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esther_b

My head is spinning---how to winterize my hostas in big pots!

esther_b
10 years ago

I've done a forum search, asked various vendors, and have been supplied with elebenty-seven different answers. I probably have only a few days until this weird warm November in Queens finally plunges into a freeze. I have my mini-hostas in the 16" glazed pot and my lovely Georgia Peach heuchie in a 12" glazed pot, in the lee of the Obligatory Bushes.

Should I wrap the pots in bubble wrap and then something opaque to avoid the greenhouse effect? Should I create a wire fencing cage around the pots and fill with wire fencing cage with leaves stuffed in? The 16" pot is way too heavy to move. I don't have an unheated garage. My storage unit is probably heated to some extent. I don't have a porch to stuff them under.

Please help to unconfuse my mind. I want to save my beloved little hostas and my adored George Peach heuchie.

Comments (38)

  • ken_adrian Adrian MI cold Z5
    10 years ago

    you have weeks if not months ...

    you are confusing a freeze involving air temps..

    with a ground freeze ...

    i would have used a pot in pot system.. so i could have protected my beloved glazed pots over a z5 winter here in MI ... by removing all the plants and media.. to avoid freezing media expanding and cracking the pots ...

    i am sure other .. more zone appropriate peeps will come along..

    but be certain.. you have plenty of time...

    ken

  • esther_b
    Original Author
    10 years ago

    Thanks Ken.

    As you pointed out, I am in Zone 7b vs. 5, so that will help somewhat. My previous experience with leaving glazed ceramic pots outside during the winter has been OK, with my strawberry pot having survived 3 winters so far with no problem.

    I will enjoy the time of which you speak, as many of my annuals are still blooming their heads off. I want to experiment this year with the hanging of my geraniums in paper bags in my sort-of-heated storage unit on the first floor of my building, but they are still in full bloom, too.

    Rob Mortko of Hostaguys suggested piling leaves all around my ceramic pots and not using plastic bubble wrap. NH Hosta said the bubble wrap would be fine. Other people are putting the pots in garages, which I previously stated was not an option here. Can you see why I'm confused?

  • bkay2000
    10 years ago

    I don't understand why you would want to pile leaves on or wrap the pots in bubble wrap. I wouldn't think you are trying to keep them from getting too cold. Generally speaking, you are trying to keep them from sitting in water during any freeze/thaw cycle.

    Your zone is not that different from mine, which is 8a. I've never done anything to mine over the winter. They just sit there. It's always worked out fine until this year. We had a warm January followed by a cold February. It just kept going up and down all spring, which stalled out several hosta. I had some rot. I don't see how leaves or bubble wrap would have changed that situation.

    I guess I'm not sure what you are trying to accomplish. Are you trying to keep the hosta cold, warm or dry? Or are you trying to save the pot?

    bk

  • esther_b
    Original Author
    10 years ago

    Bkay,

    The leaves idea was told to me by Rob Mortko of Hostaguys. He suggested it in order to save my hostas and heuchies from excessive freeze/thaw. He told me not to use bubble wrap.

    NH Hostas told me to use bubble wrap.

    This is the source of my confusion.

  • almosthooked zone5
    10 years ago

    I may be wrong but my understanding was to tip the pot on the side and wait for spring ..period. I only have four in pots and so far never lost any but then it is a different weather here in the winters

  • old_dirt 6a
    10 years ago

    I am new to hostas in containers other than a few I was to lazy to get in the ground in years past. These few seemed to fair well without any special attention.

    This year I have about 10 in a variety of pots. I have a couple minis in original nursery pots, a few in terra cotta pots and a few medium and large ones in ornamental plastic. I already have a small fenced in bed for annual cut flowers and using it for the pots this winter. I did tilt them all on their side to control moisture and have covered the entire area with about 2 feet of leaves.

    I think the leaves will help to maintain the temperature of the soil in the pots. Once they are frozen, I think they will not thaw until I uncover them in the spring. This should prevent any heaving, especially with the minis.

    Maybe I've made to much work of it but I am new to it and will see come spring...

