Taproots 101

[penumbra]

Taproot is a word that is not really well understood by many people. I often read a post where someone describes the removal or cutting of taproots, when what they are actually removing is large woody lateral roots.
A taproot develops from the radicle of a seed of a dicot. This is everything from a carrot, which uses a taproot for storage of carbohydrates, to an oak, which like many trees uses the taproot to anchor the tree. The taproot grows straight down and produces lateral roots which produce feeder roots. With some plants, as in nut trees, the taproot persists for the life of the tree. With other plants, say a dogwood, the taproot is replaced by lateral roots with feeder roots.
When you are removing large roots when digging wild plants or transplanting well established plants, you are almost always removing large woody lateral roots. If there is a large central root going straight down, it is a taproot. This root does not feed the plant, it only anchors the plant and produces lateral roots. In bonsai, the taproot is useless although the uppermost part of the taproot may have strong lateral roots. A plant only has one taproot although the taproot can divide if damaged or strikes an insurmountable barrier.

 

[Frozentreehugger]

Interesting info did not know . The taproot does not feed the plant other than produce laterals . Was if the impression. That’s it’s search down . Was critical for water access to help survive . Drought and the cold of dormancy . But we get stunted trees growing in a soil pocket . In nature and when collected often can’t tell what wax the tap root . Not always but they exist . I have heard some believe nutrients are stored in the Tao root of some species during dormancy . And released when re growth in spring . But bonsai with no tap root do it every year so always had my doubts . Thanks for the info

 

[penumbra]

Interesting info did not know . The taproot does not feed the plant other than produce laterals . Was if the impression. That’s it’s search down . Was critical for water access to help survive . Drought and the cold of dormancy . But we get stunted trees growing in a soil pocket . In nature and when collected often can’t tell what wax the tap root . Not always but they exist . I have heard some believe nutrients are stored in the Tao root of some species during dormancy . And released when re growth in spring . But bonsai with no tap root do it every year so always had my doubts . Thanks for the info

It does store energy, just like a large carrot. But all the large woody roots do, like potatoes.

 

[penumbra]

I just wanted to bring this back up to the top because it seems almost everybody talks about cutting taproots when the repot. I would like to add that most trees do not have taproots beyond the seedling stage.

 

[Cajunrider]

I just wanted to bring this back up to the top because it seems almost everybody talks about cutting taproots when the repot. I would like to add that most trees do not have taproots beyond the seedling stage.

My understanding of tap root is as you described.

 

[Lutonian]

https://www.trees.org.uk/Trees.org.uk/files/61/6181f2b7-e35d-4075-832f-5e230d16aa9e.pdf

3 Types of Tree Root Systems - A Plus Tree

Understanding the 3 types of root systems trees have can help you take care of your tree or select the best tree for your property!

aplustree.com

Trees and Roots

Woodland for sale throughout the UK, including woods for sale in England, Scotland, Wales and Northern Ireland. Advice on buying a wood, as well woodland activities, flora and fauna, conservation and other woodlandy topics.

www.woodlands.co.uk

5 Tree Root Myths Explained

There are many preconceived notions about tree root systems. Tree roots are sensitive but tougher than expected. They just need appropriate care.

www.treehugger.com

 

[namnhi]

My understanding of tap root is as you described.

Same here

 

[August44]

I read all of these but not sure I agree with this one. Goes against all that we are taught and what we do it seems. Thoughts appreciated.

5 Tree Root Myths Explained

There are many preconceived notions about tree root systems. Tree roots are sensitive but tougher than expected. They just need appropriate care.

www.treehugger.com

 

[Leo in N E Illinois]

I read all of these but not sure I agree with this one. Goes against all that we are taught and what we do it seems. Thoughts appreciated.

5 Tree Root Myths Explained

There are many preconceived notions about tree root systems. Tree roots are sensitive but tougher than expected. They just need appropriate care.

www.treehugger.com

I read through, said "what?" then re-read, and mostly said, well, maybe okay. The 38 times the trunk diameter had me scratching my head at first. But it is true that tree roots in nature tend to grow much further out from the trunk than we conventionally think, and key is the roots in nature are almost never in a nice radial arrangement. Usually a root system in the wild is a random arrangement often only one or two very long major roots and then various other smaller roots in other directions. So I'll give them them the 38:1 trunk to root spread ratio.

The bit about pruning roots at the end, well makes sense if you are planting a tree you want to take off growing as rapidly as possible in a new hole in the ground, if you just untangle roots rather than pruning them. Obviously they never did bonsai, and they don't know much about container raised trees.

All in all, the "facts or factoids" are more or less correct. Just a bit glib.

 

[Wires_Guy_wires]

I just wanted to bring this back up to the top because it seems almost everybody talks about cutting taproots when the repot. I would like to add that most trees do not have taproots beyond the seedling stage.

How would you call a huge root that acts as an extension of the trunk? Not trying to poor oil on the discussion, I'd just like to know if there's a term we can use instead.

 

[nuttiest]

Taproots are a wonder of nature and are designed to pump water to feeder roots. Hundreds of gallons per day on a large tree by osmotic pressure to dry upper roots, and then to leaves to evaporate. Way more transpiration even adjusted for size, than a perfectly watered bonsai.

