zooba72

Can any perennials survive in a Planter through a Zone 7 Winter?

zooba72
12 days ago

Hello Everyone - I'm wondering whether anyone has had success using perennials in concrete planters ? I have a bunch of concrete and porcelain planters but would like to investigate using a perennial as opposed to an annual. Is there anything hardy enough to survive the Long Island winters ? Appreciate all suggestions / opinions. Thank you !

Comments (11)

  • laceyvail 6A, WV
    12 days ago

    Sure. Many survive a zone 5 winter. The rule of thumb is that the plant should be hardy to at least one zone colder than where you are--better still, 2 zones colder. Also, if the planter is large enough, you could line it with heavy duty bubble wrap before you even add soil and plants.

  • ken_adrian Adrian MI cold Z5
    12 days ago

    you dont know what winter is.. in z7 ... lol ..


    winter protection is not really about the plant .. though that is a good place to start ...


    but more importantly .. the most important thing.. in a pot.. is the media ...


    and in fall that media has to allow the pot to properly drain.. so when the plants are going into dormancy ... they are not in a lot of water ...


    and you have to maintain proper media drainage thru the whole winter ...


    e..g. in my z5 MI .. i would not want a planter to freeze solid.. full of water.. because roots need air as much as water.. and being frozen in a giant ice cube is not free air movement ...


    i presume.. in your version of winter... you would not want to accumulate rain .. ???...


    so you need planters with high drainage... with a media that encourages such ...


    and if you accomplish that ... i suspect that winter temps ... are not really going to be an issue ... though it sure wouldnt hurt to have one zone colder plants... just in case ...


    anyway.. back to the premise... plant selection is just about the last variable there is.. imo ...


    ken


    ps: there is a container forum .... though i dont know how active it is ....

  • harold100
    12 days ago

    In zone 7 Va I have a tall sedum in a 20 inch thick plastic pot and it has survived about 5 winters. Temps are usually 35 to 45 but we did get 2 nights at 28 this winter.


  • dbarron
    12 days ago

    Another issue with winter perennials in containers are that they do need to be watered...but with the caveat Ken mentioned of not drowning them. It's far more of a balancing act, imo.

  • gardengal48 (PNW Z8/9)
    12 days ago

    Despite other's thoughts to the contrary, it DOES depend on the plant. In a container, plants are often exposed to ambient air temperatures that are far colder than they would experience if in the ground. And the roots are the most cold sensitive portion of the plant. That is not so obvious when planted in the ground as all that soil mass acts as an insulator. In a container you are lacking that insulating soil mass and plant roots can be much more easily damaged. As an example, Japanese maples are hardy for inground plantings to at least zone 6, often zone 5, so the potential of a -5F to -15F winter cold. But JM roots can be damaged at temperatures less than 25F, which is easily encountered in a zone 7 winter.

    The sedum above is ground hardy to zone 3.....a zone 7 winter would be a snap for it :-) The caution for selecting plants a least 2 zones hardier than yours is valid.

    And the concerns for a fast draining medium are no more pressing for winter than they are for any other time of the year. That should always be a primary concern for any container growing.

  • diggerdee zone 6 CT
    12 days ago

    zooba are you planning on leaving the planters where they are for the winter? Or can you move them? I think either way it can be done, but if you can move them (into an unheated garage or shed, or even against a wall with piles of leaves around them, etc) that affords a bit more protection.

    I used to have a pot ghetto of up to 240 pots, of ALL sizes. Some were large decorative planters, some were new plants in 2-inch pots that I hadn't gotten around to planting yet. For years I would drag them into the garage and drag them out again and had minimal losses. Despite the fact that the ghetto eventually got smaller, I seemed to get lazier, and the pots didn't all make it in the garage every year. Often just on the driveway without any protection. But for the most part they still did fine. Perhaps a few more losses, but those were the smaller pots and smaller, less-established plants.

    I used to put tulips in pots because I treat them as annuals, planted in fall. One year there was a pot of them right outside the garage door. In mid-winter, I finally decided to drag it in the garage, and lifted it, and it cracked in half, but remained frozen to the ground. I could see some of the bulbs. Welp, there goes those tulips, I thought. But they were fine and bloomed beautifully in spring.

