Herb and seed cleaning

By | Friday, March 04, 2011 6 comments

I like to grow and dry my own herbs. No, not that kind of herb. Yes, I live in Oakland, but no, really, not that kind of herb. I'm also a seed saver. No, not those seeds. I am a proud member of the Seed Savers Exchange. I really like letting some of my vegetables go to seed and saving them to replant the next year. The thing that has held me back in doing that more often is the effort involved in cleaning the herbs and seeds.

I recalled seeing something in Mother Earth News a while back for threshing seeds. But when I looked for it, I couldn't find it anywhere. Also, I couldn't remember if it was an article or an advertisement for a product. I searched online for seed cleaning products and herb cleaning tools, but I couldn't find anything appropriate for the small home gardener. So I decided to make my own.

Here then for your enjoyment and ridicule is the step-by-step photo instructions for Andrew's handy-dandy herb and seed cleaner (tm).

  • 4 1x4 lumber
  • Hardware cloth in three grades (your choice - I used 1/4" for the top layer, 1/8" for the middle, and window screen (1/8"x1/16") for the lowest layer.)
  • Screws (I used 1.25" coarse thread drywall screws, because that was the most convenient thing that I had laying around. Virtually any kind of screw will do.)
  • Saw, drill with bits and countersink, metal snips, screw driver (or bit for drill), staple gun

I measured and sawed my 1x4's into 2 17" lengths and 2 13" lengths for each level in the box. These sizes were convenient for me in relation to the pieces of hardware cloth and the size of the box I wanted. You can make them larger or smaller as you choose.

Here the pieces are laid out prior to assembly of one level of the box.

The pine 1x4's were very soft, so I was concerned about the wood splitting.

I pre-drilled my holes and counter-sank them to decrease the chances of the screws splitting the wood, especially since they were going into the edges of the pieces.

How did I ever live without an electric screwdriver? I used 4 1.25" coarse thread drywall screws on each side. Probably overkill.

One assembled level of the cleaner box.

I measured and cut my 3 different grades of hardware cloth

Then stapled them to wooden box (one per level.)

The three levels of cleaner frames with screens in the bottom of each level.

Looking down into the finished 3-levels of the cleaner from above.

For large seeds/herbs, I will want to catch any duff that falls out the bottom (for discard.) For small seeds and herbs, that which falls through is the end-product. I made another frame (this time with a 1x2 because I ran out of 1x4's - doh!) I took an Amazon.com box, covered the bottom with aluminum foil, and placed the frame in the bottom. This becomes the lowest level catch basin. Any kind of plastic bin would have worked fine. I am planning on upgrading this (see below.)

The cleaner frames set in the box

Carrot seeds dropped into the top

Bits of carrot flower stem caught by the grossest screen

More trapped in the next level

Seeds end up in the finest screen, with duff left in the bottom box.

I'm really happy with how this turned out. The whole thing cost less than $15, and I can customize it as I need, adding or removing levels, or even swapping out grades of hardware cloth if I find that the grades I used aren't ideal. I am planning on getting rid of the cardboard box on the bottom by slapping a sheet of Masonite on the bottom of my lowest frame. Also, I want to put a piece or two of metal strapping on each edge of each layer (except the top) that will hold the frames together in a stack (currently they sit on top of each other through friction.) I'll keep you posted.

Suggestions for improvements are always welcome! Comment below!

I have made some of the improvements I mentioned above. See my blog entry for the Improved Seed Cleaner for more.
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  1. Your herb and seed cleaning box is sheer genius. Countersinking the screws, now that's attention to detail. I look forward to building my own, thanks for sharing this great tool.

  2. Thanks Tom! I have added some improvements http://andrewsigal.blogspot.com/2011/03/improved-seed-cleaner.html. Let me know how your's turns out and if you find ways to make it even better!

  3. Hi Andrew, this is great! I work with a youth gardening program and we're hoping to make seed saving boxes. This is such a wonderful design and helpful post! Would you be able to share what grades of hardware cloth you're using and if you would make any adjustments? Most of the school grow a variety of crops (from large seeded things like beans to the fine seeded crops like carrots) so I just want to be sure it's effective for a wide range of crops. Thanks in advance!

    1. Hi Sahar;

      Thank you so much! One comment like yours makes the whole Blog worthwhile :-) For the hardware cloth I used 1/4" for the top layer, 1/8" for the middle, and window screen (1/8" x 1/16") for the lowest layer. So far it has worked out great for everything from scarlet runner beans to carrot seeds, as well as dried mint, basil, and thyme.

      Note: I have added the dimensions of the hardware cloth to the post.

      Also, when not in use I cover it with a plastic top that I re-purposed from a storage box - otherwise I find that junk falls into the cleaner, requiring extra effort before each use. The modifications that I described in http://andrewsigal.blogspot.com/2011/03/improved-seed-cleaner.html have held up great.

      I'd love to hear how your students boxes turn out, and if you come up with any additions or enhancements.


  4. Thanks for showing us how to do something so useful. The pictures are very good too. I will share it with my friends that are as fond of DIY as me :)

  5. Thank you for posting this, and the photos are great. I'm a visual learner so this really helped me. Also read your update thank you


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