Back in November of 2018 I started an indoor garden in my basement. I had brought in a couple of things to over winter from our garden. Swiss chard and collard greens. We also started some broccoli, carrots and chamomile from a kit the kids had. We hoped to be able to supplement our meals through the winter with a little home grown roughage. Now this is not my first indoor garden, not by a long shot. But I've never had any issues like what I'm going to tell you about.
Our Basement Garden
Shortly after things got rolling along with our little garden. Cannabis was legalized to where anyone 21 years of age can grow 12 plants here in Michigan. This has been so liberating for so many people! I picked up some clones from a friend. He gave me five of them. They were small and had just been rooted. I've grown in the past but this time it was nice to feel like I didn't need to hide it anymore.
I should step back here and also explain that a year earlier we purchased some Okinawan sweet potato starts from a nursery online. And also, in the same year I had built my wife an aquaponics system in our living room. Where we grew those sweet potatoes among other things. Then we decided to move the grow tent to the basement. I then converted it all to a soil based system. The sweet potatoes always had problems that would come and go. I could never figure out what was happening. In the end I just thought aquaponics wasn't for us so we went back to soil to keep it simple. No pumps to run!
The Trouble Begins
Almost immediately after introducing the cannabis plants I noticed little black flies. I wasn't sure if they had come from the crawl space? Or if they were fruit flies? I figured they would go away. But oh no, that was not the case at all!
After a week or two they were everywhere. I had the sweet potatoes on a wire rack with a light above them. They had recovered nicely from the transplant shock and new leaf growth was happening. Though one could see that they definitely had something wrong with the older leaves. Almost like some kind of deficiency. The cannabis plants were on the shelf below, also under a light. Little gnats everywhere.
I did some research on these gnats, as things were really starting to get out of control. Lo and behold, Fungus Gnats! I immediately started researching what I should do. And let me tell you, there are people out there doing things to get rid of fungus gnats that I would never dare to put on plants I later planned to ingest. But there are a couple of things that I ended up doing that worked well and I felt that I wasn't doing anything that would effect our health.
The Fungus Gnat Fix
People are purchasing something called Gnat Nix. And it looks like a really good product. It's apparently 100% recycled glass. And I've seen prices as high as $50.00 for 1.5 cubic foot bag! But I'm a cheap old bastard so I had to find something else. I've used diatomaceous earth or “DE” before in the garden for squash bugs with good success. But any DE you can purchase in the store is in a fine powder form. It too can have a pretty high price tag at $12.00 for two pounds of the powdered stuff! I wanted something more granular to put in my pots.
Here's a little secret, I found “Safe T Oil Absorbent” from True value hardware or Floor Dry both made by EP Minerals is 100% diatomaceous earth in a more granular form. The great thing is this stuff can be purchased for less than $10.00 a 40 lb. bag. We use this at my work for hydraulic oil and other spills, but it can easily be found at auto parts stores. Make sure whatever you purchase that it says 100% diatomaceous earth or you could end up buying a 40 lb bag of clay instead. Don't get “Oil dry” its just a form of clay like kitty litter. And please don't blame me if you screw it up, you've been warned. I know, because I've done it.
I spread the DE in the tops of all my pots about 1/2” deep. The fungus gnats lay eggs below the soil line. They hatch and feed on fungus in the soil and your plant's roots for a time. Then they pupate and crawl up and out of the soil. Just to fly around and be annoying and possibly spread fungus type problems onto your plant's leaves. In large numbers they can be devastating to your plants. Action must be taken. Also, please note that DE contains silica. So don't breath in any of the dust!
After applying the DE to the soil I could rest assured that would take care of anything emerging from the pots. But with the numbers of gnats I had flying around I knew I needed to do more. The soil by now was teaming with gnat larva and destroying my plant's roots. I lifted one of the plants and instead of nice white roots we had sick looking brown roots. I talked to the guy that I got the clones from. I asked if he had Gnat problems. He said no, but suggested I go to one of our local grow shops. He said they would have anything I may need to get rid of them.
“All my problems will go away?”
So I went down to the grow shop and asked the guy at the counter what they had to get rid of fungus gnats. He and his cohorts were eating their lunch. He said and I quote “You need T-drops Man.” Everyone chuckled a little when he said it. One of the guys looked up from his chili cheese fries and yelled “Tee Drops!” He gave me a sample of the stuff and said, “Put two drops of this in a gallon of water and all your problems will go away.” I said “Well that's amazing! All of my problems will go away?” I then asked, “Whats in it?” He told me it's proprietary, but that it's some kind of fungus that kills gnat larva. I also picked up some yellow sticky traps to take care of what was flying around my grow area and to monitor for them after they were gone.
