What is meant by "winter protection?"

[Joe2758]

I have read over and over in books and online " X bonsai trees need winter protection under X deg F," and such.

Does this mean I need to keep them in a place that will not drop below that ambient temperature, or that they will be ok in those lower temperatures so long as I provide protection via some of the many techniques one can read about?

I am in zone 5/6. I have 2 options for winter:

1. cheap poly greenhouse that stays the same temp as outside, but protects from wind. Here they are exposed to "dangerous temperatures," but at the same time they are "protected."
2. my garage with south facing window that stay 40-60 deg f which seems to be a confusing temperature regarding dormancy. I would consider this over-protecting.

Sometimes I get the impression from those offering their opinions that I need to keep these plants between 25 and 40 deg F or they will either die or screw up dormancy. If that is true I'm not even sure I want to stay with this hobby...I'm not invested enough set up some sort of thermostat thing...and I don't want my trees to be pampered or babied.

Other times I read things like " bonsai are much more tolerant to cold than people think." But as a beginner with no teacher to rely on, I don't even know "what I think" yet.

Is there any way to know what is sufficient without just risking everything?

This is in regard to young plants 0-5 years old. If you need more specifics I'll answer, but I didn't want to go TMI.

Thanks

 

[RJG2]

It highly depends on species. For zone 5, if you stick to zone 4 trees, you can probably just set them on the ground in the winter.

Some mulch or leaves up to the rim of the pot would be enough protection.

If you want to grow zone 7 trees, you'd want to do something like your garage, but keep it at the appropriate temperature somehow (open a window when it gets too warm - there are ways to do this automatically).

 

[rockm]

I have read over and over in books and online " X bonsai trees need winter protection under X deg F," and such.

Does this mean I need to keep them in a place that will not drop below that ambient temperature, or that they will be ok in those lower temperatures so long as I provide protection via some of the many techniques one can read about?

I am in zone 5/6. I have 2 options for winter:

1. cheap poly greenhouse that stays the same temp as outside, but protects from wind. Here they are exposed to "dangerous temperatures," but at the same time they are "protected."
2. my garage with south facing window that stay 40-60 deg f which seems to be a confusing temperature regarding dormancy. I would consider this over-protecting.

Sometimes I get the impression from those offering their opinions that I need to keep these plants between 25 and 40 deg F or they will either die or screw up dormancy. If that is true I'm not even sure I want to stay with this hobby...I'm not invested enough set up some sort of thermostat thing...and I don't want my trees to be pampered or babied.

Other times I read things like " bonsai are much more tolerant to cold than people think." But as a beginner with no teacher to rely on, I don't even know "what I think" yet.

Is there any way to know what is sufficient without just risking everything?

This is in regard to young plants 0-5 years old. If you need more specifics I'll answer, but I didn't want to go TMI.

Thanks

You need to fill out your geographic location for starters. Then explain what species you have or want. Both are critical to winter care--tropical species--ficus, schefflera for instance) don't go dormant in the winter and can be killed by freezing. Temperate zone species, maple, elm, pines, actually REQUIRE some winter pause in growth (dormancy)--but exposure to extremes, like below 0 F, can kill them if it lasts long enough.

 

[Eckhoffw]

Like @RJG2 said, buy species that are plenty hardy in your zone. If you don’t want to invest in a controlled environment -heated cold frame I. E. - then is is the way.
Remember, once it’s in a bonsai pot, your trees will be more vulnerable, and therefore less hardy by a zone or more.
Tropicals are a bit easier to accommodate in that you just need to provide light and necessary humidity inside.

 

[Joe2758]

Alright great; I'm very happy to get some specific advice! I live in central PA. Listed as zone 6, but a local greenhouse owner says it's closer to 5.

I have 5 year old shimpaku junipers that are doing fine in the greenhouse that has gotten into the single digits.

I have some nursery stock boxwoods that were getting cold damage in the green house so I brought those in the garage. I have a nice nursery stock crepe myrtle that I kept in the garage and did well. I left a nursery stock dogwood to the elements and it died (it wasnt very healthy). I kept my JBP and yaupon holly in the cold garage to be safe; they are doing well.

Mostly I have seedlings aged 0-2 years: Trident, jpk, scotch pine, euro beech, korean hornbeam, ginkgo, chinese elm

forsythia and cotoneaster cuttings.

So because most of the seedlings germinated very late in this season, they stayed in the garage with grow light and went dormant for a couple months...Now growing again.

Next year they will need to face the real world... So my question mostly pertains to that.

