Shop Products
Houzz Logo Print
lynn_nevins

general Q on dormancy/winterizing

Lynn Nevins
20 years ago

I have posted a number of times in different forums, and I've also scoured my bookstore, and have yet to find a source of information that can explain the whole concept of dormancy, how to care for container plants kept out in the winter, what to expect come Spring, etc.

Today for e.g. I went to a website online to order some shrubs. I saw a few nice ones that mentioned how the particular shrubs change color with each season, which is naturally a very appealing thing. The implication was that the shrubs turn a new, interesting color in the Winter, i.e., that the plant is still "alive" and has leaves.

Yet when I called their customer service line to ask a question about the shrubs, the person said that they keep the shrubs in coolers, to keep them dormant, and that that aids the plant for when it is shipped to you and subsequently repotted. In other words, they keep the plant dormant so as to not "shock" it when you put it outside for the winter. He said come Spring, the plant will then "come back".

So by his saiyng the plant was already in "dormancy", that implies that each winter, the plant sort of "dies", right? Can a plant be dormant, or take on the appearance of being "dead", and yet still have colored leaves remainign on the plant?

Does anyone know of a good source or book so I can understand the whole process of dormancy, and how to care for a plant in the winter? Like what about watering a plant in the winter? If the plant is covered with snow, and the dirt is frozen, how can it take in any water? So long as my container plants are OK for my zone (which they ARE), and so long as they are in big enough pots with sufficient potting soil around the roots, with the pots covered in burlap/bubble wrap, can't they all continue to "live", or willl they all necessarily "die" in the winter, and then automatically come back in Spring?

Thank you for reading!

Comments (5)

  • Lynn Nevins
    Original Author
    20 years ago

    Another question just came to mind.... so many questions!.... I really dont' understand this whole dormancy/winter thing...

    Let's say I buy a new plant that is appropriate for my zone. Now that it's getting colder out, with night-time temps sometimes in the low 40s', should I NOT put the new plant out this first year for some reason, or should it be just as OK as my other container plants that are already outside, so long as I repot it with extra potting soil, and wrap it in burlap, etc.?

    Or since it may be a new plant straight from a nursery, is it better to first keep it INDOORS for this winter, and then once I can put it out come Spring, it should then be OK from there on it, even in the Winter?

    TX!!!

  • Lynn Nevins
    Original Author
    20 years ago

    I guess I should think of my potted plants that I'll keep outside in the winter almost the same way I think of plants/trees that are in the ground. I mean, I realize that the ground is able to keep the plant roots warmer than a pot would. I know all the steps I need to take to keep my potted plants warmer. But I was concerned over what would happen to the plant itself, or to the part above the dirt. I didn't know what I should expect. But I guess whatever happens to plants in the ground will generally be the same for potted plants. So if a certain perennial plant dries up and looks "dead" in the ground, the same will happen to the potted plant, and it should come back in the Spring, just like the plant would if it were in the ground. (That is, provided I did a good enough job of keeping the roots warm in the pot!)

    I was also concerned about if I should still water my outdoor containers in the winter, to help to keep them "alive". But again, I guess it would be no different than plants that are outside in the GROUND, right? Nobody waters their shrubs or trees or winter plants in the winter right? I mean, it's sort of impossible isn't it with such cold temps, and with the dirt being all hard? So I guess the same would apply to my potted plants then? But what about those plants that truly do continue to thrive through the winter, like evergreens or certain shrubs. How do they continue to thrive without water in the winter?

    TKS!!

  • Saypoint zone 6 CT
    20 years ago

    hi yippee,
    I've not done any container gardening except for houseplants and summer containers on the patio, but might be able to answer some of your questions. I'm not an expert, so anyone who has better information than I do is invited to correct me.

    Plants that go dormant aren't dead, they just stop growing above ground. The roots can continue to grow until the soil freezes solid. Plants need water even in winter, and pots dry out much faster and more completely than garden soil would, so you should water the plants if they are dry when not frozen. Gardeners do water their plants in winter, but usually only recently planted ones. Well established older plants have a large enough root system to survive in the ground. Evergreens need water as much as any other plant. Check the requirements of the individual plants, as some like more moisture than others, and some will rot if too wet in winter.
    Any plant that is 'not appropriate for you zone' will likely be killed dead if left out all winter. You should bring these plants inside, a garage or cool porch would be ideal unless they are tropical plants, in which case indoors is best.
    Plants that are hardy for your zone (AND good candidates for container growing) don't need to have their pots kept 'warm'. Insulating mulch is used on garden plants after the ground has frozen to keep it frozen. Freezing and thawing can heave the plants up, disturbing root systems and exposing them to winter damage. I would think that more damage would be done by drying out than by cold temperatures.
    And finally, plants that are advertised as having 'winter interest' may be deciduous or evergreen. Obviously, the evergreens keep their color, and some turn slightly in winter, add some interest. Plants whose leaves die in winter may drop them, but some plants keep their leaves, brown or otherwise, and can add texture. Some have beautiful branch colors or bark textures, or shapes. Red twigged dogwood and Harry Lauder's Walking Stick come to mind.

    Here is a link that might be useful: winter plants

  • Lynn Nevins
    Original Author
    20 years ago

    Some very helpful info in there, esp. on the plants heaving up due to temperature fluctuations. And I loved the Red Twigged Dogwood. Gosh, I may just have to get one for myself!

    Another question if anyone can answer it....

    Let's say I have a plant (like a fern for e.g.) that can survive the winter in my zone, so long as it's in a big enough plastic pot, and so long as I wrap the pot in burlap. I could also take this same plant indoors, and it would also do just fine. Are there any pros/cons to winterizing versus overwintering? In other words, are there some plants that are better off dying down in the winter? Will they potentially come back bigger and better in the Spring? I know there are some plants that actually NEED to go through the different seasons out of doors, in order to trigger certain things in the plant, rihgt? Tx.

  • gardengal48 (PNW Z8/9)
    20 years ago

    Plants native to the temperate zones of the world generally do need to go through a chill or dormancy period, even those with evergreen foliage. Envision that plant in its natural landscape - would it experience low winter temps, snowcover, is it herbaceous? If the answer is yes, then a period of dormancy and/or winter chill is in order. Encouraging plants (temperate in origin, not tropical) to continue growing throughout the winter tends to stress them and put them off their normal cycle. It is done all the time by growers and is called forcing (eg. florist's hydrangeas), but it not recommended unless you have the proper equipment and of course the knowledge of how to accomplish this. And plants grown in this manner need a period of adjustment and hardening off before they can safely be transitioned into the garden - and some never transition well.

    Overwintering hardy plants indoors is tricky. Typically our homes are too warm and too dry. If necessary, an unheated garage or cool greenhouse or basement is much preferable to overwintering inside the home. Temps should probably not exceed 45 degrees and can be allowed to drop to freezing, provided the roots are not allowed to freeze. Freeezing temps should not affect top growth of hardy plants at all - the deciduous or herbaceous plants will lose their foliage and die back as nature intended, the evergreens will remain unchanged, provided things like wind chill, dessication and moisture levels are all properly addressed.

Sponsored
Iris Design Associates
Average rating: 5 out of 5 stars22 Reviews
Northern Virginia Landscape Architect - 13x Best of Houzz Winner!