I avoid grow shops like the plague. I don't have anything against them. But I don't want to spend any more money if I don't have to. They have helped me in the past, and I'm sure I will walk into another before too long. Every time I've gone into one, it seems like the products they sell are just over priced diluted relatives of the real thing with fancy labels. And when asked whats in a product you get a partial story and then “It's proprietary.” Instead of something you can get at a nursery supply or feed store where they disclose whats in the packages fully, with at times a lower cost. Just be aware that usually you can save some money using standard gardening products whether growing indoors or out.
In the case of T-drops, they should be disclosing what the hell they are putting in their product for the person about to put it on their garden! They “CX Horticulture” claims their product contains a “predatory fungus specifically evolved to eat gnat larva” That just doesn't sound right to me. So the sample bottle the guys at the shop gave me has been sitting there for God knows how long. And the fungus or spores that are in liquid suspension are still alive? It's too bad they don't just say what it is. Then they claim its safe for “plants, pets and people.” The guys at the shop gave me a sample. But the 20ml bottle costs around $40.00. Just tell me what's in it is so I can decide for myself if I want to use it and pay that kind of money for it.
Another Gnat Fix
I went home disturbed by what might be in T-drops that works so well but is also proprietary. So I researched some more. I couldn't find any predatory gnat fungus out there. But I did find something that isn't to horrible, bacillus thuringiensis israelensis. Yup good ole' BT. Now BT is approved for organic farming and there have been extensive studies on it's safety when humans come into contact with it. I have never used anything like it on my gardens. But I decided to keep looking into this. Just to see if I thought it would be something I would consider.
There are other products out on the market that clearly state what is in them that control fungus gnats. These are regulated by the EPA. Two of those are Microbe-lift BMC and the other is Mosquito bits or mosquito dunks. Both contain BT. I could do a whole post just about BT at this point from the research I did. I decided to use it as a natural control for the gnats. I encourage you all to research bacillus thuringiensis israelensis and decide for yourself if you want to include it in your gardening arsenal.
I ended up purchasing the microbe-lift BMT for under $18.00 and It worked wonderfully for the gnats. I could see new white root growth within days. Unfortunately this was not the end of my pest woes. I had another problem that had been brewing for a year right in front of me. I had now after defeating the gnats put some of the sweet potato plants along with the larger cannabis plants right into the grow tent with everything else.
Hidden In Plain Sight
I discovered shortly after, much to my chagrin that my garden had Thrips! They had been infesting those sweet potatoes all along. Probably straight from the nursery I purchased them from. The BT only effects certain insects mosquitoes, fungus gnats and not much else. I found that anything that gets rid of Thrips, I'm really not willing to put on my food or herb. All of the plants had thrips crawling all over them. These guys lay there eggs right in the plant leaf and stem tissues. I was devastated, but there really wasn't anything else to do. Thrips are tiny! I only found them because I used a magnifying glass on one of the leaves of a sick looking plant. Though you can see them without a lens. Unless you know what you are looking for thrips will just keep getting worse.
So I ended up culling everything accept one cannabis plant that seemed to be unaffected most likely because it was on a different shelf and adult Thrips are poor fliers. I quarantined that plant over at my mothers house. And culled my entire garden. I cleaned everything thoroughly, the only thing I left was a bin that had a lid on it where I kept my compost that was made the year previous out doors. Since it had a lid my hope was that it was not infected with fungus gnats or thrips.
Starting Over
Fast forward about a month and I made a new sphagnum peat moss and compost soil mix. I filled the old aquaponic eb-flow bed with the soil mix and planted lots of things to see what would do well. The kids wanted peas and beans too so I planted those around the edges. I went over to my mothers where she is keeping my cannabis clone like a house plant. My mom loves that plant, she keeps it under a light I set up with timer set at 18 hours light and 6 hours dark. That thing turned into a bush under there! I took a bunch of cuttings and am attempting to root them. Of course the basement is cool so it seems to be taking forever for them to root.
The vegetables in the grow tent have exploded with growth. We have Swiss chard, beets, peas, two different kinds of lettuce, carrots, cilantro, arugula, broccoli, mustard greens and green beans. It was really hard to start all over. But I've got great optimism for what is happening in our little garden right now. To be honest, it's doing way better than before.
Recently my buddy I got the clones from asked me what to do about gnats. He says his garden is a mess with them. I told him about Microbe-lift BMT and now know where the gnats came from. If you bring plants home. Quarantine them! Look closely for any kind of distress before bringing them into the fold. I've definitely learned a lesson from all of this.
As I looked outside this morning drinking my coffee and writing this. I realize too that our big garden is just about ready for a few early planting attempts. We will just have to see what this growing season brings us.
Thanks,
