Most frightening and/or depressing story: If humans are subject to the same natural laws as all other species on Earth, we are doomed to certain extinction by our limited genetic variety, declining fertility, and overexploitation of our habitat. So, how different are we? I can spin up a hopeful story where are evolving and overcoming our limitations through intelligence and technology, but time will tell if this is right or wrong.
Most hopeful story: Metformin, a diabetes drug, might be able to preemptively treat a variety of diseases colloquially referred to as “old age”.
Most interesting story, that was not particularly frightening or hopeful, or perhaps was a mixture of both: Biotechnology might be on the cusp of producing plants that can make more efficient use of the sun’s energy. This could be good for the food supply, and bad if the damn things escape into the woods. And in tangentially related news, yields of salad vegetables can actually be higher in urban areas than on conventional farms. Those coastal elites and their fancy salads, why can’t they just live on simple basic grains like Doritos the way the rest of us do?
How Much Food Can We Grow in Urban Areas? Food Production and Crop Yields of Urban Agriculture: A Meta-Analysis
Urban agriculture can contribute to food security, food system resilience and sustainability at the city level. While studies have examined urban agricultural productivity, we lack systemic knowledge of how agricultural productivity of urban systems compares to conventional agriculture and how productivity varies for different urban spaces (e.g., allotments vs. rooftops vs. indoor farming) and growing systems (e.g., hydroponics vs. soil-based agriculture). Here, we present a global meta-analysis that seeks to quantify crop yields of urban agriculture for a broad range of crops and explore differences in yields for distinct urban spaces and growing systems. We found 200 studies reporting urban crop yields, from which 2,062 observations were extracted. Lettuces and chicories were the most studied urban grown crops. We observed high agronomic suitability of urban areas, with urban agricultural yields on par with or greater than global average conventional agricultural yields. “Cucumbers and gherkins” was the category of crops for which differences in yields between urban and conventional agriculture were the greatest (17 kg m−2 cycle−1 vs. 3.8 kg m−2 cycle−1). Some urban spaces and growing systems also had a significant effect on specific crop yields (e.g., tomato yields in hydroponic systems were significantly greater than tomato yields in soil-based systems). This analysis provides a more robust, globally relevant evidence base on the productivity of urban agriculture that can be used in future research and practice relating to urban agriculture, especially in scaling-up studies aiming to estimate the self-sufficiency of cities and towns and their potential to meet local food demand.
Water, energy, and fertilizer-efficient urban agriculture for some fresh produce in cities seems like a pretty good idea. Urban aquaculture seems practical to me. Growing enormous amounts of grain and protein does not at the moment, unless we are going to do it in high-rises under lights. That might be technological doable but farm fields out in the countryside are probably going to be more cost-effective for a long time to come, especially when the environmental costs are mostly not counted.
Even growing a few percent of our calories in cities might help to buffer any future food shocks by giving us extra time to react to them, and by reducing panic and economic disruption it could cause.
Forbes has an article on vertical farming under lights, claiming that a 2-acre vertical farm can replace a 750 acre outdoor farm and use 95% less water. It doesn’t talk about pollution, but in theory it should be relatively easy to collect and recycle/compost/digest/burn solid waste, and collect and treat wastewater, from a farm like this. I know LED lights are efficient, but you do have to produce enough energy to replace the sunlight that would have fallen on 750 acres of the Earth, plus some extra because the system is not perfectly efficient, and you have to produce fertilizer of some sort. These things will have an ecological footprint. On the other hand, if this is in an urban population center, you potentially have a lot of waste streams you might be able to recover energy and nutrients from. Then you also have 748 acres of land somewhere that you can theoretically reforest or re-wetland. Then you might have a healthy fishery somewhere downstream that is no longer choked by sediment and nutrients from farm waste.
Gardening and being around my small urban garden definitely brought me some comfort during the long Covid-impacted spring, summer, and fall. A silver lining of being forced to work from home was being able to work outside some. Anyway, below I’ll just tell my story in pictures.
