Circling roots on conifers

Two years ago I planted 4 longleaf pines in my front yard. These things are well known for their massive taproots, so the most popular thing to do for non-plantation planting is to buy them in containers. Well, on a popular website that specializes in longleaf pines it said that after pot grown trees get about 20ft tall they will fall over. I have read this same thing about Scots pines. They are growing beautifully so what should I do now? Should I try to dig them up and spread the roots a little? I know how finicky pines are about having their roots disturbed. I don't want to watch my trees grow for 15 years to have them fall over. What if I drove a sharp shovel in the ground on one side, wouldn't that sever any circling roots?

They are growing beautifully now, as you already stated.
WHAT IS YOUR QUESTION?

Interesting question. I've also read container grown pines can topple. I have yet to experience this so I'd be interested in knowing if there is any validity to this "toppling" myself although I don't think a sharp shovel is the answer.

Very difficult if not impossible to deal with. The coil of roots that develops at the bottom of the pot acts as a hinge allowing easy rotation, which is why they fall over after a few years. Unfortunately, all of the new roots grown subsequent to planting out grow from the end of the coil; cutting the coil means you are cutting off the entire root system and leaving the tree with nothing. And as you say, they don't like disturbance - they don't re-grow new roots easily if at all from stubs of cut roots.

Nice diagram, Resin.

The key is: examine the root system of ANY container grown plant before installing, not just conifers. If there is a dense mat of roots at the container surface, there's a good chance that there are problems within the container media. Loosen, loosen, loosen; spread, spread, spread; sever those that are circling or looping lest they negatively surprise you in the future.

Many other types of plants can fail suddenly, years after installation, due to complications of faulty/lousy roots which were created by the plant production system.

Historically, graft incompatibilities led to quite fine clonal red maples and oaks just snapping at the graft point. Deciduous plants are prone to blow down or sudden breaking at or near the crown, due to girdling or encircling roots which are increasing in diameter just like the trunk/basal flare. To visualize this: imagine putting on a scarf when you are six years old, which you are never allowed to take off. In fact, you are going to tighten it gradually each year as you get older. Hmmm. Getting a little snug, eh? This is the noose that terminates the life of many trees as they age (again, maples are especially prone to this, among other species). The encircling or girdling roots increase in diameter and meet the increasing trunk/basal flare diameter and the plant chokes itself, reduces/weakens growth until environmental conditions (usually a strong wind) breaks it off or blows it over.

I've never seen the example with the pine described above, but I've seen plenty of similarly insidious situations. Around the upper South and Midwest, many conifers are grown for cut Christmas trees. Typical nursery techniques to "line out" the young conifer seedlings involves using a row-type setter that one also might use for setting out vegetable starts or tobacco plants in a field. The speed at which this setter is moving creates a little bit of a "drag" as the plant is placed into the ground, which pulls the stem of the plant forward and leaves the roots tailing behind. Imagine the shape of the letter J, and you get the idea of where the roots are positioned relative to the stem of the young seedling in the field row.

Years later, the tree is ready for harvest as the intended Christmas tree. It has a full complement of roots that have grown from the seedling, but they are unfortunately mostly all growing in one direction or in a small percentage of the full circumference that one would expect normally. As a cut tree, this root situation DOES NOT MATTER. As a balled-and-burlapped plant meant to be transplanted...buyer beware. Way too many uninitiated holiday shoppers, beaming with the glow of the season, see the incredible bargains presented by the opportunity to purchase one of these trees. These are mostly only offered by growers unable to sell all their trees as cut items, which are far easier to harvest and offer the most efficiencies/profits. These B&B trees are defective in that they may have roots growing only in one direction (J-rooted) which take up about a quarter of the soil volume in the rootball.

These trees grew fine in the field, because their roots were not disturbed, though poorly distributed. They fail after transplanting because very few roots go with the ball of soil, usually insufficient to support the tree for very long in its new planting site. Additionally, since the circumferential distribution of the roots are poor, the poor tree is subject to windthrow/blowdown pretty much forever since it is only root-supported in one direction (imagine a flagpole just stuck in the ground with no concrete footer, only a string holding it up from one stake).

I worked for a large estate for a few years where the owner thought he was getting the best deals and planted literally thousands of Pinus strobus that originated this way, usually starting as 6-8 foot B&B plants. Despite legions of horticultural staff providing intensive support, these trees would, one by one, repeatedly fail. Some had strived and reached heights of twenty feet before snapping or blowing over.

Finally, the chief horticulturist had some of us perform autopsies on the failed plants. The heat was on him to explain what was going on. With the washed-off root systems there for everyone to see what was occurring, this practice of plant purchase pretty much ceased.

I still visit this property from time to time. The estate is much more elegant with fewer and smaller masses of evergreens at its borders, kind of creating windows to view into the fields instead of a solid impenetrable wall. There are still trees failing (now fifteen years later) but I see no new additions of like kind.

Old dogs can learn new tricks.

It doesn't sound very encouraging. I'll let them grow long enough to get some good pine needle mulch from them and then get rid of them. I don't need them to become a safety hazard someday. Seems the most popular thing now is to buy those "plugs" which are grown in copper lined containers. Somehow the copper prunes the roots.

Resin thanks for the great diagram and VV you have a real talent for clarifying more complicated topics for knot heads like myself. kt

I don't remember seeing any large circling roots. Is it possible that these were plugs that had the taproot pruned before they were potted up into larger containers? If I am remembering correctly, the root ball was more fibrous looking.

I was concerned about the container grown trees so I bought some seed. I put them in the fridge wrapped in a moist towel and after three days they started to swell like they were going to germinate. I have read that pinus palustris seed germinates in the fall, so I decided to go ahead and plant them directly in the ground because of the taproot issue. Is there anything I need to look out for, like certain critters? I have never grown pines from seed.

Escambiaguy, when I planted my Forest Pansy I didn't see any circling roots either. It looked nice and loose and fibrous, as you describe. I just moved it - 2 months later - and it had several nice white large (for the size of the small tree) circling roots that it had grown. Weird. I got some suggestions about what I did wrong on the thread I posted about it. I don't know if any responses might apply to your planting. (Sorry, don't have time to link to the thread - posted a day or two ago).

I have read that longleaf pine naturally has a taproot 8-12ft long. When they are grown in containers this taproot is usually pruned off or allowed to circle. I got to thinking that big taproot is there for a reason. I guess some trees just aren't meant to be grown in containers. I'm sure hickories would have the same problem.