How to handle roots on pitch pine seedlings

Lazylightningny

Masterpiece
Messages
2,257
Reaction score
2,105
Location
Downstate New York, Zone 6b
USDA Zone
6b
I have several pitch pines that are only a few years old. They are in the ground and I moved them this spring to a better location. When I lifted them I noticed that they have long tap roots and not much in the way of fine feeder roots. How, and at what point should I remove the tap roots?
 

Wires_Guy_wires

Imperial Masterpiece
Messages
6,411
Reaction score
10,637
Location
Netherlands
How? By snipping them off. Or turn the taproot into a trunk. What else is a trunk other than a long taproot above soil level? If all the feeder roots are below it, it doesn't make a difference to the tree. Roots can bark up when they're exposed to air and light.

What point? When there's fine feeder roots, enough of them to support the tree.

This is a known field growing issue, and why people avoid collecting trees from sandy locations.
When I sow pines nowadays, I keep them in very shallow containers to prevent a taproot from forming. And in organic material as opposed to coarser inorganic, the high water content really helps to prevent taproots from forming because there's a dead zone on the bottom of the container. That practice means that when I put them in the soil, either of these two situations happens:
- One root takes over and becomes a taproot.
- All roots produce feeder roots and no taproot ever forms.

The longer you wait and the sandier your soil is, the bigger the chance of the first situation occurring. In damp forest floors, this rarely happens.

I dug 30 red pines this spring (sown in shallow pots in 2018 or 2017), and they all had a serious tap root digging half a foot into the ground. I think I've read it somewhere but I'm not sure, my own experience would say that it's a good idea: Dig them up every single year for the first couple of years and keep the roots maintained. After some 4 years, you could expect that they'll stop trying to make that tap root.
I don't know if girdling could work, or if they might bridge it.

I'm doing the first couple of years in a pot now. Ground growing is faster, but it also means that I can have 30 nice looking pines out of which just 10 survive after a serious root cut. I'd rather spend that extra year, keep 10 nice ones and sell the other 20.

One technique that occurs naturally in pot grown spuce, is that the tap root coils up around the edge of the pot. Eventually it will start sending out finer feeder roots. This could take years, decades even. It's a possibility to keep in mind; just bend the thing upwards and hope for the best.

Grafting seedlings (root grafting) into the base is another possibility. But I've never done that.
 

Lazylightningny

Masterpiece
Messages
2,257
Reaction score
2,105
Location
Downstate New York, Zone 6b
USDA Zone
6b
Dig them up every single year for the first couple of years and keep the roots maintained.
I assume you're advocating removing the tap root in stages and not all at once? Perhaps cut in half initially? That would seem prudent. They are all around finger thickness at this point.
 

Wires_Guy_wires

Imperial Masterpiece
Messages
6,411
Reaction score
10,637
Location
Netherlands
I'm a terrible advocate, I do them at once. But that's a very Spartan approach.
The reason being is that taproots tend to enforce tap-root growth. If one new root forms from the existing (but cut) taproot, then it's likely to become a taproot itself. This is a physiological thing in all plants, to keep the tree anchored well. At least, if the soil conditions don't change.

When digging seedlings up every year, you can probably cut the taproot entirely in the first and second year without any issues. They're usually strong enough to get through that procedure unharmed.

If your tap roots are around a finger in thickness, I'd say the 'without issues' part is in the past and it's risky now. You could do it in stages, maybe make use of a wooden board or tile to prevent new taproots from forming and encourage adventitious feeder roots.
 

Leo in N E Illinois

The Professor
Messages
11,337
Reaction score
23,254
Location
on the IL-WI border, a mile from ''da Lake''
USDA Zone
5b
As soon as possible, I would remove the entire taproot. No half measures. This will stall the growth of the top of the tree, until it develops a better, radial set of feeder roots. The sooner this is done, the better the chances of survival. Young seedlings bounce back from tap root removal quite nicely. The older the tree, the greater the mortality rate when removing the tap root.
 