    So it can be done. I agree with going down a zone if you are planning on keeping them outside. However I also agree with drainage. I once planted about half a dozen pots specifically for winter interest, out on the patio, all a zone hardier. They all looked great in the winter, and then I lost three of them in spring due to drainage issues.

    So I would look around for plants you like that are hardy to zone 6, maybe zone 5 if you want to leave them for winter interest, and do make sure they have proper drainage.

    Good luck!
    :)
    Dee

  • felisar (z5)
    12 days ago

    Like diggerdee I routinely overwinter (Z5) many pots (300 to 500) of various sizes every winter. My outside holding area has a straw bale perimeter and the pots are placed side by side. The area is protected from the northwest wind and is not in a frost pocket. My survival rate is usually 90%. I agree with Ken that in addition to a protected area, free draining soil and a container with lots of drainage holes is the key to survival. Another important element is pot size, the bigger the pot, the better the chance of survival. I would also suggest the best decorative containers for maximizing survival are the large, double walled fiberglass pots. They are expensive but worth every penny.

  • cyn427 (z. 7, N. VA)
    11 days ago
    last modified: 11 days ago

    I am in zone 7 in northern Virginia. I have overwintered pots with perennials many times. I usually move most of the clay/ceramic pots into the unheated garage. I have left the other pots outside and some of the really large, heavy pots stay outside too. Everything seems to come through just fine and we usually have several nights/days when our temps go down into the teens and the last two years, we have gone down to 0 degrees!

  • zooba72
    Original Author
    11 days ago

    Wow! I really appreciate everyone's comments and suggestions. I'm optimistic that I'll be able to make this work. I currently have about 12 concrete planters that I'm looking to populate. They're not huge, maybe the equivalent of a 3 gallon container. I'm going to evaluate the drainage, but might be able to drill additional holes using a masonry bit. Our winters here can get pretty cold and I would prefer not having to haul those planters anywhere as they're pretty heavy when filled with soil. In reviewing my options, I recently read that Bearded Iris are capable of surviving in Zone 3. I have tons of these that are in need of separation, so I think my plan is to use my excess Iris as a test. Hosta was another option, but we've been overrun by deer, and the Iris fare much better than Hosta. Again, I appreciate everyone's help.

  • diggerdee zone 6 CT
    11 days ago

    zooba with those heavy planters you could plant your plants in a different pot a tad smaller, and then drop that in the concrete. It might be a bit difficult to get out but you can put a strip of fabric etc. in first to facilitate lifting in the falling. If it's something that's dormant anyway then it won't matter if you take it out for winter to overwinter elsewhere. I've seen people put winter arrangements in their heavy planters - branches of evergreens, berries, etc - to have something there for winter while their annuals or perennials are gone.

    :)
    Dee

  • ken_adrian Adrian MI cold Z5
    11 days ago

    They're not huge, maybe the equivalent of a 3 gallon container. I'm going to evaluate the drainage, but might be able to drill additional holes using a masonry bit.


    ==>>>


    agree with digger ... use a pot in pot system ... where you hide a common nursery pot.. in your decorative cement pot ...


    and then in winter.. take the plastic pots out.. and store them separately ...


    and dont think adding a layer of rock in the bottom accomplishes anything.. that is an old wives tale ... or maybe crazy old man... i dont know.. lol ...


    do nurseries still have recycle bins??? .. thats where you might find the pots you need ... july and august is a great time to do this.. and then.. in fall. repot your stuff ...


    i was told.. cement never stops hardening .. and if these are old cement pots .... you might drill thru it ... but im not sure it would work without some serious drill motors and drill bits .. and by the time you buy those ... other ideas may have seemed better ... lol ... unless you are one of those peeps who also collect tools.. and are always looking for reasons to use them .. lol


    btw: the pot in pot.. also allows you to have duplicates.. so you can switch plants out of your pots during the season ... to either change the show ... or if something isnt performing ...




    ken



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