because of bad clay soil below ...

the link ought to cover it ... advise if you cant find it ... i will gladly explain such if you wish

ken

Here is a link that might be useful: link

Personally, I have no trouble with the look, but it makes me nervous. I would think it would make the tree more vulnerable to toppling over in the wind during it's early years. (Less anchoring the roots) and would require more watering in the first couple years. I alwats hear people harp on the "never amend the soil in the planting hole" point, using the argument that the roots won't leave the cushy amended soil. Wouldn't there be the same risk with an amended hill? I can imagine roots spreading outwards until they reach air, then stopping.

This post was edited by edlincoln on Thu, Dec 11, 14 at 21:57

Trees can more quickly adapt to having their roots over exposed than buried. Has to do with oxygen to the roots.

In my wild it seems they can deal with erosion better than being flooded amd left with sedament.

"Trees can more quickly adapt to having their roots over exposed than buried."

So true...

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...and a bit closer.

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tj

man junkie... you really missed putting the root flare at ground level ....

what??? ... thats not your yard????... lol

ken

Just for grins, here I am standing between the roots of a Moreton Bay Fig on the island of Kauai in Hawaii. Allerton Garden.
Mike

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Roots are slow to leave amended planting holes when the amending causes problems with water levels - too much or too little - inside the planting hole, resulting in stunting of the recently planted specimen, poor root growth.

Roots do not linger in amended planting holes because the amending makes them better than the surrounding soil - it is unfortunate that this false concept has become dominant.

Poor or slow rooting out also occurs when newly planted specimens are in poor general condition - including root-bound - at time of planting.

I still think this ties into the over-enthusiasm some people have for "raised beds". I think for some people it is an aesthetic preference. It gives people a sense of control and differentiates the things people plant from the weeds.

It's also an easy way to get rid of grass around the tree, and maybe create an improved bed you can plant a ring of flowers in.

Doesn't "air pruning" affect how roots form? I imagine a tree planted on a little hill over hard clay soil would experience a similar effect. I also suspect this strategy could cause a lot of problems for newly planted trees during a draught, or in a very windy area.

The air pruning that occurs is that the roots above grade follow the slope of the above grade root ball until they come to the normal grade.

tj

Edlincoln - "Personally, I have no trouble with the look, but it makes me nervous. I would think it would make the tree more vulnerable to toppling over in the wind during it's early years. (Less anchoring the roots) and would require more watering in the first couple years"

Yes, you have to stake the plant well and be extra vigilant in dry weather. But the pay off is you can relax in heavy rains as there's no way your plant is going to get waterlogged. The 'volcano' does sink gradually and in a few years it would be more a low hump. I have plants that now look almost on ground level and their roots are still completey buried. Clay seems to just resume it's original level if piled up.

"The 'volcano' does sink gradually and in a few years it would be more a low hump. I have plants that now look almost on ground level and their roots are still completey buried."

Yep in 2008 I planted my Fagus 'Rotundifolia' about 8-9" high and now it is about 3-4" higher than the surrounding soil.

I don't disagree w/bboy's post but I doubt anyone has proven beyond a shadow of a doubt that certain plants, faced with much improved soil dug out of hardpan, don't simply fill in the improved soil because it is, in fact, superior to the surrounding hardpan. In any case, the distinction is academic and for whatever reason, you shouldn't do it. OTOH, I am convinced the fact that I rototilled large 25'X40' or larger areas with permatill has facilitated the faster establishment of certain soil-quality-sensitive plants in those areas. I'm not the only one with this experience, either. I could see with my own eyes during the floods of Hurricane Irene that the soil in those areas was drying and re-aerating faster, and that probably kept more rhododendrons from drowning.

This post was edited by davidrt28 on Sat, Dec 13, 14 at 15:35

Thanks for all the discussion. I started this post but have been so busy this time of year!

I don't buy the idea that the tree mound is done to keep it above clay. Clay is quite rare and I know there isn't much in my area, yet young trees all over the place are on these "stupid high" mounds. I can understand the idea of the mounds settling down over the years.

So what I'm learning is that trees are planted in mounds because the risk of water logging the roots is serious enough that mounding is insurance against that. AND, over the years the mound goes away for the most part. Is that right?

I'm still not convinced that it isn't being done because the landscaper thinks it looks nice. I guess I'll only know if I find them in the act of planting a tree.

On the idea of the tree settling down over time, here's a counter point to that (and I could show 50 more photos just like it!):

How come the raised mounded tree does not dry out faster during summer droughts? Bad for newly planted trees.

I've seen many rows of raised Arborvitae have dead trees, not easy to kill Arborvitae.

Customers must like the raised look, it looks "professional". Also makes the tree/shrub look taller.

Might be easier and quicker for the landscaper/city worker also, don't have to break up the dirt much... this might be the real reason you see some of these "volcanoes" so steep. It's easier.

"Easier"... maybe that's it. A lot of the trees I'm talking about are on commercial properties. Maybe there's less attention paid to it as the property owners probably don't know any better.

High planting is done to avoid drainage problems.(period)
that last pic is the goofiest planting I've seen
clay rare ??? I bet you dig down 2 ft. you'll hit clay,,,or sooner
ron

Ron - I suppose maybe you're right about clay 2' down. I'm not well informed on conifer care (but am learning), so I don't know what is 2' deep soil-wise. For lawncare, however, I can tell you that most people seem to think they have a clay rich soil, and probably less than 1% actually do. Maybe that doesn't hold for deeper depths like you say.

I planted this Sequoiadendron level with the ground in 1978. No mound or volcano. It's on a gentle hill in light, thin soil. It made it's own volcano.
Mike
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WWo5 If that's what it looks like after 35 years I can only imagine what it will look like in 1035 years!

Large amended beds are different than individual planting holes because the edge of the prepared area is farther away - except for stock planted near the edge of the bed. But it still remains true with a large bed that the main thing the roots are responding to is the aeration produced by the loosening of the soil during the working in of amendments - and not the presence of the amendments themselves. Which (except for mineral materials like sand) decompose and filter away, to leave long-term plantings sitting in the original soil just the same as with small holes. Making amended beds and planting holes for woody and other perennial plants - anything that is going to be in place longer than the amending holds up - pointless.

The folly of top reduction at planting time, amending of planting hole back-fill and other cherished but wrong gardening and landscaping operations notions was being exposed by organized, serious studies using controls and systematic data collection by the late 1960s. See the publications of Carl E. Whitcomb, the International Society of Arboriculture and other sources reporting research findings. Some of this material is online, otherwise the library of a college with a horticulture program is a good place to look for books and periodicals that cover this kind of thing.

This post was edited by bboy on Thu, Dec 25, 14 at 16:41

"Which (except for mineral materials like sand)"
"Making amended...pointless."

Well, exactly. It isn't pointless if you _are_ using something permanent, like Permatill, Turface, sand (in cases where appropriate), etc. In face a golf course can just be considered a "super duper amended with sand" artificial soil for the incredibly intensive cultivation of a plant (grass!) that will be in place "as long as" the amending hold up, to paraphrase your language.