 

[August44]

I read through, said "what?" then re-read, and mostly said, well, maybe okay. The 38 times the trunk diameter had me scratching my head at first. But it is true that tree roots in nature tend to grow much further out from the trunk than we conventionally think, and key is the roots in nature are almost never in a nice radial arrangement. Usually a root system in the wild is a random arrangement often only one or two very long major roots and then various other smaller roots in other directions. So I'll give them them the 38:1 trunk to root spread ratio.

The bit about pruning roots at the end, well makes sense if you are planting a tree you want to take off growing as rapidly as possible in a new hole in the ground, if you just untangle roots rather than pruning them. Obviously they never did bonsai, and they don't know much about container raised trees.

All in all, the "facts or factoids" are more or less correct. Just a bit glib.

Sorry I did not mention that it was the bit about not pruning off root tips that bothered me. A lot of folks just cut the root ball in half or thirds when it comes out of the nursey pot and they do just fine. One really has to watch what they read AND believe I guess.

 

[penumbra]

How would you call a huge root that acts as an extension of the trunk? Not trying to poor oil on the discussion, I'd just like to know if there's a term we can use instead.

In some cases it might be a tap root that has made a detour. Most probably though, it is a large lateral root. A third but less plausible, though altogether possible, is that it may be an extension of the trunk.

 

[Frozentreehugger]

Have to admit I have lost track of the point or focus of this discussion. A wild collected tree . Is often collectable because it grows in a pocket or somewhat restricted root zone . Such trees share similarity with nursery pot grown trees . Often have a primary root that lengthens . And ultimately grows around the confines of its restricted area . Branching out as it goes into feeder roots . For our purpose as bonsai . Does it matter if it is the original tap root or a lateral root that toke over growth . Or a second root extension from the trunk . Is there a significant difference in the roots make up if it is the original tap root . Some trees like Oaks and walnuts . Seem to have fairly dominant tap or single large anchoring roots . Others like hemlock and spruce have spreading shallow root systems . Is there a importance we need to consider to a tap root

 

[ShadyStump]

I haven't gotten to reading all the posted articles yet, but from what I've seen so far they're really targeted to an audience in the vein of grade school or middle school teachers looking for tidbits to share with the class on Arbor Day.
True... ish, but a gross over generalization, mostly applicable to temperate climate deciduous as that's what most people think of when you say the word, "tree," and somewhat discounting the diversity of trees, and certainly not fully applicable to bonsai practices beyond initial collection and/or repotting.

However, they do suffice to make @penumbra's original point: let's get our vocabulary straight. It confuses people, and communication is already a trick enough endeavor.

 

[Deep Sea Diver]

Good discussion on anatomy. Here’s a link to a more scholarly approach, yet pretty well written. Perhaps Roots 102?

https://www.trees.org.uk/Trees.org.uk/files/61/6181f2b7-e35d-4075-832f-5e230d16aa9e.pdf

cheers
DSD sends

 

[penumbra]

However, they do suffice to make @penumbra's original point: let's get our vocabulary straight. It confuses people, and communication is already a trick enough endeavor.

Honestly, its just something of a pet peeve of mine. Misuse of words is common to most of us, misspelling even more so. Believe me, I am one of the worst spellers, but I seldom print them unless it is an error of sloppy finger work because I check my spelling. Misuse of words is glaring to me and as a writer or a reader it interrupts my train of thought.

Good discussion on anatomy. Here’s a link to a more scholarly approach, yet pretty well written. Perhaps Roots 102?

https://www.trees.org.uk/Trees.org.uk/files/61/6181f2b7-e35d-4075-832f-5e230d16aa9e.pdf

cheers
DSD sends

This is a fabulous link.

 

[Cajunrider]

When I collect trees nowadays, I dig the perimeter straight down and find all the side roots. Then I pick appropriate gaps between the side roots to angle in to sever the tap roots. Until I am certain that I have severed the tap root, I don’t push very hard on the trunk. I have accidentally pushed too hard before and cracked the tap root all the way up into the trunk. That is very tough to heal properly. Half of the trees I have lost in collection so far was from this very mistake.

When we make mistake with a side root the mistake ends where the wood grain enter the tap root. When we make mistake with the tap root, the wood grain goes right up the trunk core.

 

[Frozentreehugger]

There is some very good research material in this thread . Some of this has long been of interest to me . Mainly for cold hardiness . USDA zone 4 here . Keep in mind most of it states roots stay shallow mostly no deeper than 2 M . This is still 6 feet . A tree here in nature. When young is often buried in snow during the coldest part of winter . When more mature the tap root or other deep roots penetrate bellow the frost line . And can access un frozen water in dormancy . This is the primary reason for my belief that cold hardy trees in pots . Have no problem surviving there roots being frozen . After all there Shallow roots freeze in nature . But there must be no demand for moisture on the tree . I believe the largest culprit is wind . It’s desiccation effects are deadly . For a tree without root access to non frozen water that the tap root and or others supply in nature . As a tree expert said once . . At the end of the day trees don’t sense temperature . Just moisture needs . Winter is just a long dry season. The taproot is a mechanism to source consistent water in this dry season