spring.
As far as light requirements outside, don't be concerned about how much they get. If you plant them or bury them in their pots, their light requirements will then be the same as any other perennial you would have planted in the ground in your garden.
Please let me know if I answered your question well enough or not!