It’s permablitz planning season and you’re invited!

•Are you part of a community group that could benefit from increased access to your own fruits and vegetables? From reduced water or electricity bills?

•Are you an organization doing community organizing or direct support work that has an idea for the way that small-scale energy or food/medicine production could support your work?

•Are you a tenant or a renter in an urban area wanting to increase your access to fruits and vegetables, decrease water or electric bills, and learn about and demonstrate urban gardening techniques?

•Are you a property owner in a rural, urban, or suburban area looking to build your household’s resilience and also committed to building equity in your community by leveraging your property towards community benefit? (This could look like land sharing agreements, building a community gathering space, creating a neighborhood food distribution network with surplus, running a community research project on soil remediation, etc.)

The Resilience Hub is seeking proposals for projects to build community-scale resilience for this year’s season of permablitz work parties! To apply with your idea for hosting, fill out this form!

The Portland Permablitz Network organizes work parties to build projects that increase resilience through backyard or neighborhood food production, energy generation, water catchment, and community-building. We take a permaculture approach – a way of designing that mimics nature’s patterns. Together, we can accomplish in a day what it might take an individual or small group a whole season to complete. We will convene 5-6 permablitz work parties from May through November this year.

Do you know groups or individuals that might be interested? No permaculture experience necessary! Can you pass the word along?

To apply with a proposal for hosting, fill out this form by April 1!
Please contact Kate at kate@resiliencehub.org if you have any questions. Thanks so much!

City leaves often contain heavy metals, so compost with care.

A few years ago, I heard Maine farmer Will Bonsall “go off” in praise of leaves as a natural and free form of compost, better, he claims, than almost anything else you can buy in a bag. But he was talking about leaves acquired on or near his rural farm, not the ones raked off of city lawns.

I’ve been using about 100 bags of leaves as compost every season, collected from curbsides around Portland, where the locals conveniently rake it up and stuff it into paper, biodegradable bags.

What could be wrong with free, easy to access (often pre-shredded) leaves? Unfortunately, there’s a catch. (Isn’t there always?)

While reading an obscure book written in 1870 praising the use of “muck” by southern farmers (their term for half-rotted leaf mold), it ocurred to me that use of leaves in rural and urban settings shouldn’t be assumed to be equally virtuous.

The Lead Problem

In many areas of Portland, for example lead levels in soils are hundreds of times higher than “safe” levels, as determined by the EPA. I know this from samples I have had tested. Certain areas are worse than others, of course. Prior to 1978, most homes were painted repeatedly with lead-based coatings. Any house in Portland older than that likely STILL has lead content in the paint, the plumbing or elsewhere.

Lead doesn’t dissipate much on its own, so our soils are heavily afflicted with it. The older and denser the region of town, the higher the likely lead (Pb) content.

Back to my point about using leaves as mulch. Are they safe? Do they pick up heavy metals such as lead?

The answer, according to a study done in New Jersey on municipal leaf mulch, is yes, (unfortunately).

Researchers  found numerous metals in curbside leaves, including lead,  iron and aluminum. They suggest that this occurs because the fallen leaves “become contaminated with urban soil and dust from the road surface through various processes (raking, lawnmower pickup and vacuum) used for litter collection in the yard and at curbside.”

Of the various contaminants, lead is arguably the most concerning. How bad is the potential pollution in city leaves? They apply a standard of 45 Mg/ha, based on tests of sewage sludge–which equates–by my calculation, to about 45 tons of leaf matter spread on 2.5 acres of land.

Break that down to the garden plot level.  An acre is 43,560 sq. ft. If you were only adding this much material to your beds, you would add about 1.21 lbs/sq. ft  of leaf compost per year (108,900 sq. ft, divided by 45 tons/90,000 lbs.=1.21 lbs. per square foot).

Given this level of application, lead levels in your garden would not exceed the EPA rules for “annual pollutant loading rate”–at least for a few years.  In the worst case scenario, with the highest level of lead contamination the researchers found in leaves, an application of this much leaf matter would take 16 years of repeated use to exceed EPA levels.

Don’t get too relaxed, however. If you’re like me, you add significantly more leaf mulch than that to your beds.