 

[Eckhoffw]

Looks like you have a nice collection of trees already.
I imagine you’ll soon find out how much protection these trees need.
The boxwoods I would think would be just fine outside I don’t know why they would get damaged in your region.
JBP , yeah gunna need some protection.
Seedling and cuttings would be fine inside till they get rolling in spring.

 

[Joe2758]

Thanks! Well it will be..if they live to be a year old at least lol!

the boxwood thing was weird; I got them at local nursery. The leaves basically looked like they got freeze-dried. I left them out thinking "if anything will be ok, it's these."

I guess next winter I will have enough seedlings to try multiple things...but it would be a pain having more areas to tend to. Plus, even though I have a lot of seedlings- i'd rather be able to select the ones i want rather than just what survives.

Must just be something everyone has to figure out for themselves.

 

[Ininaatigoons]

Protection from wind is good. Wind is one drying factor. Drying is what kills the plants at least until 15 degrees or whatever the temperature is for intracellular freezing in a specific species. Rule of thumb is 15 for temperate climate trees. Evergreengardenworks.com has some great articles and a couple on winter care. Don't forget to chech out his trees! Great place to buy cuttings.

 

[dbonsaiw]

I'm in 7B, so warmer than you, but have most of my trees in/under lots of mulch and a little wind barrier. I also have a JM just sitting on the ground, and my sons' junipers are the same. It's been fairly wet here, but I still water about every 3 weeks/month.

The advice on this site is great, but I found it difficult to understand what was actually being said and to get comfortable with the various processes until I actually did it myself and made mistakes. Having the opportunity to actually see my trees wake up in the spring and reflect back on the winter/protection afforded has taught me a tremendous amount. Definitely has given me more comfort on the zone-appropriate trees and helped me weed out the trees I shouldn't be working with on the south shore of Long Island.

 

[rockm]

Thanks! Well it will be..if they live to be a year old at least lol!

the boxwood thing was weird; I got them at local nursery. The leaves basically looked like they got freeze-dried. I left them out thinking "if anything will be ok, it's these."

I guess next winter I will have enough seedlings to try multiple things...but it would be a pain having more areas to tend to. Plus, even though I have a lot of seedlings- i'd rather be able to select the ones i want rather than just what survives.

Must just be something everyone has to figure out for themselves.

Boxwood is extremely tough, BUT leave them out in the wind with little water and they will get freeze dried foliage--Boxwood foliage will also "bronze"--turn a coppery color or similar in cold weather. That bronzing isn't really a problem as foliage can return to green when the weather warms up. The dried roots, however, are a huge problem.

Wanting to be able to choose which species you can successfully keep is a difficult thing. Choosing species that aren't hardy in your zone can complicate overwintering requirements exponentially. Rule of thumb is that if local landscape nurseries sell a species, it's probably hardy in your area. Trees native to your area are ALWAYS able to handle your winter conditions...

 

[August]

Boxwood is extremely tough, BUT leave them out in the wind with little water and they will get freeze dried foliage--Boxwood foliage will also "bronze"--turn a coppery color or similar in cold weather. That bronzing isn't really a problem as foliage can return to green when the weather warms up. The dried roots, however, are a huge problem.

I'd love to jump off of this to add that yellow / crispy foliage on a boxwood is dead and gone. Living in Colorado, I see lots of this on boxwoods out here and it really is the cold, dry winds / high uv index that does it here. A healthy dormant boxwood will have bronzing, almost dark green - purplish cast to the leaves.

 

[Joe2758]

The foliage is green, but completely crunchy. A couple leaves sort of popped like popcorn. So the leaves seem completely dead, but they are normal color. Been that way probably a month. Anyway, did you mean the crispy foliage itself is gone but the plant might recover, or the plant is dead and gone? It was a very lucky nursery find. I don't THINK the roots dried out, but I'm not sure what was happening deeper down in the nursery pot.

 

[August]

The foliage is green, but completely crunchy. A couple leaves sort of popped like popcorn. So the leaves seem completely dead, but they are normal color. Been that way probably a month. Anyway, did you mean the crispy foliage itself is gone but the plant might recover, or the plant is dead and gone? It was a very lucky nursery find. I don't THINK the roots dried out, but I'm not sure what was happening deeper down in the nursery pot.