Black Swallowtails are not rare but they are just fun to watch, and their big fat green caterpillars are fun for the young and young at heart. In addition to bicycle tires, they like the fennel and celery in the garden, neither of which I had to plant this year. The fennel is a hardy perennial with a deep taproot that also spreads aggressively by seed. In fact, I had to start pulling fennel aggressively this year except for a couple spots where I decided it was allowed. The celery (which I mistook for flat-leafed parsley at the farmer’s market years ago) seems to be self-seeding and coming back each spring. There was no parsley in evidence in the garden this year.
Black Swallowtail
We saw quite a few monarchs around. This one is on butterfly milkweed, which really started to take over parts of the garden this year. The monarch didn’t cooperate and spread its wings for a nice photo. This should be a host plant, but sadly we did not see any Monarch caterpillars in evidence. I feel good doing my small part in a small urban garden for this endangered species. We made a brief trip to Cape May, New Jersey in October during the fall bird and butterfly migration, and this is just an amazing thing to see – Monarchs just flitting by every few minutes, adding up to millions I would imagine over time!
Some other plants you can see here are purple hyssop (slightly past its prime) and the fennel just starting to bloom. In the background is the neighbor’s ornamental grass, which is interesting but getting completely out of hand. If I didn’t constantly hack at it my garden would be gone in a few years.
Monarch on Butterfly Milkweed
Here’s another (slightly more photogenic) Monarch on a sunchoke flower. The sunchoke, which I planted last year, started to get aggressive this year. I don’t really mind because they are shallow-rooted and easy to pull where I don’t want them. I did notice some squirrels digging them up in the fall and “squirreling them away” in neighbors’ gardens, lol. The sunchokes and hyssop in particular attracted lots of bumblebees which were fun to watch but did not cooperate for photos. Mountain mint was another plant that seemed to attract lots of bumblebees.
Monarch on Sunchoke
We had a bumper crop of milkweed bugs this year. They’re harmless and I think they are super cool, but I can appreciate they might be creepy to people who just don’t like bugs. This is what the butterfly milkweed looks like after it is done flowering and starts to grow seedpods. There was also a lot of common milkweed in the garden which I didn’t plant but leave alone whenever I see it. I notice that friendly neighbors and their gardeners tend to pull theirs, which I will not judge (in case any of you are reading this) but all the more reason for me to do my small part to support native plants and ecosystems.
Milkweed Bugs
Completing the butterfly milkweed life cycle, here the seed pods are bursting open and preparing to scatter their goodness to next year’s garden. The milkweed bugs are still around, but I noticed after about this point they just started to crawl away and scatter. I don’t know exactly where they go. The white flowers you can see here are garlic chives, which are super cool and attract lots of bees and harmless little wasps. They (the garlic chives, not the pollinators) are getting just a bit aggressive though.
Butterfly Milkweed Seed Pods
This giant pumpkin vine just volunteered, probably as a result of throwing last year’s Halloween pumpkin in the compost. Either that or the squirrel’s who shredded other peoples’ Halloween pumpkins (we have learned not to put ours out too early) might have buried the seeds. It didn’t grow any pumpkins though, maybe missing some key nutrient?
Volunteer Pumpkin
The spotted lanternflies invaded Southeast Pennsylvania with a vengeance this year. This is an invasive species from Asia that is almost certainly here for good now. They didn’t do any obvious damage to my trees (including this Asian persimmon) but we will see what the future holds. They don’t bite, unlike the mosquitoes we had in abundance. We mostly worried about one particular species of virus this year, but others like west Nile, Lyme disease, and Zika are still around, and with climate change I will not be surprised if tropical diseases like Dengue are on the way. Can we apply the new vaccine development technologies to work on some of these, please?
Spotted Lanternfly on my Persimmon Tree
We had lots of stuff in pots. From left to right here, Thai “holy” basil, Asian long beans, Thai “sweet” basil, sunflowers (“Autumn beauty”, which lived up to their name and I recommend, Thai jasmine. Lots of bell peppers also volunteered this year, but no hot peppers – in past years lots Thai red peppers have been in evidence.
Pots
Maypop was my “try again” species this year. With the last few winters being so mild, I am hoping to see it again this spring. The new species I decided to add this year was a low, evergreen groundcover called bearberry. I didn’t take good pictures of it, and anyway it is not photogenic at this point, but I have high hopes for its future.