Let’s say you have a 4 ft. x 20 ft. garden bed. At the intensity of leaf mulching suggested by the researchers, you would only add 96.8 lbs. of material to the bed (80 ft. x 1.21 lbs/sq. ft.). But I’ve often added many times that much free leaf mulch to my beds at the end of a season, haven’t you? A yard of compost weighs between 1,000 and 1,600 lbs., depending on water content. That means that if I happen to apply what amounts to a yard of highly contaminated (at the worse end of the scale) curbside leaves to my annual beds, I could exceed EPA safety levels for lead in my garden in less than two years. And this assumes that we can trust the EPA guidelines are strict enough, which is a matter of some debate.

What to Do Now?

All of this is incredibly frustrating of course. Human beings somehow seem to turn the most benign sources of natural abundance into new forms of poison. We’re encouraged to buy our way out of the problem, paying exhorbitant amounts for “clean” compost products in 80 lb. bags. What a racket! It’s not unlike what’s happening with our water supplies. We’re forced to either buy bottled water or install an expensive filter if we want to drink clean water.

So let’s not give up on urban leaf compost. We just have to be more strategic in where we obtain it. And also, here’s one caveat: If the leaves will be used in a garden that is strictly ornamental, you’re probably safe to use as much urban leaf material as you like. The lead levels are probably too low to be of concern for pets or casual contact. I would mainly be concerned with gardens used for food production. The details matter. Certain plants, such as berries and fruit trees, for example, are unlikely to draw lead contamination into the fruit. But other plants absorb lead like crazy, especially in their roots. Brassica nigra, or Black Mustard, is a good example. Mustards seem especially good at extracting lead from soils. So are sunflowers.

Where I would take special precautions, however, is with the introduction of urban leaves to  annual gardens where cabbages and leafy greens are grown for consumption.

Here are my suggestions for reducing the risk to your health and your soils, while still using urban leaf compost:

• Avoid gleaning from the old City. In Portland, for example, I would not use leaves gathered on the West End or Munjoy Hill, nor in Bayside, for that matter. A lot of the debris from the great fire of 1866, for example is buried in Bayside, and these “historic” areas are often toxic wastelands in terms of the lead contamination of the soils.
• Look for natural lawns. Much as we’d like to see all lawns replaced with permaculture gardens, that’s a long way off. In the meantime, gather leaves from homes with heavy grass cover that doesn’t look like herbicides have been applied. The grass reduces direct contact between leaves and soil.
• Favor new developments. Scout out new developments  on the urban fringe, where homes were built after 1978. I suspect someone has a map of Portland with an overlay based on the age of the neighborhood. If so, post it here in the comments please.

Sorry to be the bearer of bad tidings about urban leaves. I wouldn’t take them off your list of permaculture resources. Simply be more selective in where you acquire them. Head for the outer suburbs, and be careful about buying your mulch from organizations that use urban leaf compost as a major component of their mix.

Matt Power is a West End resident and board member of The Resilience Hub (resiliencehub.org), a Portland-based organization that brings permaculture and community together. He is also the author of “The Tiny House Tactical Guide,” and Editor-In-Chief of Green Builder Magazine.

Why participate in a Group Order? Get a discount, order great stuff, have your plants delivered to Portland, and support the work of permaculture education here in Maine.

1. For all inquiries regarding orders, email at kate@resiliencehub.com.
2. You can use the paper Fedco Tree catalog if you have one or the online catalog to put together your wish list. Order early, as popular items tend to sell out.
3. Log into Fedco Trees using your email address and follow the directions given here. When you review your order prior to checking out, click the “Part of a Group” button as your shipping option. Then go to “Checkout Securely” and type in our group order number: 49801.
4. You will not pay on the Fedco site, but you will click here to send your total amountto The Resilience Hub. We collect the money and make one big payment to Fedco in order to qualify for the discount.
5. You need to place your order with Fedco and make your payment to us by the ORDER DEADLINE OF JANUARY 11, 2019.
6. PIckup up your order in Portland at the end of April. Depending on how much of a discount we receive, we will process a refund* back to you via PayPal.

We will be organizing 2 or 3 members with trucks to drive up and get all our stuff on Friday April 26th. Your order will be available for pickup in Portland on the afternoon of April 26th and over the course of the 27th and 28th weekend. More details about the specific location and times for pickup will be shared closer to the date.

Kate will be available to help out with any order problems or shortages after the fact.

Here’s to more perennial food in the landscape!

* Depending on the size of our order, Fedco will issue a discount of between 10% and 20%. Then sales tax will be added back in, we will put a bit of money toward fuel for the volunteers who drive to Fedco and bring the order back down to Portland, and a bit of money toward a stipend for the order coordinator. You will get at least 10% back, support the Hub and contribute to a reduced number of vehicles driving up and back for pickup!