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Starting tree seedlings indoors with heat source

Hoytvectrix

5 year old buck +
I currently have chestnuts and acorns in soilless media in the fridge and am starting to get some emergence. I would like to get some potted (likely in rootmakers) to get them as big as possible before the spring. I have a south facing room that gets plenty of light but the room is consistently around 67 degrees. Should I go with heat mats with thermostats, supplemental heat lamps, or go with a space heater and led lights? Budget is probably around $200 and I will have as many as 100 seedlings.
 

Telemark

5 year old buck +
I would not use any heat at all. With limited sunlight in winter, you want the trees to grow as slowly as possible. Heat will cause them to grow quickly, but the lack of sunlight will cause them to grow weak and spindly.

If anything, I would add light without adding any heat.
 

Sconnie

5 year old buck +
I have done this in my basement “grow area” as my wife calls it. Heat may be needed for germination but that is it. High powered lights for up to 16 hours a day are a must.

The one thing I’d mention is a small fan blowing on the seedlings once they emerge. This mimics the wind and forces the seedlings to grow more robust stems!

Don’t start them too soon for your area. Those acorns have a lot of germ in them to really send growth up fast.

Finally, be careful when moving them outside. The sun and wind can be too strong at first , you need to acclimate them slowly.

Good luck and have fun with it!


Sent from my iPhone using Tapatalk
 

williams111

5 year old buck +
I did this a couple years ago, had great success getting them growing well. I did have heating mats and adjustable height 4' led Lights over them. Mine didn't seem to get too tall and spindly because I was able to lower the lights down an inch or 2 above the pots then progressively moved them up as the seedlings grew. The issue I ran into was the fungus gnats. Do any of you have a good remedy for the gnats? If I remember correctly a concoction of water/peroxide was supposed to help, but if you missed even one gnat they would lay more eggs and the battle would start over. Overwatering likely contributed to this issue. I have been debating starting a few indoors this year, but I am hesitant because of the gnats.
 

BuckSutherland

5 year old buck +
I tried growing some trees in the basement a few winters ago. Turned out being a colossal flop for me. Just much easier to go and buy some trees in the spring or do direct seeding in the fall and tube.


Great idea, kinda fun, but awful results for me.
 

Turkey Creek

5 year old buck +
I did this a couple years ago, had great success getting them growing well. I did have heating mats and adjustable height 4' led Lights over them. Mine didn't seem to get too tall and spindly because I was able to lower the lights down an inch or 2 above the pots then progressively moved them up as the seedlings grew. The issue I ran into was the fungus gnats. Do any of you have a good remedy for the gnats? If I remember correctly a concoction of water/peroxide was supposed to help, but if you missed even one gnat they would lay more eggs and the battle would start over. Overwatering likely contributed to this issue. I have been debating starting a few indoors this year, but I am hesitant because of the gnats.
There is a product called Gnatrol that is a soil drench. It works good at killing the eggs, usually applied once a week. The yellow sticky cards will catch most of the already hatched adults.
 

b116757

5 year old buck +
I struggle with getting them hardened off to go outdoors without killing them. So I just direct seed or start them outdoors in RM18’s in the spring. This year I will be direct seeding quite a few STO but probably use RM18’s on some American Chestnuts on the patio. It is fun to grow them indoors under grow lights if you can get them hardened off successfully.
 

BigGame

Buck Fawn
A good way too kill those gnats is by watering your plants with sevin. I started some apple trees from seed in the house and they became infested gnats. After watering them with sevin for a couple of weeks they are completely gone.
 

Telemark

5 year old buck +
I struggle with getting them hardened off to go outdoors without killing them

You have to take them outside and back inside for a week or two.
 

b116757

5 year old buck +
You have to take them outside and back inside for a week or two.
Yes but you also have to remember them once you do this if you forget them to early process well…☠️☠️ as I said I struggle at this better for me at least to avoid it.
 

cavey

5 year old buck +
I have done this in my basement “grow area” as my wife calls it. Heat may be needed for germination but that is it. High powered lights for up to 16 hours a day are a must.

The one thing I’d mention is a small fan blowing on the seedlings once they emerge. This mimics the wind and forces the seedlings to grow more robust stems!

Don’t start them too soon for your area. Those acorns have a lot of germ in them to really send growth up fast.

Finally, be careful when moving them outside. The sun and wind can be too strong at first , you need to acclimate them slowly.

Good luck and have fun with it!


Sent from my iPhone using Tapatalk
I like the fan Idea - might have to try that.

