Trees for compacted clay soil

I have an area of my yard that was used as a driveway several decades ago and the soil is still very compacted. There is now a lawn over this area but I would like to have some trees there. I have been trying to find the best tree for this soil condition. I welcome any suggestions. I have a few pines near this area so the new trees would have to mingle well with those.

I'm looking for these characteristics:
>ability to grow in compacted "red clay" soil
>medium sized 40-70ft
>somewhat resistant to storm damage
>non-invasive

I was considering Q.stellata or Q.marilandica, but I'm just not sure.

Search for "Compaction Tolerant Trees" Dr. Kim D. Coder Univ. GA
Lots of Oaks made her list but not the two you mention

Thanks claypa, I found that website. Q.falcata & N.sylvatica was on the list so I may consider those.

A lot of trees which are adapted to swamps are also adapted to compacted soil. So that includes a lot of cool stuff. Red maples. Nyssa. Bald cypress. Sycamore. River birch. Sweetbay. Also, a lot of the trees you'll see in cities in street plantings. Gingko. Honey locust. Lacebark elm. Zelkova. Ornamental cherries. Just some others I know will do well: Acer buergerianum, Acer campestre, Acer ginnala, Gymnocladus diocus, any Rhus, any willow, probably Amelanchier. I'm not familiar enough wiht the different oaks for use in compact soil to comment. I'm sure some can, but many cannot.

scott

Dr. Kim D. Coder (University of GA) may appreciate everyone knowing that he's a he. And not an insignificant gentleman either, given my memory of excellent presentations on many tree subjects at urban forestry conferences.

I don't disagree with the summations of tree choices listed above. Just consider: in "natural" or native situations, these trees are germinating from seed and growing into these sites at relatively slow speeds. In none of those occurrences are trees uprooted or transplanted from elsewhere, expected to reproduce all those lost roots, and then start growing happily.

In street tree concrete cutouts, generally the whole hole is loosened and then the poor new resident is installed. Tough life, often short, and not the performance one would expect in their yard. The fluctuations from totally droughty to totally saturated, often without adequate gaseous exchange and very low microbial activity, are not conducive to much ornamental reward.

The comparison to low-oxygen swamp environments is appropriate, but the same truth holds. Those swamp trees adapt as they germinate and grow -- they aren't thrown in as 2" caliper B&B with cut off root stubs. That's a really different condition.

I'm not escambiaguy, but I've played in his conditions in real life (and still do). Revegetating construction sites and rehabilitating abused soils happens all the time here at the parks, and I've had that "pleasure" often in the past on the farms.

Plow. Till. Subsoil. Auger. Do something (minimally or maximally) to break through the compacted surface to the depth that is less or not compacted. Leaving the compaction throughout and simply trying to get a few plants started in minor penetrations is not the recipe that I'd follow. Too long down the line, you may (will) find that you're not happy with the results. Without reasonable ability to penetrate roots to any depth, these plants will be necessarily exceptionally prone to windthrow.

One very common method that doesn't take a rocket scientist or a large budget is to use a drill with as big an auger bit that the tool will run. Drilling holes into compacted soils creates perforations for moisture penetration and air exchange that healthy soils (thus healthy plant growth) require. If you lived in a colder zone, it would also allow moisture-laden soils to freeze and thaw, thus further breaking up the compaction over time. In your warmer climate, moisture and air penetration will allow more soil flora/fauna activity which will benefit the soil structure and texture, especially if you fill the augered columns with some organic matter.

Some elbow grease is in order for good long term improvements. It is probably a daunting proposition; it is easy to make this recommendation from a distance. If doubtful, do both. Plant some of the suggested species (I'd say Robinia pseudoacacia, Juniperus virginiana, and male Maclura pomifera as multiseason never-say-die choices) and do some soil profile disturbance. Gradually, you'll have changes and you can assess for yourself what the results illustrate.

I agree with everything that VV just said. It is interesting that adaptation that allows many swamp dwellers to at least exist in concrete, streetside planting boxes has nothing to do with water needs, but everything to do with tolerance to low oxygen or gaseous exchange at the root level. Despite the soil in such sites being artificially loosened up at planting time, it invariably becomes compacted again quite quickly.

