3 Gallon Air Pot

[KSQ2]

I really like the price of these 3 gallon pots. My only concern is the dimensions. They look to be 10" height and diameter. That doesn't seem like it would be 3 gallons; am I way off on that?

https://www.amazon.com/GROW-GREEN-P...3+gallonroot+pruning+pots,aps,134&sr=8-5&th=1

 

[yoderjac]

None of the 3 gal containers are actually 3 gal. It is a nominal measurement like dimensional lumber.

I don't know what the bottom of those pots look like. From what I can see in the picture, the protrusions with the holes are horizontal. I haven't used those pots, so I can't speak to the effectiveness. The rootmaker RB2 containers have protrusions that angle downward and out to direct lateral roots that hit the side. The bottoms of RB2s are concave at the bottom and high in the center with ridges growing outward to the lowest row of protrusions. When roots hit the bottom of the container, they are directed out and down toward one of the protrusions where they are air pruned.

As I say, I don't know how well or poorly the pots in the link work, but these are design issues to look at for a comparison. Maybe others have used that brand of pots and can give you a hands-on perspective.

 

[KSQ2]

Will one of the 3 gallon pots hold a tree for 2 years, after starting them in R18s? Or will they need to be planted after one year of growth? I don’t plan to move them into bigger pots than the 3 gallons.

 

[yoderjac]

Will one of the 3 gallon pots hold a tree for 2 years, after starting them in R18s? Or will they need to be planted after one year of growth? I don’t plan to move them into bigger pots than the 3 gallons.

I never used containers larger than 3 gal RB2s. I would start my trees in the winter indoors. I would transplant them to 1 gal containers in mid-April when I would acclimate them to the outdoors on my decks. (starting on a lower deck with only a little morning sun and eventually moving to the upper deck with full sun).

My fastest growing chest nuts would fill the 1 gal RB2s by mid-summer. By fall, they would fill 3 gal RB2s and be ready for field transplant. I had some trees that were almost 5' tall 1/2" inch in diameter by mid-summer. With my growing season, many of my slower growing chestnuts would not fill the 3 gal RB2s by fall. I overwintered those trees in a cold room and gave them a second growing season on my deck.

So, some will depend on your growing season and the genetics of individual trees.

 

[KSQ2]

I never used containers larger than 3 gal RB2s. I would start my trees in the winter indoors. I would transplant them to 1 gal containers in mid-April when I would acclimate them to the outdoors on my decks. (starting on a lower deck with only a little morning sun and eventually moving to the upper deck with full sun).

My fastest growing chest nuts would fill the 1 gal RB2s by mid-summer. By fall, they would fill 3 gal RB2s and be ready for field transplant. I had some trees that were almost 5' tall 1/2" inch in diameter by mid-summer. With my growing season, many of my slower growing chestnuts would not fill the 3 gal RB2s by fall. I overwintered those trees in a cold room and gave them a second growing season on my deck.

So, some will depend on your growing season and the genetics of individual trees.

I have a few square one gallon root containers and also some round ones. If you advise to use those, I’ll do so and await the 3 gallons like you. Does the smaller container promote more root growth? Or is it just easier to water them in the smaller container?

 

[yoderjac]

Dr. Whitcomb did some research that says that most of the root branching occurs in the first 4 inches above the prune. It is not exact. So the idea is to pick a container that has room for about 4" of growth on all sides of the existing root ball from the previous container. 1 gal containers are a bit on the small side when going from 18s and 3 gal are a little on the large side. I found that I get the fastest growth by using both, but it is more work to do 2 transplants.

I have planted in the field from one gal containers. Most of the trees survive and some of them will thrive. If I wait until the roots fill a 3 gal container, almost all trees survive and most of them will thrive.

I don't find 1 gal containers any easier or harder to water than 3 gal. They are certainly lighter to move around and dunk, but I don't find 3 gal problematic. When I'm top-watering, I find no difference.

 

[KSQ2]

Dr. Whitcomb did some research that says that most of the root branching occurs in the first 4 inches above the prune. It is not exact. So the idea is to pick a container that has room for about 4" of growth on all sides of the existing root ball from the previous container. 1 gal containers are a bit on the small side when going from 18s and 3 gal are a little on the large side. I found that I get the fastest growth by using both, but it is more work to do 2 transplants.

I have planted in the field from one gal containers. Most of the trees survive and some of them will thrive. If I wait until the roots fill a 3 gal container, almost all trees survive and most of them will thrive.

I don't find 1 gal containers any easier or harder to water than 3 gal. They are certainly lighter to move around and dunk, but I don't find 3 gal problematic. When I'm top-watering, I find no difference.

I did not get the head start you did when starting trees in the winter. We do have a pretty long growing season; however, let’s say our trees don’t fill the 3 gallon containers by fall’s end, and I put them in the garage for the winter. Next year they take off again and fill the 3 gallon containers by July. Am I better off planting them in the field then? Or letting them stay in the 3 gallon containers for the remainder of the growing season? I’d worry about them becoming horribly root bound.

 

[yoderjac]

I did not get the head start you did when starting trees in the winter. We do have a pretty long growing season; however, let’s say our trees don’t fill the 3 gallon containers by fall’s end, and I put them in the garage for the winter. Next year they take off again and fill the 3 gallon containers by July. Am I better off planting them in the field then? Or letting them stay in the 3 gallon containers for the remainder of the growing season? I’d worry about them becoming horribly root bound.

Sounds like a bit of a dilemma. Dr Whitcomb says it is better to transplant a little earlier rather than a little later. On the other hand you are in a pretty arid environment. Bare root trees pretty much have to be planted when they are dormant. Because the root system from an RB2 container is pretty much undisturbed when you field plant it, the tree doesn't need the same time to adapt. Rootmaker trees can be transplanted when growing and they seem to continue to grow almost immediately. The risk is the possible lack of water during the summer. If you have the ability to field water if needed, I think you can plant them as soon as they fill the 3 gal RB2s.

But my guess is that even with your longer growing season, You should be Ok with 2 growing seasons. Since I started in the dead of winter, my first growing season might be a little longer than your first growing season. Of course, your second growing season will be longer than mine. So, I'm think your average trees will be fine in terms of going for 2 seasons in RB2s.

Because of the root pruning containers, the trees don't become root bound in a traditional sense. I think you'll be fine.

 

[RGrizzzz]

A number of the better known chestnut growers start in 1 gallon RMs and use 3 gallon RMs for the second growing season. Consensus say plant in ground after no more than 2 years in pots.

 

[yoderjac]

A number of the better known chestnut growers start in 1 gallon RMs and use 3 gallon RMs for the second growing season. Consensus say plant in ground after no more than 2 years in pots.

Completely agree. With my growing season length, I would need to transplant to containers larger than 3 gal. This isn't really practical for me, and I get such good results planting from 3 gal RB2s, there little benefit and a much higher cost at going beyond 3 gal. I could see cases in a more arid environment where sandy soil dries out to a deeper level and field watering is not possible, where going larger could be a benefit. But at that point, one begins to question if root pruning is a good strategy for that arid of an environment.