Indoor Gardens: 5b Gnat Notes and a Loose End or Two

Summer Dreams

Looking at the forecast, which contains snow and below freezing temps beyond March 1, I'm beginning to wonder when the outdoor gardening will commence. So I'm happy to have stuff growing inside. But some of it must go outdoors sometime. I'm grateful for the moisture we've had, yet I would like to see the temperature going up a bit more.

So, about the indoor gardening. After I finished my last post, I realized I'd forgotten to mention a couple of things about fungus gnats, and thought I'd update another thing or two.

One way to keep fungus gnats in check, when the population is small, is to use cider vinegar. Put a quarter inch to half inch of cider vinegar in a glass, add a drop of liquid soap, then stretch a piece of plastic wrap across the top. Poke a few small holes in the plastic and place near the fungus gnat infestation. Fungus gnats are related to fruit flies and will be attracted to the vinegar, where they will drown. Wine works, as well.

Sticky traps also are a way to check infestations of fungus gnats and other small flying pests. You can buy yellow sticky traps, or supplies to make them, from most garden supply places. Flying pests are attracted to yellow for some reason. Or you can make your own sticky traps with strips of yellow paint chips from the paint store and petroleum jelly, according to one Web site. So I tried it. I didn't have yellow paint chips, and had no plans to hit the paint department anywhere, but I do have some yellow cardstock, and the petroleum jelly was cheap at a discount store.

But stick with the actual sticky traps. The petroleum jelly didn't work. I even saw a gnat land on it, walk a few steps and fly away. Now I have a jar of petroleum jelly and no use for it. Meh.

As part of my strategy against both fungus gnats and damping off disease I purchased a different type of potting mix, a "soiless" mix. It would be looser and dryer than the potting soil I'd been using for the microgreens, I thought.

Well, that is indeed true. However, the microgreens did not sprout as thickly as they had before and are growing rather slowly. The stuff is apparently too dry and has no nutrition. The microgreens I planted a week later in the old potting soil sprouted thickly and are about the same size as the ones planted earlier. So, another "meh." I'm going back to the old mix and just keeping up the gnat strategy -- gnategy?

More snow and freezing drizzle this week. Sigh.
Stay safe out there.

Gardening Indoors 5: Gnatty Problem

Houseplants are a great addition to the decorating scheme.

They're baaaaaaack. (Violin going "screeech screeech screeech")

Those naughty gnats have returned. Fortunately, not in the numbers they had before. I have a plan; I am prepared.

After we had our microgreens going for a month or two, we noticed a proliferation of tiny black fly-things swooping up from the soil every time we cut microgreens. I'd seen these things before, hovering about the houseplants, but never in large numbers, so I wasn't ever concerned about them. However, they came up almost in clouds out of the microgreens.

I thought I knew what they were, but still I pulled out my organic gardening reference book, and did some online searches.

Yep, I was right. Fungus gnats.

Most of the info I found indicated that fungus gnats weren't a problem, although some said that they could nibble on plant roots, etc. But none of the information I found caused me concern. The fungus gnats were an annoyance, nothing more (so I thought, trying to avoid taking any action).

However, some of the microgreens started falling over, or not germinating at all. Damping off disease. (See my post from 2/4/19) The gnats could be transmitting damping off disease while hopping from one container to another. On top of that the weekly Horticulture Newsletter from Kansas State University Extension said that fungus gnats do cause damage. They won't really do harm to my mature houseplants, partly because they're so tiny and the plants are big. Because of the conditions the fungus gnats require, they don't proliferate to extremes in the larger pots, either.

But they are an issue for tiny, vulnerable seedlings, like my microgreens, and now my seedling transplants (see last post). And it was in the microgreens where they proliferated most.

