I submit my case for urban agroforestry ur honor

Pile on the left is mostly from the neighbors' tree, we have a deal where I get the nuts & give them back a bunch shelled

The smaller pile & bag are a couple hours' worth of picking from 3 trees in a park during/right after a windstorm.

Currently ~80lbs of nuts & still picking.

I really need to get some 5gal buckets, did NOT think "casually picking up 100 lbs of nuts" was a thing that could happen lol

These trees look to be left over from before the park was officially made, it contains some old homesites that were since condemned & razed. They never got around to taking out the pecan trees in their yards though.

Urban agroforestry can go very *very* wrong: most food trees drop a lot of wet mushy stuff. They're buggy, rodent-y, smelly, & stain-everything-y.

Pecans & maybe hazelnuts are a big exception.

bout to go on a walk brb

Folks asking about pollutant & heavy metals content:

This is a valid question, and how heavy metals get into/onto plants does not really seem to work the way people think it does. Let's do a brief review?

Heavy metals are a major concern with for categories of food crops:

-Leafy greens

-Root vegetables

Nuts are not in either of these categories.

Most* plants don't, like, actively suck the lead out of the soil. They don't need or want it. They get a trace amount of whatever lead is dissolved, along with other minerals, in the moisture in the soil.

*exceptions to be covered shortly.

A few kinds of plants are what we call hyperaccumulators: they DO gather up a disproportionate amount of minerals from the soil (including lead, if it's there).

That's why when you hear people talk about using plants to remove heavy metals from soils, they're always talking about a few specific hyper-accumulator plants. Not just "plants in general." Most of them *don't do that.*

Here's the downside: leafy greens tend to be hyperaccumulators. Here's just one example of what that looks like on contaminated soils. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808952/

So yeah spinach grown in lots known to have had industrial activity, or lots of traffic pre-1980, is a big no-go.

Root vegetables, similarly, tend to accumulate heavy metals fairly well.

This is why you hear all the warnings against growing carrots, beets, spinach, etc in urban gardens.

It's because a lot of popular garden vegetables happen to be in hyper accumulator categories & shouldn't be grown on contaminated sites.

This is very different from "Every edible plant is a hyper accumulator, and every urban site is unfit for growing any kind of food."

See this survey of fruits & nuts grown in inner Berlin, a historical site of heavy industrial activity.

https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.1086.8704&rep=rep1&type=pdf

Basically they found that places right along roads (=heavy traffic) or houses with lead paint tend to make fruits & nuts a little higher in heavy metals

and still, out of 172 samples, only 1 exceeded the EU's stringent limits for heavy metals in foods.

The history & present characteristics *of a specific site* have more influence on heavy metals than "is it in a city or not."

In fact, on the whole, fruits & nuts grown in Berlin's city limits had similar heavy metals content to the rural-sourced stuff at the grocery store.

Could be related to how many orchards were being sprayed with lead and arsenic in the late 1800s/early 1900s, and are still being used as crop ground.

The whole "city = adulterated, rural = pure & unspoiled" concept is uhhhhh... deeply problematic and scientifically false.

Also, this article is just from a survey. But note how nuts are consistently the lowest in heavy metals content of all the categories of crops surveyed in the article.

This study did note that a lot of urban heavy metals contamination, insofar as it happens, comes just as often from car exhaust & contaminated dust (house paint, etc) blowing onto the fruit & nuts while it grows

as it does from the soil itself.

So washing/peeling is pretty effective at removing heavy metals contamination.

Unless the stuff was grown on an actual industrial site, roadside, or next to a crumbling building with lead paint.

Like, the place I'm getting these nuts from is a park. People like to walk their dogs there.

You best believe I'm washing them before use. Just on account of the thin layer of dog shit all over everything in the park, nvmd heavy metals.

Yes, you should definitely wash urban-grown food.

Just like like any farm, you want to wash the goods to get rid of wildlife poop, cigarette butts, etc.

yep you pick up cigarette butts in rural field harvests lol

The message behind urban food & contamination isn't

"don't grow food in cities."

It's KNOW YOUR SITE.

Which is also exactly how you have to do it in rural areas! Don't plant a new orchard on an old one that's coated in lead & arsenic, or next do a feedlot!

But unfortunately, because we already have so much cultural baggage around how cities are "dirty,"

what people hear is scaremongering around the whole concept of urban food systems.

It's not that cities are actually riskier or more dangerous than the countryside.

It's that our culture has taught us to think of rural areas as "safe" and "clean," when they're NOT. They're just normal places like everywhere else.

But when we contemplate growing food in urban areas, suddenly that "this is a safe space" halo goes away.

We actually *start thinking about risks* & freak out about them.

But that perception of risk doesn't come from urban food being innately more hazardous.

It's because we've been taught to turn our brains off w/r/t food risk when sourcing it from rural areas.

I'm seeing a lot of urban planning & architecture ppl staging themselves as experts on urban ag this week.

It would be really cool if y'all actually checked in with a crop scientist every once in a while before running with OR away from ideas

Don't just assume you "get ag." Farm site risk analysis is an actual job that we do all the time. It takes detailed training in crop science, hydrology, & geochemistry.

Like, I just updated an urban farm client's risk assessments last week.

There's LOTS say re: how UP/arch folks think "urban ag" can only mean greenhouses & twee gardens in skyscraper districts, which 100% comes from the world of glossy architecture magazines & has no bearing on the realities of food production

but twitter's cutting me off now