You want your weed plants to be happy and healthy (and you’d like to believe they feel the same way about you). You water them, give them nutrients (not too much), and plenty of fertilizer. But have you ever considered asking them, “care for some tea?” (British accent optional). Specifically, we’re talking about compost tea. Many growers are starting to use compost tea on their weed plants, and each one has their own preferred recipe. Here at WikiLeaf, we went to one of the best for his take. Benjamin Short is head grower of Puffin Farm. Their bud grown from living soil using compost tea has won awards from the High Times Cannabis Cup, the Seattle Sun Cup, and the Terp Festival. Benjamin generously agreed to share how Puffin Farm makes their compost tea, some advice for both farm and home growers, and the best ways to water with your compost tea. But first, let’s dig into what exactly we’re talking about.
What is Compost Tea?
Compost tea is the liquid version of the microorganism-rich, decomposed organic materials that you add to your plant’s soil to keep them thriving.
Why Use Compost Tea?
According to Benjamin, who also assisted in compost research studies at Oregon State University, compost tea filters down to the root system and adds to the microbial life in the soil.
“The microbes will kind of get attracted to the root zone and feed off [sugars] that the roots are releasing, and then in turn they'll break down nutrients in the soil, making them more available to feed into the roots, and also protect them from…powdery mildew, damping off, and other soil-borne diseases.”
Compost tea also helps with disease suppression when added to foliar feeding (spraying nutrients directly onto the leaves).
How to Make Compost Tea
Compost tea is relatively cheap and easy to make. Recipes vary from specific ratios of ingredients to dumping store bought compost into a bucket of water, giving it a stir, and calling yourself done. As Puffin Farm’s award-winning flower is known for its potent terpene content, we’re sharing that recipe below along with the reasons for each ingredient. A good rule of thumb is to go for a 1:20 to 1:40 ratio of compost to water. Here we’re going with 1:40.
Puffin Farm’s Compost Tea Recipe (with ratios for home growers):
- 200 Gallons of Warm Water (40 parts) — “[Temperature-wise] around 70 to 80 degrees Fahrenheit is ideal…you don’t want it too cool because microbes won’t grow…and too much above 80-85 degrees it’ll get all funky and grow things you don’t want in there…”
- 5 Gallons (1 Part) Worm Compost — Store bought is fine, but worm compost contains more micronutrients.
- 5 Gallons (1 Part) Alfalfa — “It has naturally occurring trichotonol, which is a growth stimulant. That helps a lot, especially with younger plants, with getting roots established and getting them going.”
- ½ Gallon (1/10th Part) Rock Dust — “It’s not necessary, but it adds micronutrients and and...there's sort of a little bit of everything in rock dust.”
- 4 Cups (1/20th Parts) Humic Acid — “It’s naturally occurring in soil…but we add a concentrated Humic acid, which is pretty high in potassium…”
- 4 Cups (1/20th Parts) Kelp — The kelp adds “various natural growth promoters and other good stuff...a lot of micronutrients and potassium.”
Note: Many recipes will call for using molasses, but Benjamin recommends against this. “From the research I've seen, it can cause some undesirable bacteria like salmonella and E coli to grow…adds to the growth of plant pathogens, and decreases the amount of beneficial bacteria.”
Step 1: Get a Container to Serve as Your Brewer
While Puffin Farms uses a 250 gallon brewer to make their compost tea, a home grower can use something as small as a five gallon bucket.
Step 2: Add in Your Water and Get it Circulating and Aerating
Microbes love oxygen, and circulating/aerating means they’re happy, fed, and reproducing. There are plenty of aerator/circulator options, from this 10 gallon compost tea brewer to this $30 clip on aerator. YouTube also has plenty of DIY compost tea brewer guides.
Step 3: Mix up Your Compost
Step 4: Dunk Your Bag into the Circulating Water
Make sure to keep the temp around 70-80 degrees then let it “brew” for about 48 to 72 hours. If you don’t have an automatic circulator or aerator, at minimum you should give it a generous stir with a stick every morning and evening.
Step 5: It’s Tea Time!
How to Water Your Plants with Compost Tea
After your tea is brewed, there will be a layer of sediment on the bottom of your container. This isn’t an issue if you’re pouring your compost tea directly onto the plants. However, sediment can clog up drip irrigation pipes or sprayers. For that, Benjamin recommends tapping your feed hose into the middle of the container. When watering with compost tea,
“It's especially beneficial in the early stages when your cannabis plants are getting established…But most of the season we'll hit them like once a week with compost tea. Generally, the more the better.”
Puffin Farm also foliar feeds their plants in the early stages to help prevent disease, but tapers off as the plants mature and stops once they’re close to flowering.
It’s (Compost) Tea Time
If you’re looking for a relatively cheap and easy way to ensure healthier and more productive plants, offer them some compost tea. The beneficial microorganisms will help protect your plants from soil-based diseases and feed more bioavailable nutrients into the roots, which will boost trichome production. So, brew up a cup! It’s only polite when you invite a plant into your home. Thanks to Benjamin Short for sharing his knowledge with WikiLeaf!
Frequently Asked Questions
How Long Does it Take to Make Compost Tea?
It takes a minimum of 24 hours, but it’s recommended to let it steep for 48-72 hours (2-3 days).
How Do You Make Compost Tea from Kitchen Waste?
You’ll need to compost the kitchen waste first by putting it into a bucket with some soil and worms to break down the organic matter and establish a community of healthy microorganisms.
Can Compost Tea Burn Plants?
No. Compost tea doesn’t have high enough nutrient levels to cause nutrient burn.
How Do You Make Compost Tea for Houseplants?
You’d make it in the same way as you would for outdoor plants.