Seeds in worm compost


When I started raising worms last year I wondered why other people either microwaved or froze the food.
I stored the compost I gathered over the winter in the garage and used it in the mix for the seeds I started In Feb. Tomato seed love these conditions. I have hundreds of tomato plants.
Now I will either freeze or zap the worm food. My question is:Which works best or not at all?

Hanceville, AL(Zone 7a)

My guess is that heat would work better. I have sterilized soil in the oven for years, also have stored seed in the freezer for years. Other people might have different experience. Luciee

Superior, MT

I usually freeze my food before I use it in my worm bins and, yes, I have lots of tomato and pepper plants sprouting in them. I just pull them and tear in half (so they don't continue growing) and put them on top of the bedding so that they eventually will be eaten.

Helena, MT

OK Chuck you hit upon a dilemma we all face with using our spent worm media for germination and potting mixes. I have gone a different route and that is to heat sterilization in my lab oven the spent media before using it in the germination process. But then I realized I was losing much of the benefits of the spent media so I stopped this and just put up with the rogue tomato plants hoping I could tell the rogues from the tomato seed I had planted. Then along came Twiggybuds with her suggestion for using Hydrogen Peroxide for starting new seeds in my germination mix. I now initially bottom water a flat with a 1:32 dilution of 3% hydrogen peroxide to water. Did it stop the rogue tomato seeds germination in my germination mix??? NO it did not, but it did cut down on the mold and dampening off problems. So the problem still exists and probably always will. I haven't gone to the trouble of freezing the worm food prior to feeding it to the worms, but tomato seeds are very virulent and I doubt freezing is going to completely kill all the tomato seeds. I have seen volunteer tomato plants in my garden and Lord knows how cold it gets here in Montana during the winter

My only other solution to the problem is that I am not growing a variety of tomatoes this season. My main production crop will be Stupice tomatoes and if I get a rogue seed or two germinating in my germination mix it will probably be the Stupice. My other choices are a couple of cherry tomato types and I doubt that any of these will ever see a worm bin. My five year old neighbor "Master Luke" will see to that.


I had my hand operated on thursday so this will be short. I believe one minute in the microwave will kill any seed. if I zap anything with seeds wont this solve the problem?

Helena, MT

Probably Chuck, but I would never get a way zapping worm food in my 'wife's' microwave. I just look at rogue seeds like they were garden weeds. You can generally spot the rogues and toss them if you don't want to keep them.

Another thought came to mind Chuck, I place all fall spoiled tomatoes in the outdoor worm beds instead of the indoor bins so I don't really have much of a problem with my germination mixes having rogue tomato seeds. The last time I had tomato seeds in one of my worm bins was when I did an experiment to see if I could germinate these seeds directly in the bin and transplant them individually into their own peat pots. The experiment worked but I had other objections to that method of germinating tomato seeds.

So what did you do to your hand Chuck?


Cut the end off the long finger about 20 yrs ago and the ligamate grew tumors on it till

i couldent open the hand any longer.

Helena, MT

Ouch, hope the surgery helped Chuck.


Howdy all! I realize this thread is a year and a half old, but figured I'd ping it anyways... I'm a relative rookie to this worm wrangling thing and was wondering... could the germinating seeds be overcome by spending more time in the worm bin? I would think that given enough time, the seeds would sprout in the bin. Then, without enough sunlight to root and become seedlings, would become further worm food. no? All responses gratefully accepted.

Helena, MT

You got it wormkeeper. I pluck the sprouts at feeding time and into the blender with the other scraps.

Wake Forest, NC(Zone 7b)

For mraider3's comment that he can't get away with using the kitchen microwave, I would suggest getting to a thrift store and getting a used one for the garage or workshop. There are many used microwaves available, pretty cheap. BTW, I don't think I would want to put "worm food in my kitchen microwave, but I just turn the top part of my worm pile anyhow. I know you use the results of your worms labor for all your plant starting pots.

Camanche, IA(Zone 5a)

Well, here's my 2 cents worth, I got a cheap blender from Goodwell or a yard sale, I blend up the tomatoes, squash, etc. in the blender,so i don't have trouble with seeds. Hope thats an idea for you! Phil

Helena, MT

flip, I hate to disagree with the no seed theory by using a blender. If you blend tomatoes the seeds will germinate. Vermicompost is an ideal medium for germinating tomato seeds, and other seeds for that matter. I keep a light on my bins 24/7, and all kinds of seeds actually germinate. But as I mentioned before... so what, just add them to my bucket of fermenting worm food and grind them up. Again, the only problem with vermicomposted rogue seedlings as I see it, is when you are using vermicompost to germinate a specific tomato variety you may end up with something different than what you intended.

