Chestnut stratification

[TreeDaddy]

You don't have to wait for the 12 to 16 weeks. At first I thought this was necessary and beneficial, but a 1 gal RB2 is 7" tall and 6.5 inches wide. So, there is still right around 4" on all sides of the tap root. These take a lot more space, so from a practical standpoint, most folks keep them in 18s for the full 12 to 16 weeks indoors and then move to 1 gal when they take them outside. Nothing wrong with this approach, but you get a bit more growth transplanting early rather than waiting. You can't go too large because of the 4" rule.

This is news to me. Where did you get this info?

I thought one was supposed to wait until roots filled the RM18 before moving to larger size. i.e., media removed intact when lifting seedling,etc

bill

 

[yoderjac]

This is news to me. Where did you get this info?

I thought one was supposed to wait until roots filled the RM18 before moving to larger size. i.e., media removed intact when lifting seedling,etc

bill

It comes from piecing a few things together from Dr. Whitcomb's papers. One is on the 4" rule and the other is the one on growing trees from seed.

"As soon as the seedlings have reached the point where the taproot has reached the bottom of the container and has been air-root-pruned, which in turn stimulates secondary roots to form and those in turn were air-root-pruned by the openings on the sides of the RootMaker containers and tertiary branch roots have formed, IT IS TIME TO TRANSPLANT. Do NOT think of how long you can leave the seedlings in these or any other container. DO focus on how SOON the seedlings can be transplanted into the next step in the production sequence."

I can't recall where I got the 12-16 weeks originally. It may have been from a direct email conversation I had with Dr. Whitcomb when I first started.

When you look at the diameter of the 1 gal RB2, you can see that it meets the 4" rule for lateral secondary roots but they are too deep to prune the tap root at 4". Given what Whitcomb says about focusing on "how soon", what is the primary purpose of the 18s? It allows several things. First, it prunes the tap root very effectively at about 4". Second, it makes very efficient use of space and medium. You can get a lot of young seedlings growing in a small space using a modest amount of medium. This lets you cull down to your best trees for transplant into 1 gals.

I think the 12-16 weeks comes from a commercial operation at a nursery where they are balancing practical considerations with growth. In my personal experience, my first year working with Rootmakers, I was shocked how tall the trees were in 18s. Never having done this before, I was concerned that they were outgrowing the containers. At 9 weeks I transplanted them. Medium fell off the root balls in fairly good sized chunks when I did the transplant. They were not close to filling the 18s. In future years, I went to higher volumes and timed the 12-16 week transplants to correspond with our last frost and moving trees outside. I did not have room for early transplant. While I got good growth in subsequent years, none were as big as the trees I transplanted at 9 weeks my first year.

If you look at my "Maximizing Growth With Rootmakers" thread, you will see the second thing I discovered was that transplanting from 1 to 3 gal RB2s in late spring to early summer increased growth. Now that 6' seedling in the thread was not transplanted early from the 18s.

I've got 3 Seguins growing from seed this year. Since I have plenty of room for them, I plan to transplant them to 1 gal RB2s early. I may wait one more week or so. I'll keep the other thread updated so you can see the progress. As long as the 18s prune the tap root, I think the 1 gal RB2s will effectively prune the lateral roots just as well while promoting growth.

Thanks,

Jack

 

[TreeDaddy]

How do you decide when to transplant from 1to 3 gal RBIIs?

bill

 

[98uconn]

98 what part of the country did you plant those chestnuts in? Zone?

I’m in Northeast Pennsylvania


Sent from my iPhone using Tapatalk

 

[yoderjac]

How do you decide when to transplant from 1to 3 gal RBIIs?

bill

I don't have any good standard indicator. It is a judgment call. In general, we are back to when the container is full of roots here. The reason is that there is no overlap between 1 gal and 3 gal RB2s for lateral roots like there is between 18s and 1 gal RB2s. So, you want to make sure roots are pruned. One good indicator is that they become harder to top water because the roots have filled the voids in the container. But like Whitcomb says, too soon is better than too late. It also depends on the type of tree. Chestnuts grow pretty fast. I can't recall the exact dates, but if you go through that maximizing growth thread I probably documented when I did the 1 gal to 3 gal transplant.