Lazylightningny

Masterpiece
Messages
2,257
Reaction score
2,105
Location
Downstate New York, Zone 6b
USDA Zone
6b
As soon as possible, I would remove the entire taproot. No half measures. This will stall the growth of the top of the tree, until it develops a better, radial set of feeder roots. The sooner this is done, the better the chances of survival. Young seedlings bounce back from tap root removal quite nicely. The older the tree, the greater the mortality rate when removing the tap root.
Should I put them back in the ground, or into a pot?
 

DirkvanDreven

Shohin
Messages
463
Reaction score
1,055
Location
Wageningen, The Netherlands
USDA Zone
8b
I'm a terrible advocate, I do them at once. But that's a very Spartan approach.
The reason being is that taproots tend to enforce tap-root growth. If one new root forms from the existing (but cut) taproot, then it's likely to become a taproot itself. This is a physiological thing in all plants, to keep the tree anchored well. At least, if the soil conditions don't change.

When digging seedlings up every year, you can probably cut the taproot entirely in the first and second year without any issues. They're usually strong enough to get through that procedure unharmed.

If your tap roots are around a finger in thickness, I'd say the 'without issues' part is in the past and it's risky now. You could do it in stages, maybe make use of a wooden board or tile to prevent new taproots from forming and encourage adventitious feeder roots.
Pictures please?
 

Lazylightningny

Masterpiece
Messages
2,257
Reaction score
2,105
Location
Downstate New York, Zone 6b
USDA Zone
6b
I have 4, all similar to this one. All are in the ground. I put some wire on them down low the first year to get some movement into them. Some of the base is buried below the soil for stability. They will eventually all be shohin, so I'm not so concerned about movement up higher. They all have two spindly branches down low, which I'm hoping will eventually sprout more buds and be usable. I'm fertilizing weekly.

Should I be doing anything to these other than letting them grow? Any pruning needed yet? My main goal is to get as much foliage down low as I can.

20200429_113044.jpg
 

Leo in N E Illinois

The Professor
Messages
11,337
Reaction score
23,254
Location
on the IL-WI border, a mile from ''da Lake''
USDA Zone
5b
From 8 inches (10 cm) and higher, could remove all the needles up to 3/4 the way to the top of the escape sacrifice. That is if you want to keep with the Shohin plan. That would prevent the lower branches from getting shaded. Though it doesn't look like that is an issue yet. I might also reduce the sacrifice to a single shoot.
 

Lazylightningny

Masterpiece
Messages
2,257
Reaction score
2,105
Location
Downstate New York, Zone 6b
USDA Zone
6b
I might also reduce the sacrifice to a single shoot.
I was wondering about this. I was torn between keeping it (more foliage for extra growth) or removing it (energy wasted on unnecessary branches). Since I have 4, perhaps I could experiment and remove the second apex on 2 of them?
 

Leo in N E Illinois

The Professor
Messages
11,337
Reaction score
23,254
Location
on the IL-WI border, a mile from ''da Lake''
USDA Zone
5b
Yes, more foliage = more growth, more increase in trunk diameter. I was thinking about the tree falling over, because it was looking top heavy. Also removing that one branch now might help trigger a little more activity in the first few small branches in the Shohin zone. To removing needles, and trimming sacrifice to a single main branch would be more to stimulate low growth. Without slowing the development of trunk caliper by too much.
 

Lazylightningny

Masterpiece
Messages
2,257
Reaction score
2,105
Location
Downstate New York, Zone 6b
USDA Zone
6b
Yes, more foliage = more growth, more increase in trunk diameter. I was thinking about the tree falling over, because it was looking top heavy. Also removing that one branch now might help trigger a little more activity in the first few small branches in the Shohin zone. To removing needles, and trimming sacrifice to a single main branch would be more to stimulate low growth. Without slowing the development of trunk caliper by too much.
Thank you. I read something similar writted by Bill Valavanis. If memory serves, he has one main sacrifice branch, and trims all extraneous branches off the sacrifice branch, like a beanpole. The beanpole grows long, and thickens the base. I tried it on a Japanese crab and got some tremendous growth. Not that pines are the same as crabapples, but auxin is auxin, so the principle should be the same.
 
Top Bottom