The vertical augering that VV mentioned, often referred to as vertical mulching, is a common technique to open up a soil to air, water, and, sometimes, nutrients. I think it is very effective up here, where, as VV mentioned, the freeze/thaw penetrates more frequently and deeper than it normally would. And, as far as I'm concerned, there ain't nothin' better for soil texture than plenty of freeze/thaw! And VV and I are in the freeze/thaw belt of America, ourselves and our soil oscillating back and forth in a normal winter tons more than folks to the south and even the north. The downside: fall planted stuff, not planted to absolute perfection, will be worked out of the soil and heaved unceremoniously out of the soil like, well, anything that is heaved out of another thing. And there it will be, your prized new coreopsis or heuchera, pitifully lying at your feet, only recognizable by way of its plastic tag that got heaved right along with it, when you finally get outside and walk the garden during those first warm days of March. (All the above does not apply, so far, to this winter, which has been one continuous string of days simulating those first warm days of March.) Nevertheless, I think vertical mulching would definitely be better than nothing anywhere, even here, despite lack of freeze/thaw.

Augers can be rented fairly cheaply from tool rental companies. Try to get one with as much horsepower as you can, and find an assistant with substance and mass if you can, because an auger with horsepower will tend to throw you into the next county when the bit hits roots or rocks otherwise. A 1" to 2" auger bit is generally right. You might compare the cost of the tool rental and an ER visit with that offered by a tree service or landscaping company, which might offer the service.

Scott

This message was edited Dec 29, 2006 9:24 AM

There's never a rocket scientist around when you need one.... my apologies to Dr. Coder.

I wonder how big a drill you're referring to. A nice half-inch D handled makita, or larger, like a rental demolition hammer? I guess any effort in this direction is an improvement.


edit- Boy, I gotta type and post faster in this crowd!!! : )

This message was edited Dec 29, 2006 9:38 AM

Alnus cordata is a good performer in heavily compacted soil. Other Alnus species like A. incana are also good, though tend to be fairly short-lived.

Resin

So would it be better to direct seed?

E-guy, How patient are you? :>}

E-Guy:

Better is such a loaded term...

As our Presque Isle Popsickle says:

Direct seeding will mimic nature more. You will have sporadic germination, and probably outstanding mortality rates due to drought, predation, disease, and fire. You'll have to accept the final arrangement of individuals based simply on chance. However, you will have invested the absolute minimum effort.

Better (to me) is to prep the ground, and try to rejuvenate its former qualities before it was so rudely roaded.

Claypa:

This ain't brain surgery either (but seems to be scads of them loitering about; business is good in KY).

I'd start with what you might have on hand. The Makita sounds good. I drilled 10,000 holes in fall 1985 planting crocuses at Gainsborough Farm with this size implement, running off a portable generator and a hundred feet of cord. You learn to let go when the bit hooks a tree root, if you value your appendages.

You can use any size bit you want. Bigger gives a better (there's that word again) effect, and you have to make less holes. Bigger holes require more power, so the Makita might not have the horses. Dry soil is harder to auger into than moist. One could drill a bunch of pilot holes with a smaller drill (good chore for youngsters, with the appropriate OSHA warnings) and then upgrade to the next size. A posthole auger on the back of a tractor could do a lot of damage in relatively short order.

Innumerable solutions; lots of time.

Yep, forgot, but meant to mention that if a two handled auger can throw you bodily into your neighbor's yard, a hand drill can wind your arm up like a a toy airplane propellor! I have a two-cycled 2.5 HP Echo hand drill which isn't quite strong enough to consistently auger 2" wide x 18" deep holes, but it will spin my arm six times before I can release the trigger.

Scott

I always wondered where Plastic Man went to. :>}

Now I got that 80's song stuck in my head "you spin me right round" (something like that) LOL

I have enjoyed the swedish aspen. I have not seen many runners in the clay unless it hits an obstruction. Short lived (over 20 years) but it grows rapidly to 40ft and stops (less than 6 years). I like these trees.

That's a neat tree Soferdig.....Rewarding in that you can see its whole life span in yours (if you are lucky)...perfect tree for me...we could die together.

If only Salicaceae was here. That's one of his favorite trees, and he'd be overjoyed with someone of like mind.

Leftwood I feel you are being facietious. I truely love the spring summer fall and winter aspects of these unique and hearty trees. Here is winter.

Well, truely, the answer is yes and no. It really is one of Salicaceae's favorites, but as for me, I could take it or leave it.

And Salicaceae had probably the largest collection of "poplars" on the continent, before he moved to Florida this fall. So I conceed, maybe I am missing something.

Early to bloom in spring with a Gold/Green emergence. Some Cinnamon essence early. Very columnar. OK I have sold it enough so I quit. Another good clay tree I enjoy is my Pagoda Dogwood, Cornus Alterfolia.