Aug. 16 column: Compost tea

Ryan Herring gives a compost tea demonstration at NW Seed & Pet.

Here’s a link to my column in today’s edition of The Spokesman-Review: Compost tea seems worthy of a toast.

This one is about the benefits of using compost tea and compost extract. And let me tell you, it was hard to say everything I needed to say in 600 words! Thank heavens for this blog because I can give you additional information without any worry regarding my word count.

On Aug. 8th, I went to a compost tea demonstration given by Master Composter and WSU/Spokane County Master Gardener Ryan Herring at Northwest Seed & Pet. The talk was very informative and gave me a lot of ideas.

Here is the additional information I learned from Ryan:

Close-up of Ryan’s aerator set-up.

1. In my column, I described the supplies needed for a simple system but didn’t have room to discuss Ryan’s set-up for the aerator. He uses a large pump and attaches it, via plastic tubing, to PVC pipes. “My air-lift system pulls water through the 1″ PVC pipes and provides two times the air because it is both pulling the water up through the pipe and the water breaks the surface tension in the bucket because the pipe is a couple of inches above the surface of the water.” (see photo above)

Also, you can get as fancy as you want if money is no object because there are also commercially-produced compost tea systems available. I primarily focused on a simple system.

2. “Compost needs to be well-broken-down and have a lot of biology in it.” (so be sure to use good-quality compost!) He mentioned how you can buy compost that has been produced in this area, but that it’s better to make your own because then you know what’s in it.

3. Ryan explained how some plants do better with different types of teas. Most Brassicas (crops like broccoli, cabbage and cauliflower) prefer tea with a lot of bacteria in it. Most other veggies and grasses do better with tea that has a moderate amount of bacterial activity in it. Other plants (such as berries, deciduous and coniferous trees) prefer tea with a lot of fungal activity in it.

To create a more bacterial compost tea, you would add a microbe “food” like fish emulsion or worm castings. To create one that is more fungal, add in ground oatmeal, powdered malt or soybean meal. Ryan told me that fungus likes a dark area to grow in so once he’s added the microbe food and catalyst to the compost, he moves it to his basement for 4 days. He mentioned how you’ll see white fuzzy growth in the compost, which is the fungal activity so don’t freak out!

Ryan also pointed out that Eastern Washington soil tends to be higher in bacteria than fungi, so he feels our goal should be to make compost tea with more fungal growth.

Last but not least, there are some businesses that sell packaged compost tea but it’s important to know when it was made since, as Ryan put it, “it has a very short shelf life when it’s been sealed in a container.”