The right amount of UV can help reduce latent fungal and bacterial loads. If it is applied to tropical trees, for example, they are more likely to retain their UV hardiness and experience a better transition out of winter storage to spring outdoor exposure.
I learned something new today. Thanks!The right amount of UV can help reduce latent fungal and bacterial loads. If it is applied to tropical trees, for example, they are more likely to retain their UV hardiness and experience a better transition out of winter storage to spring outdoor exposure.
Every year I’ve started fruit and vegetable seedlings indoors I’ve had quite a song and dance in gradually exposing them to UV. For other gardeners this shuffle and anxiety should be pretty apparent
wouldn’t brick remove heat ? Gravel is a good idea , or what about placing pots into plastic nursery trays on the ground, they are alittle elevated and create some space for drainage. But yeah wouldn’t brick or a stone remove heat or is that insulated once you put mulch around it. What about if you just put on grass, till you need mulch , I didn’t think that would cause too much blockage from drainage unless your pot has no feet.
A heat sink is what you want. The whole point of putting the pots on the ground is thermal stability. What you don’t want is for the roots to freeze and thaw and freeze again repeatedly. That kills trees.
I meant wouldn’t brick remove heat. I understand putting pots on ground which is what I do, but isn’t placing pots on brick counterintuitive?
In putting the pot on the ground, mulching it in, and perhaps also using some sort of structure as a windbreak, we’re doing our best to reduce convective heat transfer with the air. The reason we want to prevent heat transfer with air to the extent possible is because air temperature is highly variable. The difference between the high and low air temperature on a typical day is often 20 degrees Fahrenheit or more. It might be 45 F at noon and 25 F at midnight. If our soil temperature fluctuated with the air temperature, we’d be in big trouble with roots freezing and thawing over and over, causing frost damage and causing trees to come out of dormancy too early. What’s the difference between the daily high and low temperatures of the ground? Not much. So, if we have our bonsai pots in thermal contact with the ground and insulated from the air with a layer of mulch, we can expect to maintain a stable temperature. Like earth, brick is an insulator with a high heat capacity. Brick on earth is going to be in thermal equilibrium with the earth for the most part. The temperature of the brick will be stable, changing slowly with respect to changes in ambient air temperature. The pot and the brick will be in thermal equilibrium for the most part. When contact with the air heats the pot up so that it is a little warmer than the brick, heat will be transferred from pot to brick. When contact with the air chills the pot so it is colder than the brick, heat will be transferred from the brick to the pot.
I know how winter protection works. I’m just questioning whether placing the pot on a brick on the ground , is going to have same heat stability as just placing the pot on the ground in direct contact. I don’t think it will have equilibrium with the thermal heat of the earth.
I think your argument Is valid. Although, a cement block will be thoroughly climate neutral after a while in contact with the ground. To elevate it with a block off the ground seems counterproductive though. Especially when your Mulching around and over the pot. 2 years ago i had to wait until 3-4” of ice around my plants thawed to get them out. About 30 plants with no casualties.
I’m not aware of a conifer that cannot go below zone 8b. That seems like the tree’s upper range of winter temps, e.g. “above this it won’t have enough of a dormancy period.”
It's going to be pretty darn close to the same. What are bricks made of? Earth. That said, I wouldn't go out and buy a bunch of bricks if you didn't already have an area with something like that. The suggested purpose for putting the pots on brick was drainage. Well, there are other ways to ensure good drainage. My pots go on the ground in an area where there is already a layer of cypress mulch on the ground. The pots drain well enough sitting on that. Works for me in zone 5b.
Yeah mine are placed on ground in big nursery trays if they are smaller pots , so there is some buffer with pot and ground to let better drainage,bigger pots are just touching ground directly , next to my house with burlap and wood pallets for wind block. When it get colder I’ll use mulch packed in around pots. 5b is way colder than 6b.
I get what your saying,but cannot help to wonder if he would say differently if he had no way of providing this light during dormancy.
Absolutely. None of that was “it’s not possible” or “it’s bad” but “there’s better”I get what your saying,but cannot help to wonder if he would say differently if he had no way of providing this light during dormancy.
In reality To me,I say yes of course.If I had the proper setup like a cold greenhouse that I imagine Ryan has access too.
I could be envyous though
There is biology vss practicallity. For a long time in biology it is know that photosynthesis in winter takes place through the bark. When I was a student a few decades back this was already taught. Only bonsai people seem to think that life stops in winter. It does not. Next to this, plants use length of day as a co-trigger for spring. So providing natural light to the tree sounds like a logical thing to do.
I think you're overthinking it. The bricks are going to be pretty much the same temp as the foot of mulch on top of them. The reason for them is simply to insure drainage. I would not place pots directly onto grass, mulch etc. Pots settle over time into less firm surfaces, particularly when it's wet. The weight of a pot full of rain, combined with softened ground, can push the feet into the ground. The bricks provide more surface area to support that weight.
Pinus massoniana aka Chinese Red pine. 6400 T5 54W grow lights. 8 of them in a four foot fixture. They’re getting about 9 hours of light. The lights are about 12 inches away from the tallest ones. I do have a gentle fan that I turn on about every other day. I germinated them when I was in south Ga and now I’ve moved to North Alabama. They got their first low thirty degrees weather and most of them turned slightly purple. Some of the smaller cuttings actually turned brown on me.
Neat! Those look generally okay. I’d keep the fans going constantly to reduce fungal risk, increase plant respiration, and to make the growth a bit stronger (without wind they end up spindly and easily broken).
Yes…For most of the winter,even where I’m at is 7 I believe.
Thanks for the response. I’m kinda new to this in a sense. I bought the literati bonsai book and a good bit of those were of this species so I figured I’d give it a shot. It’s already been in the mid 20s here about 5-7 days. So I’m not sure they can handle the winter. Not sure what to do honestly. I just bumped the light duration Dow a bit as I’m trying to mimic what nature is during. I will need to get an oscillating fan I think. I will potentially just put them in the garage with no light. I could put them outside but Sheffield’s says minimum hardiness is an 8. Love to hear your thoughts and advice. I don’t plan on keeping them under grow lights every year. Just wasn’t sure what to do after they got some cold weather and turned purple.Neat! Those look generally okay. I’d keep the fans going constantly to reduce fungal risk, increase plant respiration, and to make the growth a bit stronger (without wind they end up spindly and easily broken).
I’ve had pine seedlings turn purple before and they just seemed weak and like they were harboring disease. Hang on to those ones at your own risk
Are you planning to do this just this winter? Those seem like trees that still need a winter dormancy period, so I’d plan to keep them outside in future winters (but you do you). In the nursery trades, propagation literature says you can generally “force” trees through two consecutive seasons without much of a dormancy period, but you’re possibly pushing your luck.
The color and intensity of your lighting are great, but I question the duration. Are you intending for the 9-hour periods to be brief, like for the next couple of weeks? It seems like the worst of both worlds — all this effort to keep them going over the winter but short photoperiods that will keep them a bit weak and lethargic. I’d aim to increase the duration of light by one hour every other week.
I’m excited to see what you come up with! I can tell you’re putting a lot of thought into it. Cheers.
Ohh, gotcha.