Also, I use 1 gal and 3 gal for practical purposes and my climate. To really allow the full 4" on all sides of the root ball, a larger diameter container than the 3 gal is needed. There is a cost consideration for me as well as a practical one. I need to transport trees from my house to the farm and larger containers are more problematic. Also, with my climate, I can't fill a container larger than 3 gal in 1 season. Finally, the 3 gal are a perfect size for my auger. With my heavy clay, I need to protect against roots getting too much water infiltration in the medium and pooling but also need to protect against dry summers. Using a deep hole with drainage below it keep the root ball from sitting in water in the spring and using an auger that is very close to the size of the rootball lets the lateral roots grow into the clay which holds the needed moisture by the time dry summer rolls around.



Thanks,

jack

 

[Cap'n]

In one of Dr Whitcomb’s book he says to use 3 parts mini bark, 1 part peat, one part sand. This is what I’d did last year after I ran out of Promix. The sand was hydrophobic though, when I was potting some trees into 1 gal I would dunk the whole pot in a rain barrel until the air bubbles stopped and then put it on a rack to drain back in the barrel. I accidentally knocked one off and it spilled a lot of the media. That’s when I noticed the sand was dry as a popcorn fart. Even though I’d held it basically under water. I have a granular soil wetting agent called Rely II. I applied that to all of my containers so the sand would except water. It did remedy the situation.
Also I read that if your bark is not composted that it will draw the nitrogen out of the soil. I knew that could happen with wood chips and mulch that’s just ground up pallets. But I was under the assumption bark was different than the rest of the tree. I imagine that’s why he recommends using the slow release fert in the mix. Do y’all compost your bark or go straight from the bag? Or have you ever heard of that?

 

[yoderjac]

In one of Dr Whitcomb’s book he says to use 3 parts mini bark, 1 part peat, one part sand. This is what I’d did last year after I ran out of Promix. The sand was hydrophobic though, when I was potting some trees into 1 gal I would dunk the whole pot in a rain barrel until the air bubbles stopped and then put it on a rack to drain back in the barrel. I accidentally knocked one off and it spilled a lot of the media. That’s when I noticed the sand was dry as a popcorn fart. Even though I’d held it basically under water. I have a granular soil wetting agent called Rely II. I applied that to all of my containers so the sand would except water. It did remedy the situation.
Also I read that if your bark is not composted that it will draw the nitrogen out of the soil. I knew that could happen with wood chips and mulch that’s just ground up pallets. But I was under the assumption bark was different than the rest of the tree. I imagine that’s why he recommends using the slow release fert in the mix. Do y’all compost your bark or go straight from the bag? Or have you ever heard of that?

If you look at Dr. Whitcomb's works he talks about 2 mixes he uses to start trees. One is for 18s. It is 30/70 peat or fine pine bark. The other that you describe is for larger containers. I listened to one of his presentations a while back and during the Q&A he said the purpose of the sand was simply to add some weight to the mix. I'm presuming he meant that once trees get leaves and present a wind profile later in the year, the containers can blow over without some weight.

As for using me, the purpose of pine bark nuggets or wood chips in larger containers was simply to add chunkiness and reduce cost. Since I was using promix for my 18s, I just used it and added the nuggets to keep the cost down. I tried the sand it added nothing but weight to the container which I did not need in my setting. Wood does tie-up N as it decomposes, but that is not an issue for me with this application. Most of my wood chips are partially composted to fully composted now. I was using pinebark nuggets from lowes and they seemed to work just as well. I think since my trees are getting plenty of added N, any N tied up is not a real factor. A few years back, a neighbor had a tree taken down and I told the tree company they could dump the chips in my yard. I've had a couple taken down since, so I now have plenty at different stages of composting.

I just started mixing my own to save on cost. I'm using about 1/3 composted wood chips, 1/3 perlite, and 1/3 peat. Once you get to larger containers all of these mixes seem to work pretty well. The biggest issue with chestnuts is getting watering right as they don't like wet feet. It is the most problematic in 18s that are small and need constant checking. Once I get to 1 gal and larger, I find watering to make trees happy much easier.

Thanks,

Jack