This past fall I heard a talk about improved germination of seeds when they’re soaked in an extract or “tea” made of worm castings (notes on the talk are here). I tried my own experiment which I posted recently. The results, while in favor of the castings-soaked seeds, were inconclusive. So now I and am now trying again with tomato seeds that I’m sprouting indoors for spring. Here’s how it has gone so far:
Forty cherry tomato seeds were divided into two groups. One group of 20 is soaking in dechlorinated water. The other 20 are soaking in an extract of worm castings and dechlorinated water. They were left to soak for 3 hours.
The seeds were planted in peat moss — two per cell. They are at room temperature — about 68 degrees F. At this temperature they should germinate in a week or so.
Update: February 9, 2014. By now, all of the tomato seeds that are going to sprout have done so. These seeds sprouted so well that the results are inconclusive. The germination rates were about even with 18/20 seeds soaked in water sprouted and 17/20 seeds soaked in vermicompost tea sprouted. The next step will be to use vermicompost when I pot up these plants and see if it improves growth.
Update: March 5, 2014. To continue the experiment, we are potting up the strongest of the seedlings in Miracle Grow Potting Mix. The seedlings started in vermicompost tea will also have worm castings added to the potting soil.
The largest 5 plants of each group were potted up at the beginning of March. The 5 non-vermicompost seedlings on the left were planted into 100% Miracle Grow Potting Soil. The 5 from seeds that were soaked in vermicompost tea on the right are planted in 20% worm castings and 80% Miracle Grow Potting Soil.
Color: The five on the left planted in 100 percent Miracle Grow Potting Mix have some yellowing in the leaves. The 5 on the left planted in 20 percent vermicompost and 80 percent Miracle Grow Potting Mix have darker green leaves. The next step will be to pot these up again and place them outdoors when weather in the Vancouver area permits.
Update: March 26, 2014. After 3 weeks side by side under daytime grow lights there has been lots of growth. The 5 plants on the left were potted in 100 percent Miracle Grow Potting Mix. The 5 on the right were in potted in 80 percent Miracle Grow Potting Mix and 20 percent vermicompost.
Size: The plants in 100 percent Miracle Grow Potting Mix have some larger leaves. The plants in 20 percent vermicompost and 80 percent Miracle Grow are taller.
April 10: The plants in vermicompost are on the left now. I’ve moved them for repotting since the seedlings were getting to tall for their starter pots. Observation: The plants are roughly the same size at this point. The seedlings in vermicompost are still greener.
April 10: The tomato plants have been potted up into the same Miracle Grow Potting Mix as they started in. The plants on the left are still in 20 percent vermicompost.
In mid April, the tomato seedlings have been moved outdoors into a cold frame with a glass top and door (not shown here.)They are intermixed, but have labels showing their soil composition.
Potted up again in early May – the strongest 4 of each were potted up for the rest of the season. The plants on the left are in vermicompost, on the right are in Miracle Grow Potting Soil.