Greenmantle, as explained on our main greenmantle page, is about creating a living cover of plants on rooftops. This insulates the building, cleans the air and water, and increases animal habitat.
Increasing numbers of companies and organizations are figuring out how to do this, especially where the rooftop is purpose-built for this. That is not what you'll find here. This page focuses on using low-cost or, ideally, "waste" materials to create greenmantle for existing rooftops, done without special skills, tools, or preparation.
Everything here assumes a reader in New York. That's just because this site is made in New York. Please feel free to substitute your locale where appropriate.
The goal is a system that works even when built by the unskilled, installed by the apathetic, and placed where they will be forgotten. So how do you do that? Keep it cheap. Perhaps the biggest difference between greenmantle and a conventional rooftop garden is that greenmantle is first and foremost pragmatic. So that means never sacrificing efficiency and ecological soundness for appearance. Anything requiring frequent watering, maintenance, or use of pesticides or herbicides is out.
Nothing done five thousand times is easy. This isn't just about the end result; it's about scale. Effective greenmantle covers yards and yards of space, so every choice, from maintenance to weight per square foot to water usage has a greater impact. The plant that requires "only a few minutes a week" of hand tending cannot be chosen when hundreds of that plant will be used.
Let Mother Nature decide. Rooftops are extreme examples of microclimate environments. One rooftop varies as much from another as Bermuda does from New Mexico. And on that single rooftop the differences in humidity, sunlight, and temperature between places like the front of the heating vents and the shadow of the cornice are huge. So we suggest that instead of trying to find the magic answer of "the" species that is suited to "the New York environment", we'll just start with plenty of options and let the plants sort it out for themselves. That means liberally mixing in the seeds of literally dozens of species. It also means mix 'em in deep, mix 'em in near the surface. Seeds are cheap. Replanting is not. Protect the roots, the rest will get by. A major factor in plant viability under hostile conditions is protection of the root area from swift changes in temperature or humidity levels. So our designs are meant to provide a certain level of protection in those areas. That means both designing in a significant R-value in top, bottom and sides and insuring that that R-value will stay useful when wet.
We love warehouses. The target environment is institutional buildings like factories, schools, and warehouses with large footprint flat rooftops, minimal or no foot traffic, and no previous superinsulating having been done. This is because such buildings would gain greatly from such retrofitting, are numerous, and have managers who are very cost-sensitive with considerable autonomy. In other words, if it makes sense to them they can go ahead and do it without fifteen committee meetings.
Stack 'em, rack 'em, get 'em out the door. The last decision is to focus on modular "shrink-wrapped" planters, meant to be stacked by the hundreds at depots accessible to building managers. This way somebody is free to come by, get one or two, try them out, and maybe come back later and get more. We'ld love to see these things end up at the local Home Depot. Get yer 28" by 28" planters here! On sale this week for $4.99!
What We Propose Based on some very small scale experimentation, we've made a possible recipe for large-scale, low-cost greenmantle.
Please note that all numbers here are approximate, meant to give a sense of the suggested range rather than a precise value.
We suggest:
Specifications and Notes Planter height is determined by soil height, which has led us to a preliminary suggestion of 18" for a soil height of about 14". Smaller width eases handling during shipment, storage and maintenance. However bigger encourages long-term plant and ecosystem health. This has lead us to a preliminary width/depth of 18"x18" to 36"x48".
In some cases, especially on larger rooftops able to bear greater loads, it may be worthwhile to consciously emulate a meadow, installing more than one kind of planter. Possible variations include: Given the nature of rooftops, it may be best to orient towards species of the sorts found in meadows and on steppes. Of course this opens the possibility of creating meadows of wildflowers and grasses visible from other locations, a possibility that, while clearly anathema to our already overburdened allergy sufferers, does create a significant public appeal.
One possible option would be to store prepared planters in refrigerated spaces, allowing them to be built whenever materials and labor are available and then kept in an inert state until useful. Since, especially laterally, these planters have formidable insulating characteristics, they could in some circumstances actually reduce the expenses of the location in which they were stored.
Another issue is pest species like pigeons and rats, both of which are sure to arrive and certain to find planters a desirable nesting ground. I know of no counter to this beyond encouraging access by predator species like cats. It does seem that including toughened varieties of species like catnip can only be of benefit.
Everything here is built around the goal of creating planters using local New York waste in a ways that require no elaborate off-site processing. Please note that except for creating sheets from plastic waste, nothing here requires the level of skill, staffing, or space of the average auto body shop. All tasks can be done by volunteers, workfare participants, or students. With the addition of a two or three hundred dollar hydraulic lift, all of these tasks could be carried out by middle-schoolers.
While some other aspects have been worked out beyond the detail provided here (including possible use of existing containers such as those used to deliver fish as quick-deploy planters) this writeup should give you enough information to get a general sense of this approach. If you have any questions, then e-mail me and I will be glad to discuss them.
Overview | approach | proposal | specifications and notes
We'ld rather face a few years of scruffy planters while the best options emerge than have to do the whole thing over. Besides, "junk species" like morning glories and bean vines will be more than happy to keep things looking green while the perennials and grasses get established.
Overview | approach | proposal | specifications and notes
Overview | approach | proposal | specifications and notes
> planters made with quick-deploy pyramid trellises and a mix of ivys
> planters with small seedlings already in place
> planters with mixed or uniform established ground cover such as sedum, juniper, or english ivy (Please note that we strongly discourage any approach that would lead to the establishing of a monoculture since, no matter how robust this mean seem in the short term, it creates critical vulnerabilities that are contrary to our philosophy of how to achieve long-term stable greenmantle.)
> planters containing one or more dwarf varieties of tree or shrub
> planters optimized for their ability to support particular organisms like butterflys, birds, bees, or perhaps even ants. Ants in particular can give a rooftop a modest self-cleaning capability, which would be particularly useful over restaurants. Also better to chose a species of ant at the beginning, thereby encouraging a desired variety, rather than have some random species colonize a vacant niche.
Overview | approach | proposal | specifications and notes
return to first greenmantle page
return to Reed and Wright