I used a freestanding 7' tall ish storage rack/shelf set up, took out all the shelves but the a top middle and bottom shelf. I put my grow lights under the top and middle shelves on chains and S hooks so I could raise the lights up as the chestnuts grew, worked very well. My only problem was I had a very high nut germination percentage and ended up with nearly a hundred trees under the lights - that worked well initially when they were in solo cups but with each pot change out the space on the shelves got tighter and tighter. I did this in a corner of my utility room in the basement - through the windows it looked like a minor league pot grow operation. In the end I had to rotate pots under the shelf lights as I had pots on the floor, the trees out grew the shelf space and it was too early to move them out into the unheated garage. They grow a hell of a lot faster than you would expect.
 

yoderjac

5 year old buck +
I currently have chestnuts and acorns in soilless media in the fridge and am starting to get some emergence. I would like to get some potted (likely in rootmakers) to get them as big as possible before the spring. I have a south facing room that gets plenty of light but the room is consistently around 67 degrees. Should I go with heat mats with thermostats, supplemental heat lamps, or go with a space heater and led lights? Budget is probably around $200 and I will have as many as 100 seedlings.

Dr. Whitcomb warns against trying to start trees early in a greenhouse. The angle of the sun is to low with short days. They tops may look ok, but you get very poor root development. I actually have a real life experience with this. The year I started pawpaws indoors under lights, another guy started them the same time using the same rootmaker containers with the same methods but did it in a heat controlled greenhouse. We compared pictures. They looked the same on top. My root systems are very dense with many terminal root tips. His were so poor many of his trees died after transplant to the next larger container in the spring.

For trees, you don't need fancy grow lights. The key is using lights with high lumens that are cool. I used fluorescent shop lights for many years, but they now make similar shop lights with LED tubs that work even better. Light energy diminishes with the distance squared. With hot grow lights (sodium, halogen...) you have to keep the lights far from the plants. With my shop lights you can keep them very close because they don't produce much heat. This provides a lot of light intensity for the tree seedlings. This is also why I like the rootmaker express trays. I can reorganize my trees based on height. I then hand the shop lights at an angle so they are equidistant from the tops of all the seedlings. You can do this with chains or cord with prussic knots and adjust as needed.

Shop lights are inexpensive. The light color is not important. Fancy grow bulbs produce light at specific wavelengths that plants use at different stages of growth. This helps for indoor plants, but not for starting trees. They spend such a small part of their life indoors and for much of it energy is coming from the nut. The are not really affected by light color but they are very impacted by the light intensity. Cheap shop lights are the way to go. I found 3 to 4 shop lights hung about 3"-4" apart will cover about 6 express trays. That covers around 100 nuts. You will cull significantly by the time you move to 1 gal RB2s in the spring.

As for heat, I just used scrap lumber to build small grow rooms and covered them with shower curtains and duct tape. I put a small oil filled heater in each along with an atomizing (misting) humidifier.

Keep in mind that root pruning is a series of containers, not a single container. I dried planting directly from 18s in the spring and not a single tree survived. You need to transplant them to 1 gal RB2s after 12-16 weeks when the 18s are filled with roots. Then transplant them again in the summer into 3 gal RB2s. They do OK in my region if planted after they have filled 1 gal RB2s, but really thrive when planted after being transplanted to and filling 3 gal RB2s. You may or may not benefit from overwintering them and keeping them for a second growing season depending on your region. I'm in zone 7a.

There are many threads on here from my early days of growing chestnuts indoors that you can benefit from. One key is how you water and using rain water if at all possible.

Thanks,

Jack
 

Hoytvectrix

5 year old buck +
Dr. Whitcomb warns against trying to start trees early in a greenhouse. The angle of the sun is to low with short days. They tops may look ok, but you get very poor root development. I actually have a real life experience with this. The year I started pawpaws indoors under lights, another guy started them the same time using the same rootmaker containers with the same methods but did it in a heat controlled greenhouse. We compared pictures. They looked the same on top. My root systems are very dense with many terminal root tips. His were so poor many of his trees died after transplant to the next larger container in the spring.

For trees, you don't need fancy grow lights. The key is using lights with high lumens that are cool. I used fluorescent shop lights for many years, but they now make similar shop lights with LED tubs that work even better. Light energy diminishes with the distance squared. With hot grow lights (sodium, halogen...) you have to keep the lights far from the plants. With my shop lights you can keep them very close because they don't produce much heat. This provides a lot of light intensity for the tree seedlings. This is also why I like the rootmaker express trays. I can reorganize my trees based on height. I then hand the shop lights at an angle so they are equidistant from the tops of all the seedlings. You can do this with chains or cord with prussic knots and adjust as needed.

Shop lights are inexpensive. The light color is not important. Fancy grow bulbs produce light at specific wavelengths that plants use at different stages of growth. This helps for indoor plants, but not for starting trees. They spend such a small part of their life indoors and for much of it energy is coming from the nut. The are not really affected by light color but they are very impacted by the light intensity. Cheap shop lights are the way to go. I found 3 to 4 shop lights hung about 3"-4" apart will cover about 6 express trays. That covers around 100 nuts. You will cull significantly by the time you move to 1 gal RB2s in the spring.

As for heat, I just used scrap lumber to build small grow rooms and covered them with shower curtains and duct tape. I put a small oil filled heater in each along with an atomizing (misting) humidifier.

