swale sizes for a food forest planting..

Hey Friends,
I've been thinking, a dangerous thing for me.
When I start planting my food forest, I will start some trees by planting, some through seeding. I may not have the ability to swale the entire landscape by the time I have to plant these trees and bushes.

does it matter how large a series of swales I make? Do I need to build 300' swales, or can I dig an eight foot long, 12inch wide, 8 inch deep swale 2 feet up slope of each planting? I may not have access to a backhoe right away, but I can apply a couple of shovels for fifteen minutes on each tree.

Can I use a lot of small swales instead of these 5 ft wide, 3 ft deep swales 75 feet apart? Are they as effective, and what would I be giving up?

thanks!
Richard

I have two plots. One drains very well and the other is a vernal pool. My opinion with swales is that they need to to be large enough to catch enough water to do the job, without drowning the roots of whatever trees you have. If you are in a high rainfall area, small is OK because they'll refill often. Arid areas need to catch as much as possible, need to be larger, need to leach salts, and must have 6+" of mulch to keep it from evaporating away. If you are watering, all you need is tree basins. We have 1) trees that can tolerate flooding (sycamores) 2) overall low lying area prone to flooding. 3) watering basins for the non-rainy season.

Also think about chickens. Ours love to scratch in moist soil at the base of trees and adjacent to animal pens and under mulch because that's where the worms are. Make sure your design gives them what they want.

like greg suggested, a lot depends on the specifics of your site and climate.

if full-blown swales are too much work for you, a mulch pit has many of the same advantages. the main idea is a large-ish hole filled with mulch next to the new tree. when there's precipitation or snow melt, the hole collects water, and the mulch absorbs it to release to the surrounding dirt over a long period of time. several trees could share one mulch pit.

I'm planning to do the mulch pit idea throughout my yard, actually my entire vegetable garden is turning into a mulch pit or buried wood bed. Seems to really help with holding water in our very dry weather.

You could plant vetiver grass. It grows almost anywhere, stops run off and silt dead in its tracks. A swale will naturally form on the up hill side not to mention vetiver's 12+ foot roots will help you store a bunch of water deep underground fairly quickly. Vetiver grass roots can establish quickly growing to 6 feet in under 6 months. So the benefits are: no digging; quick establishment and sequestration of runoff; non-invasive (it sends dense, fibrous, roots straight down so it won't harm plants around it) and it produces a a renewable mulch and fodder very quickly.

If your willing to dig as well as plant vetiver you can produce a highly effective swale in a short period of time.

Hope this was helpful!

James Colbert wrote:You could plant vetiver grass. It grows almost anywhere, stops run off and silt dead in its tracks. A swale will naturally form on the up hill side not to mention vetiver's 12+ foot roots will help you store a bunch of water deep underground fairly quickly. Vetiver grass roots can establish quickly growing to 6 feet in under 6 months. So the benefits are: no digging; quick establishment and sequestration of runoff; non-invasive (it sends dense, fibrous, roots straight down so it won't harm plants around it) and it produces a a renewable mulch and fodder very quickly.

If your willing to dig as well as plant vetiver you can produce a highly effective swale in a short period of time.

Hope this was helpful!

James, that looks really interesting, but I don't think that will work in my area of choice, it being about a 200 day growing climate. It looks like a great grass for many tropical permaculture situations. Unless this grass also grows in colder regions....

I should have specified the situation. Annual rainfall 40+ inches, 1-10% slope, zone 6. Water is sufficient, over most four month periods, though there might be a month of no significant rain. When planting a new tree, it might need to have a way to maximize that water for a couple years. I do not want to have to irrigate a tree, I an planning several hundred, and irrigation would just be too much hassle.

This plant seems really good.
While it might not get to the 12ft dept as in tropical climate it still gets to 6ft in 6 months, after which it will die like a daikon radish aerating the soil and adding humus.
I think that the fact that it dies make it even better.
If it reseed, you wouldn't have to spend anymore money.
If it doesn't reseed, it may cost a little more money but it will not become invasive.

I am going to try and find a vendor source.

you could always get some large scale swales in now before planting while oyu still have room for machinary and then after planting simply hand dig a bunch of fish-=scale swales for each tree, i warn you though these can quickly become tiring



-updated farm thread

S Bengi wrote:This plant seems really good.
While it might not get to the 12ft dept as in tropical climate it still gets to 6ft in 6 months, after which it will die like a daikon radish aerating the soil and adding humus.
I think that the fact that it dies make it even better.
If it reseed, you wouldn't have to spend anymore money.
If it doesn't reseed, it may cost a little more money but it will not become invasive.

I am going to try and find a vendor source.

Vetiver can be grown in a greenhouse year round in most places. If you do this then you can easily replant if frost kills your vetiver because vetiver is propagated by transplanting a section of root and leaf. Simply grow some year round in a small green house and transplant them out when it warms up.