Because... fungus gnats need moist soil conducive to fungal growth (which they eat as larvae and maybe as adults). One way to keep them under control in regular size houseplants is to always let at least the top two inches of soil dry out between waterings. Easy enough. You can't do that with microgreens, though, which have only an inch of soil to begin with. If I tried letting it dry out completely I'd end up with a bunch of withered seedlings -- damping off or no damping off, fungus gnats or no fungus gnats.

Drastic measures were needed. So I harvested all the microgreens and removed the soil-filled trays, planting no more microgreens. I purchased Mosquito Bits (like Bacon Bits that are not made of actual bacon, they do not contain actual mosquitoes). The Mosquito Bits contain a biologic toxin Bt, but not the same variation of Bt that I spray on my cabbages against the various butterfly and moth larvae that eat them. MB contains Bacillus thuringiensis var. israelensis, which not only kills mosquito larvae but also fungus gnat larvae.

Other products with Bt-i are Gnatrol and Knock-Out Gnats. The Gnatrol I found only in large quantities. It took some searching to find it available in anything less than a 16-pound bucket for more than $400. I had trouble finding Knock-Out Gnats. The Mosquito Bits were $19 for 30 ounces, which should last a little while. You might even be able to find them at a hardware store.

So I put the MB on the soil in my larger potted plants and watered to release the Bt. I didn't want to put it on the microgreens soil because they are only a couple of inches tall when you harvest, and so close to the soil. Bt is pretty safe as insecticides go, but I'd rather keep the greens clean. So we had no microgreens for two weeks. The gnats disappeared. The microgreen operation started back up. We started seeing a gnat here and there, so I reapplied the Mosquito Bits, and I keep a spray bottle of Safer Insecticidal Soap in the plant room. Whenever we see a gnat doing an aerial display we grab the bottle of soap and squirt, praying we actually hit it. The soap only works on contact when it's wet. Once it dries, no luck.

The gnats disappear quickly, so we can only guess where to spray. We coat the leaves in the area we saw the gnat to increase our odds. We don't spray the microgreens or the baby cabbages because insecticidal soap can damage seedlings.

The tactic is working, but requires diligence and repeat applications.

Other products also help to prevent fungus gnats. One product is essentially ground up glass that you spread in a half-inch or so layer over the entire soil surface creating a barrier to the gnats so they can't lay eggs or eat roots. Pretty much anything that creates such a barrier would work. My first reaction to the glass was "no way." But I would maybe consider it for a larger potted plant that won't be repotted often. However, it's not cheap. So I'll stick with my current program.

Fungus gnats. There are worse pests to have and shouldn't be an issue with ordinary houseplants. But if you've got microgreens or are starting transplants, don't ignore them. Don't be like me.

Indoor Gardening 4:Seeding Hope

Snow pea microgreens. Because I had to have a photo of something

besides soil-filled pots.

Another morning with a single-digit (Fahrenheit) low.

So what did I do yesterday?

I planted!

I know have two full flats of cabbage seeded, and a half-flat each of broccoli, lacinato kale, celery and radicchio. They sit on my light shelf now. In a few days, the seeds should crack open and send down their radicles (seed roots) and poke up green seed leaves. In about six weeks (weather permitting) they will go into the garden to become tasty vegetables.

I hope.

Each time I plant a seed I am filled with optimism and hope. And I understand it's a gamble. So much can go wrong. But either it doesn't go wrong, or I am able to mitigate and overcome. I am optimistic that the weather will be at least somewhat hospitable for the plants and hopeful that all the things I do will bring a good outcome.

Every year I do this. Start plants indoors to transplant later. This is how I harvest cabbage and broccoli before the height of summer heat; and how I start more cabbage and broccoli during the summer heat to harvest in the fall.

Starting your own transplants requires a little equipment and planning. I have four five-foot long shelves each outfitted with two four-foot fluorescent shop lights. But you don't need that large of a rig to start your own transplants. I start a lot of plants -- I'm expecting 60 cabbage plants, 12 broccoli plants, 12 lacinato and 12 each of celery and radicchio. And that's just the beginning. One year I had to replace most of my cabbages and broccoli because of late cold and nearly choked when they rang up my purchases at the nursery.