Maypop
And finally, the dwarf Asian persimmon turned a nice shade of orange to wrap up the year. It is 3 or 4 years old, and flowered but did not set any fruit this year. My other tree is a dwarf Asian pear. It had some kind of leaf spot and looked a bit sickly much of the year, but it did set a fair amount of fruit, of which the score was humans 2, squirrels the rest. They were good, and that is an all time high score for the humans!
Michel uses “Coop Tender,” a system that allows owners to control their coops via smartphone, dictating temperature, ventilation and lighting.
The system includes an automatic door and “predator motion detection” that turns on a security light and sends owners a text when danger lurks. Despite their relative privilege, even these chickens are circled by predators like hawks, coyotes, raccoons and bobcats.
Now that there is snow on the ground and any possibility of actual gardening has ground to a halt, I find myself thinking about the growing season that just passed and the next one coming up. This wasn’t a great gardening year for me. A brand new human being sprouted in my household in January and ended up requiring a lot of care and maintenance throughout the growing season, along with the care and feeding of a four-year-old seedling we already had. The actual garden got mostly neglected. Weeds took over around mid-summer and I didn’t put the effort into beating them back that I would like to.
Still, the two trees and various perennials I planted in 2016 just chugged along all season even under and among the weeds. Their roots should be growing and strengthening, the seed bank will gradually shift toward “weeds” I like, and I think there is plenty of hope that the garden I originally envisioned will gradually start to take shape in the next few years. It helps that what I envision is only semi-tame to begin with.
What went well:
The Asian pear tree grew like crazy in its second season, and is now about as tall as it was advertised to be. Early in the season, it was swaying alarmingly in high winds, but the bottom seemed stationary so I didn’t stake it. Later in the season, it seemed to strengthen and stiffen, and is now doing well.
The Asian persimmon grew a little bit in its first year. Any growth was welcome after my first attempt with an Asian persimmon was dead on arrival. We will see how it does next year.
Other perennials did just fine in their second year, including lemon balm and butterfly milkweed. The yarrow the previous owners had, which I moved, continues to do well. My chives and garlic chives both did well and flowered. Violets and green and gold both started to fill in nicely as ground covers. The previous owner’s black-eyed Susans are doing well and even getting a bit aggressive. They have a bunch of bee balm that is doing well, which is good because I think I destroyed all the bee balm I planted myself when trying to pull out some aggressive daisies. It’s not that I hate daisies, but they don’t have much redeeming ecological value and one small clump is enough for me. A couple of the previous owners’ purple coneflowers are still hanging on too.
My greatest triumph of the year was getting wild strawberries sprouted and established.
My plan to attract black swallowtails with parsley, dill and fennel was a qualified success. Something ate the dill early on, but the parsley survived all year, and the fennel grew like crazy (I didn’t know fennel was such a large perennial, I plan to keep it but may move it elsewhere.)
Thai basil and Thai sweet basil did awesome in our big tubs as usual.
Maypop – Planted a couple vines as a long-term substitute for clematis and they took off. Will see if I end up regretting this some day.
I’m almost embarrassed to say my dandelions and chicory are doing well, but hey, I have had a soft spot for these “weeds” ever since I was a kid and they are always welcome in my garden.
I had a pitcher plant and Venus fly trap that were very happy for awhile growing in Sphagnum moss under my air conditioning condensate line. The Venus fly trap petered out sometime in the fall, but I brought the pitcher plant in for the winter and it seems to be bumping along.
What didn’t go well:
No luck even sprouting anise hyssop or mountain mint. I have never read anywhere that these seeds are hard to sprout.
I made a half-hearted attempt at miner’s lettuce again. A couple anemic seedlings just petered out as soon as it got hot.
Surprisingly, no luck with sunflowers, because squirrels just ate them right away.
I tried cilantro in window boxes, but it just bolted right away. The flowers were semi-interesting for a few weeks and attracted interesting little pollinators, but then they just died and looked terrible the rest of the year.
No luck sprouting Thai chilis.