Keep in mind that root pruning is a series of containers, not a single container. I dried planting directly from 18s in the spring and not a single tree survived. You need to transplant them to 1 gal RB2s after 12-16 weeks when the 18s are filled with roots. Then transplant them again in the summer into 3 gal RB2s. They do OK in my region if planted after they have filled 1 gal RB2s, but really thrive when planted after being transplanted to and filling 3 gal RB2s. You may or may not benefit from overwintering them and keeping them for a second growing season depending on your region. I'm in zone 7a.

There are many threads on here from my early days of growing chestnuts indoors that you can benefit from. One key is how you water and using rain water if at all possible.

Thanks,

Jack
Thanks for the detailed response, Jack. I think I am going to go with the shop lighting using LED lights and some heat mats. I found and had read the threads you had mentioned. Initially, I was thinking that I got enough light that my main concern was heat, but I think I will cover my bases and supply both with timers.

I know that I will probably end up culling quite a few seedlings, but at this point this is more of a project to keep busy in the late winter/early spring than anything else.
 

yoderjac

5 year old buck +
Thanks for the detailed response, Jack. I think I am going to go with the shop lighting using LED lights and some heat mats. I found and had read the threads you had mentioned. Initially, I was thinking that I got enough light that my main concern was heat, but I think I will cover my bases and supply both with timers.

I know that I will probably end up culling quite a few seedlings, but at this point this is more of a project to keep busy in the late winter/early spring than anything else.

I found 15 hour days worked well. Heat mats will work, but keep in mind you need air space below the 18s so the heating will be convection only, not conduction.

Starting chestnuts indoors under lights had been a great cabin fever project for me over the years. IT was a great learning opportunity and kept me busy with a habitat project when my arthritis would not permit much outdoor activity.

Enjoy the journey!
 

Robert799

A good 3 year old buck
I have used the root makers before… but don’t have much success in getting a good root mass. I use the adjustable lights, heating pad etc. what’s the soil you use? I have used primarily Scotts potting soil.
 

yoderjac

5 year old buck +
I have used the root makers before… but don’t have much success in getting a good root mass. I use the adjustable lights, heating pad etc. what’s the soil you use? I have used primarily Scotts potting soil.

Big box store potting soils don't work well with rootmakers. The idea is that roots are air pruned which forces up stream branching. You need space for the roots. You need a chunky professional type mix designed for trees. Most have quite a bit of pine bark. You can also make your own. As I recall, Whitcomb had a recipe for it in one of the papers. I just use Promix and it works fine.

When you water chestnuts in rootmakers, you totally drench them. Water should be running out of the bottom holes of the 18s. They don't like wet feet, so, you don't water them again until they dry out. When you first plant them water will run out the bottom holes quickly because the Promix is chunky and does not compact. As they grow, roots will begin to fill all those air pockets in the container and they will become harder to water. Eventually you will need to pour a little water on tome and wait for it to soak in, then pour more in and wait. You will repeat this until water comes out the holes which means they are drenched. At about 16 weeks they will become so hard to water that you know the roots have filled the 18 cell and it is time to transplant to 1 gal RB2s. You want to avoid any mix that retains water. Chestnuts want to be drenched and then dry out.

For frequency of watering, I like to "water by weight". This is describe in some of my chestnut threads. You can't water on a time table as they will use different amounts of water at different stages of growth. As you gain experience, you can tell by looking at the seedlings. If you see the leaves begin to visibly droop you've waited too long and they need watered immediately. They leaves should stand back up by the next day after drenching.

It takes about 12-16 weeks for them to fill the cell. 12 is on the early side for most and 16 is on the late side. The other consideration is fertilizer. Whitcomb recommends Osmocote and MicroMax. That works great but I found it is more convenient to just buy Osmocote Plus. It has most of the micros that MicroMax has. You sprinkle the mix on top of the cells. It is a slow release fertilizer that will release the nutrients about the time the nut had been exhausted.

If poor root development is coming from a lack of light, you may not be hanging your lights close enough. With LEDs I try to keep them about 3 " above the trees organized by height and hung at and angle. If you put express trays 2 across and 3 deep, 4 shop lights hung close together should be plenty of light for them.

Timing is a consideration. If you are growing lots of trees, it is hard to move them in and out doors to acclimate them. I start with my last frost date and work backwards. I want to transplant from 18s to 1 gal RB2 containers just as I'm putting them outdoors. For the same number of trees, the 1 gals will take up a lot more space. I work back from the date I want to transplant and begin acclimating them 16 weeks. I then back off 60-90 days to add moisture to the nuts to start cold stratification. I have an upper and lower deck. The lower deck gets a little morning sun and is largely shaded in the afternoon. I put them there for several weeks. I slowly move them to the upper deck a few at a time after a few weeks. If I see any sign of sun scald, I wait longer before moving the next few up.

Hope this helps,

Jack
 
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