But even if you don't plant that many vegetables (or flowers and herbs) starting your own transplants has its benefits. Even if you only plant a half a dozen of any one thing.

Pots filled with soil and waiting for seeds.

First of all, by buying seeds you have more control over what varieties you grow. The local nursery will carry only a few popular varieties of plants, so you might be missing out on something you like even better. Maybe cabbage varieties don't matter much to you, but what about tomatoes? Probably thousands of tomato varieties exist, but the local nursery may carry only six, plain, ordinary, everybody grows them varieties. Maybe they carry a couple of heirloom varieties... but listen -- thousands exist! Pink ones, red ones, yellow ones, green ones, white ones, orange ones striped ones, giant ones, smaller ones, cherries, currants, plums, pastes...

Another factor in favor of starting your own: Your local nursery may not carry vegetable plants for your fall crop.

On top of this, starting your own transplants is satisfying and a good way to get an early start on gardening when the weather outside is frightful.

You need:
Containers. I used to start my transplants in little pots I saved from buying plants. Then I stopped having to buy so many plants, I started planting more stuff and didn't have enough pots, and those pots started getting broken up. So I wound up having to buy some. Because I plant a lot of stuff. But you can repurpose a variety of things to use as pots. Just wash plastic and styrofoam drink cups you get from the fast food joint, poke a few holes in the bottom. Voila! A plant container. You'll want something to catch the water dripping through the holes, but you can repurpose a lot of things for that.

Pots seeded and marked (I cut up plastic lids from large yogurt containers

and mark them with a permanent marker. "Bruns" stands for Brunswick

cabbage, while "EJW" stands for Early Jersey Wakefield cabbage. You can 

use any number of things to mark your seedlings. You'll want to know 

what's supposed to grow. The brownish powder is cinnamon, which I hope

will prevent damping off disease (see my last post for more on that).

Soil: Don't just dig some from the yard. It will probably get hard as a brick. Buy a good potting soil, or soilless planting mix. I always wet mine before putting it in the pots.
Light: Even a south window might not provide enough light. You don't have to buy grow lights, though. Fluorescent lights are suitable, even led bulbs might work fine. Whatever size fixture fits your operation.
And finally -- Seeds!

Some seeds require more warmth than others. Check the seed packet for tips on what is needed, or search online for growing tips. The cabbages will sprout in relatively chilly temps, while pepper and tomato seeds must have some warmth. Find the warm spots in your home and put the pots there until the seeds sprout. They won't need the intense light until they have leaves. Cover the seed pots to maintain moisture until the seedlings are an inch or two tall -- or more. If you're repurposing things and don't have the handy clear plastic "domes" that go on seedling flats, use plastic bags, but stick popsicle sticks, broken pencils, or sticks from the yard in the soil to hold the plastic off the soil.

Even though these plants you're starting are intended to live most of their lives outdoors. This is still indoor gardening. Enjoy the adventure.

NOTE: If you have any questions about starting transplants, please leave a comment below and I will do my best to answer it.

Indoor Gardening Tres: Adding Spice

Your tiny seedlings look green and healthy, and then suddenly fall over.

Maybe you just waited too long to water them. But wait... the soil is damp. Or you water them and they don't revive. Were they dry too long or ...

Is it DAMPING OFF Disease?

Damping Off disease is caused by several species of fungi and gets into your indoor garden by way of contaminated soil, seeding pots and trays, tools, and even your hands. Damping off essentially only affects seedlings, and possibly cuttings. Sometimes it prevents seeds from germinating, or they die as soon as they germinate. Your mature plants won't be bothered by damping off.

But when you're starting transplants from seed, or growing microgreens (see last post) damping off is a real possibility.