I too have purchased used blenders when available and keep a back up of the type I like. Since I prefer the glass bowl vs. plastic I am always on the lookout for these blenders even if the motor isn't working properly. Glass bowls are easier to clean than plastic which also retains odors if you leave fermented worm food in them for a day or more. Estate sales are the best place to find these since glass bowls are being replaced with these cheaper plastic ones. Just make sure your drive unit is a match for the bowl, Typically there are two types of drives and I prefer the older square pin type in the center of the drive motor.

For new readers I would also suggest using some type of bucket to store your scraps in until you are ready to blend them. I picked up a couple of baby dipper pales with lids at Goodwill. I line them with 13 gallon clear trash bags which helps keep them cleaner or easier to clean. Add a little water to the mix and it will begin to ferment. Since baby dipper pale lids are loose fitting the mix should not go anaerobic right away, but if it does finish off the mix and start over, or rotate the pales as I do. Molded bread or veggies which have been stored too long in your refrigerator are great for fermenting the other things like potato and banana peels. And remember blended fermented food scraps are virtually worm ready them to feed on.

Frankfort, KY(Zone 6a)

If a tomato did not taste so good they would be an invasive WEED.

Helena, MT

That's what I keep telling my wife. Here carrot row last year had a rogue tomato plant sprout in the row and did nothing, while the rogue pumpkin plant practically smothered the carrots. She can not get the idea that these are weeds, so I left her to tend to her rogue plants which didn't do anything but get in the way. Now she's giving me a hard time about my pruning of the raspberries. I tell her it's like thinning the herd which is the middle boys reasoning for hunting, but I don't think she gets the analogy. I've run out ideas to explain why you don't let plants go amuck in your garden.

SE Houston (Hobby), TX(Zone 9a)


"Again, the only problem with vermicomposted rogue seedlings as I see it, is when you are using vermicompost to germinate a specific tomato variety you may end up with something different than what you intended...."

I'm about to start 16 varieties of heirloom tomato seeds. So, my safest bet in working with the worm castings (once I start getting some...), is to ONLY add it to my tomato beds AFTER my heirlooms are labeled and planted out, yes? In order to keep track of the wanted heirlooms vs. any unwanted rogue seedlings that may pop up from the vermicompost, yes?

Whew! So, I guess I'll not be starting any heirloom seeds in 100% vermicompost....


Helena, MT

OK Right...I use a bag of MG seed starter for tomato seed sowing. You could sterilize the spent vermicompost, but you loose the effect of the compost microorganisms. Better used some where else, like in your potting up mix. As I have mentioned before I like peat pots, having worked half a century with peat I like the way the pots tell you when to water and when to transplant. If you save seeds and plan on sowing a lot of tomato plants you can sow more than five seeds in a single peat pot as I do. I have planted more than enough to pot up a single flat, but I prefer the number five so I can work with the seedlings without being to rough on them, not that I can tell if untangling roots seriously affects tomato seedlings.

If after potting up the seedlings in a single peat pot I find the weather not suitable for planting out even in a covered cage, I can always transplant again the tomatoes which have roots beginning to grow through the peat pots. I use a two gallon plastic pot for this purpose. Next season I will be planting two tomato plants per hole rather than one. So if I transplant to the two gallon plastic pots I will be placing two plants in each pot instead of the previously one.

When potting up seedlings or transplanting the ratio of vermicompost to other components in the media is generally 10 to 40 percent of the vermicompost to other components. My spent media is not 100% castings so I can go to the high side of 40%, however I prefer to use about 20% spent media, and a mixture of spent raised bed media, aged cow manure, and some wood chip fines. Pretty much the same procedure for my cayenne pepper plants which stay potted up and are raised in a 4' x 8' raised bed. This raised bed is dug down three feet and the bottom is lined with wood chip fines. Beds are covered in the early spring and fall with old window panes. Eighteen pepper pots per bed which will also contain either two or three cayenne pepper plants per pot next season.

Pepper plants do not seem to mind crowding, but I was surprised to hear from Ed Hume Seed Company's library (fruit section) that some commercial growers where planting four plants per hole in order to stress the tomato plants into producing fruits earlier. Our sixty to ninety day out door growing window needs all the help it can get.

Fredericktown, MO

If you fill your flats but don't plant anything, let the rogue seeds germinate, pull 'em and maybe even repeat to let any other seeds to germinate, then start your seeds. I have also killed a lot of seeds just with a clear tub in direct sun, kind of like a solar heater-not as harsh as microwave.

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