A crash course in changing the world.
Hello, fellow EVOKE agents. Food security is the concern this week--and an ongoing concern in the world at large. Already, online, and in EVOKE, there have been many great postings about container gardening, sack gardening, and efforts around the world to mitigate the problems of poor soil, energetic pests, lack of space or access.
While being both inspired and awed by all the large scale efforts, gardening-foundation operations and commercially-available innovations, I still wondered if there was a small niche where an idea for a mobile garden-on-a-cart could find a spot in the sun.
So, taking a deep breath, here is a bit of my first-hand experience, for information, for collaboration, for inclusion, as a challenge. My apologies for generalizations--I am trying to be brief! Also, I am a small-scale, individual gardener--many have far greater expertise than I with large-scale agricultural operations througout the EVOKE community.
I have experience with using sack gardens (ground, suspended) in various climates--Africa, southern Japan, Southern Thailand, Canada, US, container gardens (ground and vertical), and have built a number of moving-garden carts utilizing a combination of potting and propagation methods.
Any type of container, new or recycled, can be used, as long as sufficient air can reach the roots of the plants, heat is not stored excessively, and water conservation/drainage considerations are met (water resevoirs with wicking to keep soil moist, water catch-pots on the outside for better drainage, etc). Group containers, or build small tiers to maximize exposure to sun as needed. Plan extra space, or netting or other supports for vining squash and heavy-yield varieties; place pots with climbing vines near the poles or tie strings/netting between the top piping/poles and the pots.
Second--Sacks and Bags.
Bags can be of varying size, permeability, and origin (recycled if they are strong enough for the season!!, purchased, re-used from one season to the next). When suspending bags, consider the weight of soil, water, and fully-developed, fruiting plants when chosing the hanging methods and the pipe-scaffolding you will build on the carts. Repurposed canvas, denim, other recycled cloth can make good hanging supports for bags of all types; many purchased sacks have gromets around the top-hem, so you could use plastic hangers or even chains to hang these. Permeable bags are safe bets for aeration of roots, but need to be monitored for water/humidity levels, especially in hot climates. Non- or semi-permeable bags decrease water loss due to evaporation, but can build up large amounts of heat, and cause soil to be over-hydrated if drainage is not properly monitored.
Sometimes, especially with permeable bags, you can combine watering of top plants with cart-surface plants below, if thorough soaking and drying is the best watering style for the plant. Vertical plant groupings should also be considered, in this case (many herbs like extra water, some shade from hanging plants, some squashes will get leaf-molds, and wither due to extra water drips, lack of sun-exposure--it is easy to shuffle plants for maximization of productivity, if planning in advance.)
While my early cart models used (generally 4 or 6 or 8, depending on cart size) heavy-duty small-cart wheels (with brake levers), and these do work well in paved/urban settings, the garden carts will work better when modified with thick, tall, bicycle-style wheels (four, at corners, or sometimes only two--in the middle--or three--like a tricycle--augmented with "kick-stands") in rural and peri-rural settings where there are few paved areas, and roads are dirt or packed stone, or just paths over sand, mud, or rocky areas (such as where we lived in southern Thailand and sandy Africa).
Impoverished, under-served or homeless people with whom I built a couple of carts in various places I have lived have enjoyed the autonomy of a mobile garden. People don't need to own a house, have a yard, or lease a community space to have a beautiful, productive cart garden.
Water is needed, sunlight, and the materials to build and stock a cart with its pots/sacks, dirt and seeds. (We gleaned lots of the materials, pooled labor, I helped with seeds, pots, a little composting-bag and other starter-items--and we "built" the dirt supplies by adding to composting piles I had started. Harkening back to "teach a man to fish" and "teach skills, don't give handouts..." , participatory assistance does seem the best method of sharing skills/resources, and it is easier to listen to people and pool ideas when you work together...).
The carts (as mentioned in a very early comment to Agent Amanda Jeffries--sorry for the repetition here) can be of various sizes as long as mobility is feasible. I used recycled pipes to erect a scaffolding-level or two around the perimeter (and across the middle, in larger carts) for suspending sack and hanging-pot containers. These can be stationary or movable, depending on plant type, access to/intensity of sunlight, etc.
I think the carts can be combined with low-tech power generating mechanisms, etc., to multi-level usages. (power can be used, stored for later, perhaps sold/traded at community power-collecting stations--many small batteries can store DC and then transfer the stored current into a central collector for large-watt usages).
Also, building and using the mobile garden carts could teach and sustain entrepreneurship as well as improving health/diet of the grow-cart users. There is no real age limit on using the adjustible-sized, easily-accessible carts; children can learn gardening skills, elderly can preserve their autonomy; adults can improve family diets and still work at their "day" jobs. And, since co-planting of pollinator and insect-repellant flowers (veggie-munching beetles don't like marigolds, bees and butterflies do...) can be dual-purposed if gardener wants to sell cut flowers, as well, small business skills might be learned, and some additional income generated...
Always important for the next season: it is also easy to harvest seeds--you always know where your plants are. Dirt should be refreshed, and containers cleaned between plantings (or recycled through composting operations) to maintain health of new plants.