  • mctavish6
    10 years ago

    I am no expert on hostas in pots surviving having lost quite a few that rotted. I have learned a few things from my mistakes and listening to Ken. I think the biggest thing is them getting too wet without proper drainage. The mix needs to be really porus. Tipping them on their sides keeps water from collecting on the top around the crown after the soil itself has frozen (not letting the drainage happen).

    Putting them on the north side of the house or a fence keeps direct sun from hitting them in early spring and starting them growing when there is still a chance of a late freeze. I would never wrap or cover the plants with anything. I've had hostas tip out of the pot and all the dirt wash off over the winter. In the spring I find these little orphens with roots hanging out in the air and they have always been just fine. It's when they have wet soil or water standing on the top that they are in trouble.

    I can't speak to the survival of the ceramic pots themselves because if water were to freeze in them I assume they would crack. I know my sister grows over 300 plants (most in pots) lots in ceramic. She is in Seattle area in zone 8 I think. Not very far off from your condidtions but there could be a difference in freeze thaw cycles which she never seems to have.

    The heucheras will survive just fine without you doing anything. They will gradually climb up out of the soil and will have to be planted deeper but that's ok.

    Good Luck

  • bkay2000
    10 years ago

    Are you sure you are in 7b? That's the zone of East Texas. No matter what you do, they are going to freeze and thaw in that zone. It's 20 overnight and 45 in the day and 60 a couple of days later.

    Consider the idea of keeping them dry rather than trying to prevent freeze and thaw.

    bk

  • esther_b
    Original Author
    10 years ago

    Bkay:

  • don_in_colorado
    10 years ago

    Lost writings of William Shakespeare..ahem...

    "7B or not 7B, That was the question; verily, this USDA Zone is for Lady Esther's realm of Queens, New York...ALAS, poor 'Great Expectations', I knew you not well..."

    This post was edited by Don_in_Colorado on Tue, Nov 12, 13 at 3:18

  • esther_b
    Original Author
    10 years ago

    For Don B in CO:

    Texas is a real big state, it even sports a star
    And New York is a smaller state and ever so darn far
    But the two actually get together
    If in nothing but their weather!
    Zone 7b, that's me,
    And part of Texas I see.

  • Jon 6a SE MA
    10 years ago

    The idea behind using mulch in the winter would be to prevent freeze thaw cycling, not to keep them from freezing or thawing. In colder areas it would keep the ground frozen; in warmer climates it would keep it from freezing; in each case it would eliminate or lessen cycling.

    I had someone in a store explain to me that pots intended for outdoor use year round are double glazed (twice into the oven and out). I don't know how anyone could tell which type they have unless they were labeled when purchased. 'Outdoor' pots would definitely have a price premium.

    Jon

  • bkay2000
    10 years ago

    I still don't think you can lessen the freeze/thaw cycle in zone 7b enough to make a difference. Theres's no way to keep the pots frozen even if you bury them under a ton of leaves. I also don't think the freeze/thaw is the problem. It is the wet that causes the rot, not the freeze/thaw cyle. In colder areas, the pots never totally thaw out and hold water in the top if not tipped. The pots thaw completely in the warmer areas.

    I've had hosta in pots in zone 8a for 15 or 20 years. They freeze and thaw all winter. This year was the first year I've had a real problem. I think everyone had a bad spring this year. Some of my problem was caused by me watering too soon. Then, it got cold again and I had stalled out hosta in cold wet pots.

    I do, generally, have some cold damage. It's not significant. It is usually limited to the fragrants as they come up the earliest. They would not come up that early were they in the ground, but they are not. That's the price you pay for for growing in pots.

    I think Esther is getting advice from people in a lot colder area than where she lives. It sounds a little nutty to cover your hosta in cold wet leaves to me.

    bk

  • hostafreak
    10 years ago

    I really don't grow hostas in pots,let alone ceramic pots. I do have several chimney flues,and two half whiskey barrels with hostas in them. Those,I just leave outside year after year,and let them get covered with leaves. I used to leave outside my gnomes,which I made years ago in Florida,but I have lost two of the five to freezes,so now I bring them in every winter;in fact they are already in my garage. That's my take on the subject. Phil,zone 6.

