Using Worm Castings for Cannabis Growing

Using Worm Castings for Cannabis Growing 4Using Worm Castings for Cannabis Growing

Question: I have a huge bag of worm castings and want to know what’s the best way to give them to my plants. They are just about ready to flower. Should I top dress with it? Brew a tea? Can I dissolve it in water and make a foliar tea?

Jay Kitchen and Uncle Tweezy: Don’t make a nutrient tea from worm castings and use it on your marijuana plants if they have flowers—you don’t want your pot to taste like worm poop. If you’ve transplanted already then you have fresh soil so you don’t want to throw off the balance of the soil too much by adding worm castings right now. But you can add a layer of worm castings during week two or week three of flowering. That’s about the latest we would do it. Because you’ve got to remember that worm castings are time released. So they’re going to take some time before they break down in your soil. It usually takes a week. When you grow in soil the additions you give to your plants usually don’t affect them until about a week later because the soil buffers everything. Worm castings are a great trace element, but you can only use them through week two and that’s really it.


If your flowers are not like little cotton balls, like they’re still in transition and starting to stretch then making a nutrient tea with the worm castings and using it on them isn’t a bad idea, but once they start cotton balling it’s time to stop. You have your own worm castings so you can use that. If you’re going to make that tea you just need a teaspoon to a gallon. You ain’t got to put a lot—less is more. Remember it’s a time release trace element nutrient as well. Use a nice fresh bottle of worm water, let the castings settle for a day or two then put it all in your spray bottle and foliar feed your plants a couple of times.



For those of you who don’t have a bag of castings there’s a product out that you can called Vierra’s worm castings. That shit looks like lemon aid it’s so clear. They ferment it at real cold temperatures. Remember you can hit your plants with worm castings in week two but after that you should just let it ride—no spraying after week two once they’re in flowering.

All of our love from The Kitchen! Stay lifted, Jay Kitchen and Uncle Tweezy uptowngrowlab.net

To answer all your cultivation questions we’ve teamed-up with experts Jay Kitchen and Uncle Tweezy, authors of The Kitchen presented by Uptowngrowlab—an oversized, hard-covered, coffee table book that’s 50% grow guide, 50% adventure story and 100% awesome.



6 Responses to “Using Worm Castings for Cannabis Growing”

  1. The Worm Whisperer

    I have always used worm castings in conjuction w my worm tea. Outdoor swimming I use the combo above along with rabbit manure and this keeps me bug free. But worm tea does not alter taste in fact you can spray directly on flowers and fruit. I worm tea it up on flowers-buds till last week.

  2. Eddie P

    you guys sound like amateurs suggesting it would make the weed taste like worm poop in any scenario. and how the hell is it gonna throw off the soil balance adding a rich organic nutrient that the soil will absorb itself? its not miracle grow it will balance itself as long as you dont put a crazy amount in each plant, what wouldve been the difference if you already wouldve had it mixed in the soil during or before transplanting? haha and you said it takes a week for it to affect the plant so it cant possibly unbalance it because the soil is slowly taking the nutrients and the plant naturally takes what it needs as long as you dont put more than you normally would. you guys sound like youve grown like twice and decided to make a website

  3. Koma

    Wow… Telling people to not use worm castings in flower? Really? This is why i started my own website… This is why it was so hard to start growing… People like you who crave attention so much you make posts abput stuff you have no clue about… Sad really… KOMAGROWS.COM come learn something

  4. Patrick Perry

    My composting worms produce only 8 cubic yards of organic vermicast yearly that is harvested each spring.

    Rapid production of worm castings from low nutrient feedstocks does not make quality castings.

    Shredded maple leaves, alfalfa, cornmeal, oatmeal and barley produce large healthy worms for sale and the resulting castings out produce all other castings growers have compared them with.

    Check what goes into your worm castings if you want high quality organic castings that maximize production!

    Our company is about to release 20,000,000 pounds of high quality Amazing Castings that are from 3 acres of fishing bait worm beds 24 inches deep. Greenhouses that have done preliminary tests say they have not found anything comparable.

  5. marcus

    i was gona chime in with some criticism about this article, but apparently others have responded with the same feeling. this article not accurate.

  6. boge

    i find that using watering with worm castings can change the soil ph before it stabilizes again.
    some plants don’t like that, mainly acid loving plants don’t like the higher pH. results in dropping leaves

    topdressing with worm castings and watering those in over time might be a more gentle approach.
    but cannabis tolerates pH 7.5 so no problem expected

    or get some pH paper and test, plants don’t like pH shock because it messes up their nutrient uptake. some plants adapt easily, some don’t.

    any peat based potting soil tends to become more acidic with time, so old well established plants might get a ph shock if drenched with

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