Comments for Taking Place

Comment on Question: Inorganic Mulch and Girdling Roots by Deb

Deb — Wed, 03 Dec 2008 14:22:01 +0000

I think that inorganic mulches may work better. If they’re covering up the trunk flare and holding moisture against the bark, though, then it seems plausible that an inorganic mulch would promote those problems.

Particle size may make a difference. Pea stone drains better stone dust; small boulders drain better than pea stone.

Several years back Martha Schwartz did a project in the Southwestern US. She planted a grid of trees in the flat plane of a courtyard, and used a mulch of small boulders around each tree. It had a very graphic, Flintstoney look — very striking — and I’ve always wondered how successful that mulch was. Does it keep the roots cool? Does stored heat radiate up and out from it, and if so, what effect does the heat have on evapo-transpiration?

Comment on Name That Tree by Deb

Deb — Wed, 03 Dec 2008 13:42:24 +0000

Metasequoia glyptostroboides? Or Taxodium distichum?

Comment on Question: Sedum Performance by Deb

Deb — Tue, 02 Dec 2008 20:46:21 +0000

Good questions. What about juniper species (especially rug and creeping junipers), dune grasses, other grasses, and various herbaceous perennials that deal well with poor growing media and/or shallow soil depths? Sedums are very neat-looking, and make a nice tapestry, but it seems as if plenty of other plants may be as useful.

Comment on Mixing soil 2 by Toby

Toby — Tue, 02 Dec 2008 14:01:05 +0000

Soil stockpiling should also appear in the Site Preparation spec.

Comment on More Leaves by Mianne

Mianne — Tue, 02 Dec 2008 02:27:40 +0000

Ohhh, just lovely.

Comment on Mixing soil 2 by Toby

Toby — Tue, 02 Dec 2008 02:27:13 +0000

I know of soil specs that deal with this (pile no higher than x feet; if left for more than y days turn over) but I don’t know the specifics. I believe compaction is an issue as well.

There’s also the fact that the soil structure and biota arose from the processes in a particular setting (forest floor, corn field) and may change and/or not be suited to a different setting or use (lawn, sunny perennial bed), so even a “perfectly good” soil may need modification before reuse.

Nonetheless it still seems wise to keep soil on site wherever feasible; good soil is so biodiverse that it’s likely to include at least a few organisms that will survive the stockpile and go on to lead happy productive lives.

Better yet, preserve existing soil structure wherever possible by minimizing the disturbed area . . .

Comment on Question: Mixing Soil by Deb

Deb — Mon, 01 Dec 2008 23:09:30 +0000

I would think that a front-end loader or even Bobcat (on very small jobs) is likely to do the work.

Nina Bassuk from Cornell’s Urban Tree Institute showed a great video on the mixing of structural soil several years ago, when she was consulting with our firm on planting soils to be used in Boston’s Central Artery project. Structural soil combines angular crushed stone, clay loam, and hydrogel to produce a medium that allows root growth even through the intense compaction required under city sidewalks. Nina’s video lasted only a few minutes, but showed, at double-speed, how the machine operator blends buckets of loam, stone, and hydrogel.

The assurance of a consistent blend — well, that might depend on how thorough the machine operator is, or how closely the LA keeps an eye on the operation (an expensive proposition), and on some post-mixing soil testing.

Comment on Question: Sedum Performance by Toby

Toby — Mon, 01 Dec 2008 22:31:14 +0000

I understand the benefits of rooftop plants; my question has more to do with the level of benefit obtained through the use of plants that are selected for their low rate of transpiration, the next questions being whether in fact anybody has quantified the benefits of a living roof compared to various kinds of non-living roofs. How much more water is transpired by Sedum than by a soggy layer of organic soil? How much less heat is absorbed by a Sedum-covered roof than by a roof covered in white pea stone? Is there a light-covered spongy material that is resistant to wind erosion that would offer advantages similar to Sedum with lower costs and greater predicatability?

It’s not that I dislike Sedum or vegetated roofs, treehugger that I am; I just want to know as much as I can about alternatives and trade-offs.

Comment on Question: Sedum Performance by Deb

Deb — Mon, 01 Dec 2008 22:03:41 +0000

Does anyone know about the implications of too much water on sedums? We’ve been known to have the occasional extremely wet summer here in the Northeast; I know that sedums deal well with drought, but wonder how landscape sedums react to too wet of a season. I’ve had houseplant succulents ‘melt out’ from getting the same amount of water as my other houseplants. Is this possible with sedums?

Comment on Question: Sedum Performance by Mollyavalon

Mollyavalon — Mon, 24 Nov 2008 21:13:40 +0000

So, manufactured soil is actually custom-mixed soil. Interesting. Thanks!