Leaves specifically. If it's crunchy same thing. You'll end up with big dead patches like a thuja but otherwise is not a direct sign that the roots have taken any damage

 

[Joe2758]

oh no, dead patches that won't come back? The cambium was green everywhere i checked. I hope if it recovers it will go back to normal or back bud

 

[Gabler]

Even here in zone 7, I’ve had trouble with boxwoods’ winter hardiness. They‘re fine in the ground as a shrubbery, but in pots they suffer from the cold, even when said pots are buried in the ground. Although the foliage is damaged, the branches are fine. I just get a lot of half-dead leaves every winter. It’s likely that in zone 6, on the border of zone 5, your cold damage is a bit more severe. Expect some branch dieback.

 

[rockm]

The foliage is green, but completely crunchy. A couple leaves sort of popped like popcorn. So the leaves seem completely dead, but they are normal color. Been that way probably a month. Anyway, did you mean the crispy foliage itself is gone but the plant might recover, or the plant is dead and gone? It was a very lucky nursery find. I don't THINK the roots dried out, but I'm not sure what was happening deeper down in the nursery pot.

Crunchy leaves mean there's a problem with the roots being unable to transport water to them adequately. The reasons can be many--from underwatered soil, to wind drawing moisture out of the leaves while roots are frozen and unable to push water up to the leaves. Dead foliage in winter most always boils down to root issues. The plant can recover, but not always. If the roots supporting that dried out foliage are dead, then chances are reduced.

FWIW, I have overwintered boxwood for decades simply by putting their pots well under mulch (ensuring they're watered well before mulching and watering the mulch thoroughly as it is piled on--dry mulch can draw moisture out of the soil in pots). My overwintered trees are exposed to rain and snow, which usually keeps the roots from drying out. If you're storing trees in a covered structure, like a garage, boxwood, and all other trees, need to be monitored and watered when they need it.

 

[Joe2758]

Let me know if I should start a new thread for this, but:

1. I have ginkgo, korean HB, trident seedlings that I would like to plant in the ground this spring....maybe 6 weeks from now? They germinated out of season, so they are the very awkward age of around 7 months. They did all have a short dormancy period and are growing nicely now. Do I need to wait til next year?

2. I have a whole lot more seeds that are on the correct schedule to be planted. Any reason I can't just plant them in the ground and maybe cut the tap root next year? those will be beech, more K HB. more tridents, scotch pine, larch....THey should all be hardy. '

Basically, I over-did it on the seeds.

Sources I ready say I should wait until they are a year old all the way to 3 years old. That seems weird to me? I have a nice fenced in garden area I would like to use to unload some of these trays.

 

[rockm]

I'd wonder why it would be "better" to wait to plant them next year...other than the danger presented by rabbits/deer/four legged browsing animals.

Spring is a good time to plant stuff (if you can keep the critters off of them). Early to mid autumn can be better--soil is already warm from summer, in spring it's warming up from winter.

 

[Gabler]

Let me know if I should start a new thread for this, but:

1. I have ginkgo, korean HB, trident seedlings that I would like to plant in the ground this spring....maybe 6 weeks from now? They germinated out of season, so they are the very awkward age of around 7 months. They did all have a short dormancy period and are growing nicely now. Do I need to wait til next year?

2. I have a whole lot more seeds that are on the correct schedule to be planted. Any reason I can't just plant them in the ground and maybe cut the tap root next year? those will be beech, more K HB. more tridents, scotch pine, larch....THey should all be hardy. '

Basically, I over-did it on the seeds.

Sources I ready say I should wait until they are a year old all the way to 3 years old. That seems weird to me? I have a nice fenced in garden area I would like to use to unload some of these trays.

Generally, it’s good forum etiquette to start a new thread for a new question, rather than hijack someone else’ thread. That said, I’ve been known to go off on tangents about loosely-related topics based on a single prior comment in a thread, so I doubt this is a real problem for anyone.

 

[Joe2758]

Oh I just figured because it was my own thread is why i asked, but I guess it makes sense for people who might be browsing for topics. I'll remember for next time, thanks!

To Rockm: regarding the seedlings, one concern I had was simply based on contradictory internet advice. Some said they should be a year before planting in the ground, one thing I read said 3! It doesn't make sense to me, but a lot of things that didn't make sense to me before make sense now.

The primary reason I am second guessing it is because of their awkward age...I wasn't sure if they would be more sensitive in the (next) winter because of that.

I am leaning toward putting most of my seedlings and planting my stratified seeds right into the ground come spring. It is fenced in, so it is safe in that way.

I might get a shade screen though since they are growing right now and have "indoor leaves." I wouldnt want to scorch them since they are only now putting out their 1st and second leaf pairs since dormancy