No luck sprouting parsley, but of course it is easy and cheap to buy at almost any farmers market or hardware store.
Surprisingly, my white clover petered out in the hot summer and dry fall, which is one thing that allowed so many other weeds to come in. The roots are probably doing fine and we’ll see if it bounces back in the spring.
Sunchokes – these came roaring back in one of the big tubs in the spring with no intervention on my part, then gradually started to look really anemic and gross in the summer before dying completely. This doesn’t mean the roots are dead and won’t come back next year, of course.
White mulberry – one of these bounced up to small tree height in a matter of weeks in late summer and early fall. I don’t want it and need to do something about it ASAP before doing something requires a chain saw rather than a hack saw.
French sorrel looked anemic and weed-covered in the summer, but seemed to perk back up a bit in the fall.
Plans for next year:
Sunflowers – just direct seed tons of them, more than the squirrels can eat. Sunflower seeds are cheap. I still like my idea of using them as sort of a biological fence to keep out neighbors’ weeds.
Miners lettuce – still want to try to get a stand of this established. I may try a combination of direct seeding and transplants.
Sea kale – the one new seed I plan to order this winter.
Anise hyssop and mountain mint – I want to take yet another shot at these. Maybe just start a whole bunch of them and try some direct seeding too. And if none of that works, maybe break down and mail-order some plants.
Thai basil and Thai sweet basil – I’m excited because I saved seeds from plants last fall. If they don’t sprout, these are easy to buy our local Asian market.
Thai chilis – I want to try getting these to sprout again. With all the recalcitrant seeds that don’t want to sprout, I think I will stop being so stingy with seeds, and start putting large numbers of them in plastic bags with moist paper towels on top of a heat mat.
Parsley and dill – I like using these to fill in empty spots where I might put perennials in the future, mostly to attract caterpillars. Maybe I’ll put these in the window boxes. I want to try getting parsley to sprout, but if not I’ll just buy some.
Fennel – like I said, the one I have is doing fine and I just want to move it.
White mulberry – I’m going to try cutting the monster to the ground and “mulching” it with Epsom salts. Supposedly, these can dry out a tree stump without actually being toxic to anything nearby.
So, next steps are to research how early I can set out some of these plants, and start counting back to when I should be starting the seeds. Fun stuff.
This article is a bit disturbing, because I have been composting coffee grounds for years with seemingly good results. Then again, I wasn’t doing an actual controlled experiment.
There are frequent anecdotal recommendations for the use of locally produced spent coffee grounds in urban agriculture and gardens, either through direct soil application or after composting with other urban organic wastes. This study investigates the scientific basis for direct application of spent coffee grounds (SCG) and the influence of different: i) plant pH and nitrogen preferences, ii) soil types, and iii) application rates. We specifically consider impacts upon plant growth, soil hydrology and nitrogen transformation processes.
We grew five horticultural plants (broccoli, leek, radish, viola and sunflower) in sandy, sandy clay loam and loam soils, with and without SCG and fertilizer amendments. The same horticultural plants were grown in the field with 0, 2.5, 5, 10 and 25% SCG amendment rates. Plant biomass growth was related to soil pH, soil moisture, nitrogen concentration and net mineralization, as was weed growth after harvesting.
All horticultural plants grew poorly in response to SCG, regardless of soil type and fertiliser addition. Increasing SCG amendment significantly increased soil water holding capacity, but also decreased horticultural plant growth and subsequent weed growth. There was evidence of nitrate immobilization with SCG amendment. Growth suppression was not explained by soil pH change, or nitrogen availability, so is more likely due to phytotoxic effects.
Fresh SCG should not be used as a soil amendment in ‘closed loop’ urban food production systems without consideration of potential growth suppression. Further research is required to determine the optimal composting conditions for SCG and blends with other organic wastes.