I haven't ever had a problem with damping off when starting transplants, as far as I can recall. Maybe a few seedlings failed due to it, but it never created an issue that caught my attention. So when symptoms started showing up in the microgreens I resisted. I thought that the reason the peas started to germinate so poorly was due to some other cultural thing. I tried soaking the seeds before planting, and covering them with much less soil. But to no avail.

Then when a tray of garnet amaranth came up sparsely and most of the seedlings fell over even though the soil was damp, my hand and brain were forced (by my husband's insistence). I didn't even need to hit the "search" button on the computer to recognize the issue. As soon as I was willing to admit something was wrong I knew what it was. However, I did go searching the Internet before declaring the issue... damping off disease.

Conditions that favor damping off include constantly moist soil and crowding of seedlings. When raising transplants, I try not to crowd the seedlings, but with microgreens that's the whole point. You want to pack your container with tiny green stuff. And you can't let the soil dry at all, because you've go only about and inch of soil to start with.

Exacerbating the issue were the facts that I started reusing the potting soil, and I did not clean my trays after each use. Big Point Here. Dirty containers, dirty tools and dirty hands can and will spread damping off (as well as any other disease that might be present). Sigh. I knew better. But it had never been a problem before. However, point taken. I will from now on wash the dirt from my containers after every use and then soak them in or spray them with a 10 percent bleach solution (one part bleach to nine or 10 parts water). Leave that sit for 30 minutes and rinse thoroughly. It is also important to clean tools (like scissors) with each use.

Your best bet in preventing damping off is to use fresh potting soil each time. However, with the amount of microgreens I'm growing that's a lot of potting soil. I can reuse the soil, after picking out as much of the plant material as possible (I know, it does sound like a pain in the derriere, and it is, but that's a lot of potting soil) and sterilizing it. To sterilize the soil put it in an oven-proof pan four inches deep (it should be dampish, I think) and place in a 200-degree oven for at least 30 minutes. I'm told it creates an unpleasant smell. But, hey, it's only for 30 minutes. Open a window.

Another preventative measure is to use some herbs with anti-fungal properties. For decades I've heard that spraying seedlings with a strong chamomile tea (cooled, of course) on a regular basis prevents damping off. I've never tried it because damping off has not been an issue. More recently I discovered that cinnamon has antifungal properties and will prevent damping off if sprinkled on top of the soil after planting. One source said that only Ceylon cinnamon will work.

You see, not all cinnamon is the same. There are actually several species of cinnamon that have slightly different flavor characteristics. Ceylon Cinnamon is considered the "true" cinnamon, and supposedly has more anti-fungal punch than the other types. It's also the most expensive of the cinnamons. Ceylon Cinnamon also contains far less coumarin than other cinnamon species, which is only a concern if you are using it in therapeutic quantities or are sensitive to coumarin (which thins blood, and can damage the liver in large quantities). Most of us aren't going to experience issues by using the other cinnamons, which tend to have a more cinnamony flavor than Ceylon.

So I've ordered some organic (don't want to introduce nasty stuff into my microgreens) Ceylon cinnamon as cheap as I can find it. In the meantime, though, I've used some other cinnamon, Vietnamese and an unspecified type, and have not yet seen signs of damping off. But I've only just begun, so we'll see. I even sprinkled on some cinnamon when I started my leeks and onions, even though I've never had trouble with transplants. It's an easy enough step to include, so better safe than sorry.

Other preventative measures: If chamomile and cinnamon aren't available, spray with a garlic tea, or use sulfur powder (not recommended for microgreens), or powdered charcoal. Use a peat based, soilless growing medium, and cover seeds with vermiculite or dry sand which will keep the seedlings drier and discourage fungal growth. Provide some air circulation with a fan on low might help.

One more way damping off possibly might be spread is by insects, namely fungus gnats, which (as their name indicates) like to chomp on fungi and decaying plant matter. I'll get to them in a future post. Until then, enjoy the smell of cinnamon