Cleaning seed

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Hoy's picture
Title: Member
Joined: 2009-12-15

Skulski wrote:

My current dilemma is how to deal with Hedysarum seeds... short of handling each and every one to remove the seed from the pod (which I'm currently doing).  Each seed is enclosed in its own close-fitting little shell; as the seeds are flat, it is hard to crush the seed pods without possibly damaging the seeds.  Bending the seed pod pops it open, but it's fussy to do on seed pods that are about 1/4" diameter.  If not for the Dept. of Agriculture requirement to remove all chaff and non-seed material in order to send seeds across the US border for the NARGS seedex, I wouldn't bother trying to remove the seed pod at all...  Any ideas?

If the pod break up into individual seed-containing pieces, each piece is in essence a nut and you don't shell a nut, do you? (I mean before sowing it - not eating it.)

When I clean seeds I use the same methods as suggested here - depending on type and volume and time, the paperbag method is my favorite even for very small seeds and fern spores.

Rogaland, Norway - with cool, often rainy summers  (29C max) and mild, often rainy winters (180 cm/year)!

Title: Member
Joined: 2009-12-04

I have used all of the methods mentioned usually in combination. For difficult seed such as Penstmon or Eriogonum I find the use of sieves, speeds the process along.
I use a variety of sieve sizes to sift or scalp off the course chaff (stems, dry leaves etc.) going down a size or two each time until the seed and remaining chaff are about the same size. I then rub the remaining chaff and seed between my hands to pulverise the chaff further.  Another sieving through a very fine sieve to remove the dust. Next I winnow the seed and remaining chaff in a light breeze or in front of a small fan.(keeping in mind that there comes a point of diminishing return) The last step is too pour the seed on to a tray and separate the seed from the waste with a small brush. I flick the seed to one corner and the waste to another.

For cactus fruit I squeeze the pulp and seed into a sizable container of lukewarm warm water and whisk the solution with a wire whisk to thin it out. Then I strain it through a kitchen stainer. The seed and remaining pulp is emptied onto a tray and spread out to dry. The dry residue can then be rubbed to release the seed. Last a final sifting with a fine sieve to get rid of the dust and any remaining dried residue.

From the High Desert Steppe
of the Great Basin and the Eastern
Escarpment of the Sierra Nevada Range
Located in Reno/Sparks,NV  zone 6-7
John P Weiser

Hendrix's picture
Title: Member
Joined: 2010-12-24

For me, Penstemon seed is the easiest species to clean.  I usually collect whole stems or, at least whole capsules, in white paper sandwich bags (so I can make sure all the seeds have been emptied from the bags when I process them).  I start with several cheap, thin, white paper plates with fluted edges and a common, large-mesh household strainer, pouring everything (seeds, capsules & stems) into the strainer without crushing anything.  Most of the seed will fall through that size mesh.  I set the seed aside on one of the paper plates.  If I need every possible seed, I then crush the capsules while they are still in the strainer with a double-rubber-gloved hand (yes, capsule pieces are sharp!).  Chaff and seed fall through the strainer onto a separate white paper plate and are set aside.  In a small-mesh strainer, such as a tea strainer, I pour in a small quantity of the nearly-pure seed and rub it vigorously against the mesh with my gloved hand, rubbing off the outer coating.  I repeat until the entire lot of this nearly-clean seed is rubbed.  If the seed is very small, it may fall through the mesh along with the powdery chaff and outer coating.  I catch it on a clean white paper plate.  With the outer coating rubbed off, Penstemon seed will roll freely when the paper plate is swirled.  Having a greater specific gravity than the powdery chaff, it tends to congregate and roll into the flutes at the edge of the plate where I gently brush it into another paper plate and then package it in a paper envelope.

If the seed is too large to go through the fine-mesh strainer, I dump the strainer contents (after rubbing) onto a paper plate and swirl the plate, blowing gently on any remaining pieces of chaff.  

The remaining seed and crushed capsules that I had set aside on the other paper plate are processed similarly, the only difference being that I may have to use an intermediate strainer to get more of the crushed capsules removed before I do the final seed rubbing and plate-swirling.

I have used this method on Penstemon seed for about 12 years.  Rubbing off the outer coating does not adversely affect the viability or length of storage of the seed as I have often germinated seed cleaned in this fashion that was up to 8 years old.

Jane Hendrix
Mountain View Experimental Gardens
Peak 7-Breckenridge, Colorado USA.
Elev: 10,000 feet
Zone 4 &



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