I’m not a very scientific composter. I just throw stuff together in an old recycling bin, then when it fills up I move it to another bin, and then a third (despite a few raised eyebrows from neighbors, I rescued all these bins on my old street after they were abandoned for at least a week, and filled with litter and dog crap). At that point it’s usually a nice crumbly organic mix that I can use. I don’t follow any of the rules. I don’t mix green and brown items in the right proportions, I let it get wet and dry according to the rain, I compost perennial weeds, and my pile almost certainly doesn’t get hot enough. I probably wouldn’t give the stuff away because there are weeds in there, but I don’t worry about putting it back on my garden, which is where the weeds came from. If they want to keep pulling carbon dioxide out of the air and turning it into organic matter for me, I am fine with that. I would rather be outside pulling weeds than doing almost anything inside.
Mid-February, time for a gardening post. It’s kind of like when you start following your favorite sports team before the season starts, and you are excited because anything is still possible. I am especially excited though because I have a new house, it has a garden, and it is really the first time I have ever had a garden. I’m going to grow some annuals, mostly in pots, but what I really want to focus on is perennials. I’m picking mostly perennials, mostly natives, and mostly plants that are edible in a pinch, although garden for food is not my top objective (my top objective is butterflies and other pollinators, followed by interesting appearance including flowers, followed by food potential). Which brings me to cold stratification. I have started a bunch of seeds in the basement under lights over the last two weeks, but so far nothing has happened. These perennial seeds seem to be tougher than the annuals I have been used to in the past. One reason is some of them apparently need cold stratification.
Where I live the snow is rapidly melting, leaving behind a landscape that seems almost barren and asleep. However, for many native plants and quite a few garden perennials, it is this act of freezing and thawing that awakens them and actually increases their ability to survive and reproduce. Cold stratification is the term used to describe this very basic need; the need for winter. Winter has the ability to soften the outer seed coat of some of nature’s toughest seeds through the action of freezing and thawing in a moist environment. For many plants that require stratification, this process can take up to 2 months and typically occurs between 34 and 41 degrees Fahrenheit. During that time, the seed coat softens and embryonic growth is stimulated. Eventually, the embryo bursts through the softened coat and begins the process of germination.
For those of us who enjoy starting our own flowers, there are some classic perennials that require a period of cold stratification to increase germination. One example is Echinacea, a personal favorite of mine. Echinacea is a plant gifted with many benefits. Most home herbalists are aware of its medicinal properties and gardeners love it for its beauty, low maintenance requirements and as a mid to late season nectar source for beneficial insects. For these reasons, Echinacea has a place in nearly every garden and farm. But purchasing mature Echinacea plants from a nursery can be expensive and often some of the most interesting varieties (Rare or endangered native prairie Echinacea varieties have only been available in seed form recently.) are not available commercially. For these reasons, I started growing my own Echinacea from seed a number of years ago. In the beginning, I had mixed success. Without a period of cold stratification, the germination rate for this garden beauty can plummet to less than 30 percent. However, with stratification, it is possible to germinate nearly 100 percent of all Echinacea seeds that are started.
So I’m going to try throwing some seeds in pots in the backyard, even though it is freezing. But 30% doesn’t sound that bad to me. With a packet of 100+ seeds costing $2-4, I can afford to plant 3 seeds for every one that comes up. Still, I’m waiting a bit nervously for that first one…
Just an interesting site I came across in random web surfing. If you really had a clean slate and could turn a computer loose to design an efficient city for you, it might look something like this.
Edible Infrastructures is an investigation into a mode of urbanism which considers food as an integral part of a city’s metabolic infrastructure. Working with algorithms as design tools, we explore the generative potential of such a system to create an urban ecology that: provides for its residents via local, multi-scalar, distributed food production, reconnects the traditional waste-nutrient cycle, and de-couple food costs from fossil fuels by limiting transport from source to table.
Our research is conducted through the building up of a sequence of algorithms, beginning with a Settlement Simulation, which couples consumers to productive surface area within a cellular automata type computational model. Through topological analysis and interpretation of the simulation output, we explore the hierarchical components for a new Productive City, including: the structure and programming of the urban circulatory network, an emergent urban morphology based around productive urban blocks, and opportunities for new architectural typologies.
The resulting prototypical Productive City questions the underlying mechanisms that shape modern urban space and demonstrates the architectural potential of mathematical modelling and simulation in addressing complex urban spatial and programmatic challenges.
