Tuesday, March 4

March 2008 - Seed Ball Project

Easter comes early this year, and I thought a nice gift to my gardener friends would be some wildflower seed balls. These little balls of clay, compost, and seed can be placed on the soil surface to germinate, not requiring planting into the ground. The clay helps deter pests from stealing the seed and retains moisture.

Commercial sources of these include "Seedballz" which sell for about $6 for a package of 8 at Amazon. These commercial varieties are a bit larger than what I'm about to show, but I found the smaller version is easier to make by hand.

My original plans came from Path To Freedom. I've modified their recipe slightly.

You'll need:
  • dry terracotta clay powder or moist clay
  • dry composted manure or compost
  • seeds
The basic recipe I use is:
6 parts clay
4 parts compost
1 part seed

If you cannot find terracotta clay powder, you can use moist clay that has been air dried (not kiln fired!) and crushed. I found a cheese grater and mortar/pestle the best tools to dry and pulverize the clay in an efficient manner. Strain out any large chunks and crush again (a kitchen sieve works fine).

Using the directions from Path To Freedom: mix the seed and compost together, add the clay, mist water with a spray bottle while stirring to get it to clump together. Do not add too much water, it will be difficult to form balls with too much moisture in the mix. Pinch off a small portion of the mixture and roll into a ball. I find it easiest (and cleanest) to use plasticized gardening gloves for this step, keeping most of the clay off my hands. Let the seed balls dry for a couple days, protecting them from curious children and pets.

Plant about 1 seed ball per square foot.

For a spring garden gift, consider packaging a handful of seed balls in a small flowerpot, perhaps with a plant marker and twine bow. Include a card with instructions and descriptions of the seed varieties. I've chosen to make a shady blend and a sunny blend.

Be sure to check with your local university extension office for native plant species to use in your seed balls.

How much did it cost me?

compost: free
clay: $1 from potter friend (can purchase 50 lbs for about $23)
seed: 1/2 cup wildflower seed mix (no filler) $13 from local garden center. (makes 250 or 300 balls)
pots: $0.50 each
twine: $0.05 (on hand)
seed markers: $0.50 each at local garden center
instruction card: $0.05 (printed on index cards)

So each gift will cost about $3 total, plus my time. The seed balls alone will cost about $14 total (clay and seed), or about $0.05 each.