  • esther_b
    Original Author
    10 years ago

    Hostafreak,

    It would be great to have my 16" and 12" pots covered with leaves, but the "landscape workers" Mow & Blow blow all the leaves away with their obnoxious loud and smelly blowers. Others in this thread have counseled me not to cover the pots with plastic or anything. If I tip the pots on their sides, what is to prevent all the soil, gravel topping, and mulch from just spilling out onto the ground?

  • bkay2000
    10 years ago

    It will spill out. That's the problem. People saying to tip your pots live in areas where their's will stay frozen all winter. Your's won't. Pluis you have some small plants in big pots. They will thaw and freeze repeatedly.

    I really think you'll be fine if you do nothing. I agree with Phil. I never do anything to mine and they are always fine. I had some damage this year, but it was a really unusual spring. The only thing I would watch for is keeping them from getting/staying too wet in the spring when they first come up. It's never been a problem for me until this year. I don't expect it to be a problem again, but will still watch for it. You can always add pot feet or some kind of riser to make sure the pots drain well.

    Good luck on your decision, but I don't think tipping will help you.

    bk

  • esther_b
    Original Author
    10 years ago

    Bkay,

    I'm glad that you see the logistics about the spilling out of the pot contents. My main concern is that the plants in the pots have less root insulation than plants in the ground. The mini-hostas in the 16" pot are planted quite close to the edge of the pot, for example. That is why I thought wrapping bubble wrap around and around the pot would give the minis a better chance to make it through winter. And that putting plastic over the top of the pots would keep out the precipitation which would then freeze within the pot and interfere with drainage. I even proposed to Rob Mortko of Made in the Shade putting a plastic bucket over each of the 2 pots, to block snow getting in there to freeze in the first place and offer a little insulation. He said it would be like a greenhouse effect. I thought that would be if the buckets were CLEAR, but I meant to use opaque colored buckets.

    Now what do you think??

  • bkay2000
    10 years ago

    Rob Mortko is in Kansas City. Kansas City spends the winter under 5' of snow and ice. If you're 7b, you don't.

    You'd get better advice for 7b by asking Tony Avent. He's in the Carolinas. Also, there are several people on the forum in 7a and 7b. Ask them what they do.

    I believe you are overthinking this, however.

    bk

  • Steve Massachusetts
    10 years ago

    Esther,

    I wait until my pots have frozen before I tip them on their sides. That way the potting mix stays put. For me that happens in December. I don't know if that applies to you or not. You might be able to keep your pots upright all winter, I don't know. If it were me I'd tip them on their sides.

    As far as ceramic or clay pots in your area. They might survive your winter and they might not. I've left some glazed pots outside in my 5B winter and had them survive. But I won't do that with expensive pots. It's too risky. I know some people who line the inside of their glazed pots with bubble wrap, to absorb the expansion and contraction of the mix, and that works for them. But you can't do that now.

    It's probably less of a risk for you to leave out glazed pots, but you may end up having to replace them. The plants should be fine.

    Steve

  • esther_b
    Original Author
    10 years ago

    Steve,

    Thanks for your input. My glazed strawberry pot outside has remained ok during 3 winters now. So, to tip/wrap/cover?? The question still not settled...

  • Steve Massachusetts
    10 years ago

    Either tipping or covering should do the trick to keep it dry during dormancy. Wrapping with bubble wrap won't help. In dormancy you want to get the plant dormant and keep it that way until you are past the last Spring frost. This is why you want to keep it in the shade. If it freezes that's OK. They will survive to zone 3 so don't worry about freezing. Just keep it dry and shaded.

    Steve

  • esther_b
    Original Author
    10 years ago

    So, STEVE,

    How about putting plastic buckets/tubs on top of the pots? That would keep them dry and shaded. I don't know why Rob Mortko of Made in the Shade said that would cause a greenhouse effect. I suppose if the bucket/tub were a very dark color, that could occur. I could always wrap it in aluminum foil to deflect the sun.

