Seed Balls 2.0

It’s no secret that my recent introduction to the “seed balls” concept really has me fired up! While I’ve alluded to the fact that this goes beyond a simple interest in seed balls themselves (as cool as I think they are) – I have yet to explain where my kooky brain has gone from there. That’s what we’re going to look at today!

As someone who has had a lot of frustrating experiences with trying to get seedlings started (from seed) in the garden – just the idea of protecting the seeds, providing some starter nutrition for the seedlings, and helping to establish a community of beneficial microbes in the root zone caught my interest right off the bat. But I then started thinking of ways to go even further with it.

What if I mixed in absorbent, lightweight materials like paper pulp? What about other natural “fertilizers” and amendments? What if I played around with the proportions of materials to see if I could create some sort of effective, bio-active growth medium for plants? What about “worm food balls” – i.e. something like living material + paper pulp + rock dust + chick starter feed (maybe some cornstarch as a binding agent)?

It just so happens that my wife’s co-workers collect cardboard coffee trays for me – and she brings stacks of them home periodically. Normally, I simply rip them up and use them as a bedding material. What’s funny is that I’ve never previously thought of actually turning them into a paper pulp – very surprising when I think about it, since the pulp would be perfect for “homemade manure” and just generally as an optimized c-rich material for my vermicomposting systems!

It wasn’t until I started reading up on seed balls – and was particularly inspired by this site: – that it hit me!

I still wasn’t sure how readily I could pulp up the coffee trays (my hunch was that it would be incredibly time-intensive) – but I knew I had to at least give it a try! So I filled a bucket with hot water, put in a stack of the trays, threw on some dish gloves and went to work!

Long-story-short, I was pleasantly surprised with the results! I found that the trays broke up very easily in the hot water, and in no time I ended up with a nice looking slurry of paper pulp. Luckily, I just happened to have a handy dandy tray from my WF-360 bin on hand – so I even had a great way to speed up the drying process. My goal wasn’t/isn’t to completely dry out the material – but simply to get rid of excess moisture so it’s not dripping wet.

With my new pulp ready to go, I decided it was time to mix up my first batch of “seed ball” mix. Since I was in fact planning to make some actual seed balls I decided to go with the recommended 5 parts vermicompost and 1 part dry clay (purchased from a local pottery supply store). BUT, I also included 2 (or was it 3? – LOL) parts paper pulp.

Last weekend, I had some fun with my kids making up various types of seed balls so I can test them out. We used sunflower seeds, bush beans, and tomato seeds. I also coated some sunflower seeds with the paper pulp alone, so I can do some comparisons (i.e. see if the seed ball mix provides any additional benefits).

As you can see in the first image (and image below), I also created some homemade seed plugs with the mix.

Every spring – due to those aforementioned issues with getting plants to grow directly from seed in my gardens – invariably I end up starting most of my plants in peat pellets, newspaper pots (with potting soil) etc. While I am very happy that I end up with a lot more healthy, vigorous plants in the gardens this way, it tends to cost a fair bit for all the supplies, and takes up a lot of my time.

Now – I think I have a way of creating seedling starter plugs that are superior to traditional peat pellets (etc), and less expensive (of course this is in large part due to the fact that I have plenty of my own vermicompost)!

I will likely need to play around with the ratios of various materials in order to find the “perfect” mix. I want something that will hold moisture really well, but not so dense that the roots will have trouble growing through it. As such, I will likely up the proportion of paper pulp in my next batch.

NOTE: Blake recommends keeping seed balls to a size not much bigger than a dime or marble (i.e. smaller than you might imagine). I myself will be creating some variations that are definitely a fair bit bigger than that – but I’ll more than likely waiting for them to dry out a fair bit before adding the seeds – you definitely don’t want to risk stimulating the germination process!

In case you are wondering about the larger, darker balls (stop your snickering, John W!) in the first image – they are not actually seed balls at all. I simply mixed some paper pulp with some vermicompost for those ones. What’s cool is they are super-lightweight and actually hold together beautifully! This may not come as a surprise to anyone who has accidentally let wet vermicompost dry out completely. My nickname for this material is “vermicrete” – and it’s well deserved!

I still think there may be some benefits to adding at least a little clay since you end up with with a smoother material, and likely seed balls that hold together better.

Once all my various seed balls (and variations) were dry (I ‘cheated’ a bit by blowing air from a heat fan at them), I tested some out for re-hydration. Even though they had a rock-like feel (albeit lightweight rock! lol), I was amazed to see how readily they wicked up water and developed a nice soft consistency!

Anyway – LOTS more testing ahead (will be making up a new batch of mix this afternoon in fact) – and plenty more updates here I’m sure. But I am very excited with the results so far!

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    • John W.
    • February 21, 2014


  1. Great idea to use paper pulp as an ingredient in seed bombs! I was thinking along similar lines myself, so I’m glad to hear that your experiment worked so well.

    • John Duffy
    • February 21, 2014

    This might be a great eco-friendly project for some elementary school kids. I will have to try the hot water method to break down the drink trays.

  2. I’m wondering what the clay mix is adding? For the plants I can’t see much / any benefit?
    Is it just to increase stickiness?

    • Travis
    • February 22, 2014

    Good deal! Keep up the good work.

    • LS
    • March 3, 2014

    so are you going to plant the seed ball directly in the ground? would you need to wet them first?

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