Long time lurker, first time poster. We're finally getting infrastructure put in and will be moving to our permanent spot on our property in a few months (finally a break from RV living). We plan to plant most of our acreage in forest garden, but are planning a relatively large annual garden to hold us over until the perennials start producing. My end goal is an annual garden that requires no irrigation outside of 9 months of relatively steady rain we get. Holding onto that water during the dry season is going to be key.
I keep revising my design and adding new and different features. But the current design I'm toying with would have permutations of 3 3-foot rows of annuals sandwiched between rows of nitrogen fixing trees with comfrey/green manure. The trees (possibly alder) would be pollarded at maybe 5-6 feet tall and provide mulch for the annuals, in addition to the green manure growing around the trees. As the trees will not be allowed to grow naturally, they'll be planted on a really close spacing, maybe 5 feet. As they mature, trees can be removed as needed. They could also act as temporary fence posts to, say, allow chickens to scratch in a section of the garden.
The two paths between the annuals would be dug out and filled with woody material from a logging operation to create a kind of inverted hugelkuktur to increase the water holding capacity in between rows of vegetables.
The original design didn't include nitrogen fixing trees in the annuals area, but would have instead depended on bringing in mulch from other parts of the property, which would be inefficient.
I've had decent results with the small dry garden I've had for the past couple of years (certainly not the same yield I get when I irrigate, but respectable, considering) but I'm hoping a few little design nudges will improve the productivity in the new garden area by increasing the amount of water available to plants.
Anything you would tweak about this experiment, or parts of it you've already tried that didn't work?
I believe Geoff Lawton, among others, builds his annual gardens on contour, both to capture water, as well as prevent erosion; the rows/beds are curved to fit the contour of the slope. I don't do this with my own annuals garden because I get plenty of rainfall during the growing season. Having trees or a hedge close to your garden beds may deprive the beds of water. I have a row of fruit trees growing against a fence, like espalier (in 2 dimensions, anyway), and I keep them pruned to the height of the fence at 2 m. They don't adversely affect the moisture of the bed at this size, though they are also planted about 1.5-2 m apart, not close like a hedge.
Oh, and I know you didn't mention this, but when I moved my kitchen garden to right outside my back door, my productivity really jumped. The old location was only about 10 m away, but it wasn't within direct view of the house, and to be honest, required too much effort to visit every day! I go through my kitchen garden multiple times a day now, as I go about my daily business, and things get harvested on time, or weeds/pests get noticed right away. I highly recommend placing the annual kitchen garden as close to the house as possible.
All in all though, I figure you might as well just jump in and try it. Better to do something imperfectly than to not do anything at all. And I'm always trying new things, and learning from my own mistakes, which I think is how most of us learn the best :) It shouldn't be too hard to change in the future if needed.
My irrigation last summer was with buckets carried by me from the stream 200 metres away, so I didn't irrigate much.
A spot where I have a tree blocking the hot afternoon sun did the best out of all the garden. This was the only spot where I successfully grew seedlings in the hottest few weeks with no rain, they still needed some hand watering though.
The potatoes I started early in spring did really well, but the ones started very late didn't grow much.
Brassicas and roots started early and mid spring did well.
Zucchini seemed to put up with a small amount of hand watering, but didn't like having no water at all.
Everything seemed to do much better once I got mulch in.
Tomatoes did reasonably well. Cherry ones did better than larger ones.
I couldn't get winter brassicas started anywhere except under the tree I mentioned, until we were getting more rain. Lettuce did not go well at all. Winter squash didn't go very well.
If we have no irrigation again this summer, my efforts will be focused on getting as much as possible planted in early and mid spring, and keeping it mulched.
My focus with design, if I were starting from scratch, would be to block drying winds, have beds on contour, and block the hot afternoon sun, as well as having lots of mulch and organic matter in the soil.
Personally, I would scrap the idea of trees that close to your annual garden plants. They don't mix well in my opinion. Something like sunflowers or corn could be grown on the north side of your shorter plants and chopped for mulch when you need it.
Oh hey! I didn't think I got any replies, but apparently the notification email didn't go through or ended up in my spam folder.
I will be planting most of the fruit trees and other perennials on contour, and intend for those to make up the bulk of my production. I've seen zero-irrigation gardening work well in my climate, but that's with decades of adding organic matter to the soil and heavy mulching (and saving seeds from crops that thrived in those conditions). I've also seen planting annuals under trees work effectively, though the trees are pruned very open to allow plenty of light through. If the annuals were suffering, I couldn't tell; if anything the trees seemed to help prevent evaporation and provided a net benefit to the annuals. It wasn't a thick canopy and the annuals didn't seem to be hurting for lack of sunlight. That was with fruit trees. I don't know if it would be as effective with nitrogen fixers.
I do tend to favor a messier polyculture design, but I need to scale up my production and keep it more organized for the sake of harvesting and seed saving. That's why I'm leaning towards a return to rows as opposed to polyculture on contour. I imagine that as I develop the property, a lot of the annuals will end up being planted throughout the forest garden (where available light allows) and the actual beds will be reserved for calorie dense/staple foods.
As far as location of the garden... I'm not sure how happy I am with my available options. I think when they brought the excavator in to prepare the ground for building, they really did a number on things; I think they've complicated my plans for garden access and water catchment. I'm in charge of food, not building, so a lot of time they don't ask for my input on things that affect my ability to produce food. We'll see. And since the garden is going in before the house does, I have to try to magically make present and future access tenable. I think I'll only be putting in about a third of the garden to begin with, and I can adjust the other two thirds based on how accessable things are from the house. I think they're finally done with the excavator, so now I can go back up to the site and reevaluate.
I'm still debating including trees in my design. I might experiment with it. I can always take them back out, or at least thin them, if it seems to be negatively impacting production. Weeds/spent crops will be going to the chickens to supplement their feed, so while it will eventually end up back in the garden, it won't be around for use as mulch.
Also, the main reason for the sort of inverted hugelkuktur is that we have large slash piles from a logging operation that need to be used up/out of the way, so this simply turns that problem into a solution (if a solution that requires a fair amount of digging.) I at least want to be in a position to get garlic and favas in for this coming season, and then see what things look like come spring.