    Meanwhile, the associated heuchies survived the other night at 30 degrees and look just about as good as during the summer. Is that crazy, or what?

  • Steve Massachusetts
    10 years ago

    That's interesting, Esther. I hadn't thought of that one. Since they would be dry you wouldn't get crown rot. Here's what I think Rob was talking about. If you put a 5 gallon bucket over a plant and it was in the sun, you would warm up the air around the plant and the bucket would tend to insulate the plant. What might happen in that situation is that the plant would emerge from dormancy before it would if it were in the ground. Just as if you overwintered in a garage. So you could do that, but you'd have to check the plants in early Spring. If they begin to grow early you could uncover them during the day (when it's above freezing) and cover them up again at night.

    My Heucheras are still looking pretty good too. They must have a lot of sugar water in those cells.

    Steve

  • beverlymnz4
    10 years ago

    Another thought, an opaque but light colored tub with ventilation over them to provide shade and dryness. The light color to reflect light.

    Still, north side of a building is better, it will warm up under that bucket no matter what if its in the winter sun. I take it you don't have that option and that's why your considering different options.

    Happy hostaing,
    Beverly

  • esther_b
    Original Author
    10 years ago

    BeverlyMN,

    No, you are correct--I do not have the option of putting the pots on the north side of my building. That's public ground, no gardens there. My 2 concerns with putting a tub or bucket over the pots is (1) condensation could cause it to be too humid under the tub/bucket, giving rise to fungus/mold and (2) the overheating under the bucket.

    I have 2 small umbrellas I don't use, but I think snow piled up on top of them would break the ribs. Also, there are plants right in the middle of the pots, where to stick in the handles would be a problem.

    What about plastic garbage can lids mounted on sturdy dowel rods? Or mounting the tub/bucket on very short wooden posts to allow air to circulate up under the tub/bucket?

  • Steve Massachusetts
    10 years ago

    Esther,

    If you don't have a shady spot to keep the pots, then cover them with chunky mulch like wood chips or pine nuggets. Something that will keep the plants shaded but will allow for air circulation. Another type of mulch to use is branches from an evergreen. If someone is tossing out an old Christmas tree after the holiday then cut up the branches and put them over your tipped over pots. By December 25th the pots should be good and frozen.

    Steve

  • bragu_DSM 5
    10 years ago

    Don't over think this.

    Most of the plants can be easily replaced.

    Digging a pot size hole in the ground and sinking the pot usually works for me ... but this is not NY.

    Winter is a time to make lists ... not fret over what you have out.

    But then again, it depends upon what your definition of is is ...

    dave

  • esther_b
    Original Author
    10 years ago

    Dave (bragu) & Steve,

    One of the pots is enormous--19" wide x 15" tall. No way would I be able to bury that pot. It would also be very difficult to bury the 12" x 9" high pot, as the soil beneath the topsoil I placed in the garden is contractors' fill clay garbage, full of rocks and such, not diggable.

    There aren't that many Xmas trees discarded in this area, as it is very heavily populated by religious Jews. The few Xmas trees discarded are promptly picked up by the garbagemen, who then feed them into chippers to make mulch for city parks.

    I would have to have some sort of restraining fencing around the pots to keep the mulch you suggest I pour over the pots from just scattering.

  • ci_lantro
    10 years ago

    After they've gone dormant, I think I would lay a couple of pieces of 1'' x 2'' or 2'' x 2'' lumber across the top of the pot & put a piece of rigid foam insulation board over the boards and weight it down with a brick. By elevating the insulation over the pot, air can still circulate and the foam board will keep them dry and provide some insulation to minimize the freeze/ thaw cycles.

    You might need to shield the pot sides from sun exposure, too. Maybe make an open ended 'box' (sleeve) from in insulation board to slip over & surround the pot...just be sure to make the box short enough so as not to impede air circulation to the surface soil.

