Subject: Woody Legumes and Swales

From: [email-masked]
Date: Sat, 11 Oct 1997 11:34:46 -0400 (EDT)

A while back someone asked about broadcasting woody legumes into swales,
specificially, as I recall, about species recommendations.

I passed at the time, but since no good response came through (or I missed
it), I'll try to shed some light on considerations.

First, most woody legumes require some sort of pregermination treatment to
germinate.  Just throwing the seed around may not sufficie.  Seeds of Woody
Plants... from GPO covers most of the commonly grown leguminous (and other)
trees in the US and is a basic reference for any North American
permaculturist.  Also local arboreta may well have data.

I've never seen this published, but sometimes peregermination treatments can
be avoided by planting fresh seed before it fully dries.  Of course if it
then dries in the swale, you are back to needing the treatment.  I've seen
this work a few time and have heard propagation experts at the Arnold
Arboretum (Harvard's arboretum) mention this.  

Finally, I am skeptical that IN the swale is the best place for most woody
legumes which, as a group, tend to like drought but not flooding.  There are
minor species of Robinia, including some native to Texas if my aging memory
is not playing tricks on me again today, that are water loving.  Even R.
psuedoacacia, though it likes well drained soil, tolerates a bit of flooding.
 However if you look at its location on river banks, it is always on the
outside of the bend where the bank is high and steep, not on the interior of
the curve, low and gradual slope, where the willows grow and further back the
populus spp.  There is also a gleditisia aquatica that, as one would surmise,
likes wet or at least tolerates it.  However there is some serious question
about whether gletisia fixes N.

Interestingly, I've seen alnus spp, the same as grow in swamps, in places
where water supply is very minimal.  They are great N fixers and might be a
better choice for inside the swale.  They are soft wooded and can easily be
slashed for coarse, n-rich mulch.  The jujube genus (ziziphus or something
like that) also is drought tolerant And flood tolerant, can produce thorny
branches quite useful in fencing (a chicken wire tree) and of course has
tasty fruit.  I think these would be happy in the area mentioned, though it
really depends on the frequency with which the swales are flooded.  Mostly,
I'd consider planting the legumes on the berm, not in the swale.

This will be my last detailed response to this list for several months as our
onlin e permaculture design course starts tomorrow and I will give it all the
online attention possible.   

If anyone is interested in a permaculture training in Paraguay in Sept/Oct,
1998, they should email me privately.

Have fun, guys.  I'll be lurking.

For Mother Earth, Dan Hemenway, Yankee Permaculture Publications (since
1982), Elfin Permaculture workshops, lectures, Permaculture Design Courses,
consulting and permaculture designs (since 1981), and now correspondence
courses via email.  Next starts in Oct. 1997. Internships available.
Copyright, 1997, Dan & Cynthia Hemenway, P.O. Box 52, Sparr FL 32192 USA
 [email-masked]  

We don't have time to rush.