  • ci_lantro
    10 years ago

    Heck, now that I think about it, you could prolly re-purpose some of those Omaha Steak styro-coolers...just cut the bottom out of it & use boards to keep the lid elevated up off the top of the cooler. If you like, you can paint the polystyrene with an acrylic (craft store) paint to help it kinda' disappear...although white works up here in the snowbelt!

  • esther_b
    Original Author
    10 years ago

    Cilantro,

    I was thinking of maybe sliding the pot upright sideways into a plastic garbage can or large bucket. I could get styrofoam boxes at the local pet shop, they use them to ship tropical fish. However, various people on the forum have told me it would not be good to insulate, that the plants can survive the winter here. It's the freeze-thaw-freeze-thaw that is harmful.

    What do you think about the sideways shove into an open bucket or garbage can?

  • zkathy z7a NC
    10 years ago

    Hi Esther,
    I think ci_ lantro is on to something here. You could have some wooden tops made individually for each pot that had an overlap to prevent rain intrusion, a couple of furring strips to insure ventilation, some pegs to keep the tops in place, then stick pots with tops behind the Obligatory Bushes for shade. You could have someone build them for you and even paint them so they would last for years. Good luck!
    Kathy

  • esther_b
    Original Author
    10 years ago

    ZKathy,

    I've been looking into plastic buckets and garbage cans for a few days now, vs. having to build a wooden top and then paint/polyurethane it. There is a 17 gallon party tub available at various places around town. Placing 4 wooden dowels or 4 green vinyl-clad plant supports equidistant into the soil of the pot would support the bottom of the tub a couple inches above the soil line of the pot and allow it to have some ventilation. There would be about an inch or two of airspace between the wall of the tub and the rim of the pot at the top.

  • zkathy z7a NC
    10 years ago

    Looks like you're close to a solution. If you get a good price on party tubs, buy some extras. They're not UV stablized very well. Send us some pics when you get it done!
    Kathy

  • ci_lantro
    10 years ago

    As to the garbage can idea---if you have it exposed to the sun at all, it's going to heat up. (Think how a car sitting the sun will heat up in the winter.) You don't want that.

    I'm familiar with zone 6 weather, having lived & gardened there for many years, so I have some idea of what you're dealing with...that is, you need to keep the soil cold when you get those weather warm-ups in mid-winter. i.e., the idea behind the insulation is to keep the heat out and the cold in the pots, to moderate the inevitable wide swings in temperature. (Think 'ice chest'.) If the pots are not in the sun, then the insulation board on top of the pots is prolly going to be sufficient. If the pots get any am't of sun OR are close to a bldg., then you need to think about keep the whole shebang cold. Naturally, you would place the insulation barrier around the pots after it's turned cold, really cold.

    About the wood tops idea...an inch of wood has an R-value of less than 1.5...compared to R-5 for an inch of XPS (the pink stuff) and R-8 for ISO (the foil faced yellow stuff). So, although wood is an insulator, there are better choices. Of course, you could glue XPS to the wood if you want to.

    Oh yeh, the pink stuff, XPS, will hold up to the elements much better than the foil faced ISO--it's yellow underneath the foil and is much more brittle than XPS. Also, the R-value of ISO degrades to where it's only marginally better than XPS.

  • esther_b
    Original Author
    10 years ago

    I am zeroing in on a 17 gallon Rubbermaid Brute white rectangular tote. If I can manage to shove the 19" diameter pot into the tote while the tote is laying on its side, with the open end facing the Obligatory Bushes, there will be ample ventilation, but it will be difficult for moisture to get it to freeze, right? And how about a smaller white tote (to reflect sunlight so it doesn't get too hot) for the 12" pot with the heuchie?

  • ci_lantro
    10 years ago

    That oughtta work....

    ....until someone passing through decides they need that nice tote.

  • esther_b
    Original Author
    10 years ago

    Cilantro---

    If some lowlife passerby decides they need that nice tote, they will have to snap the airplane cable I will loop through the handle and around the Obligatory bushes. Also, without the lid, its value is much less.