Is it something bad about my basement?

Multiple types of media (Promix, Black Gold, Miracle Gro).

Captan doesn’t seem to help. H2O2 hasn’t done much. Letting the media dry completely doesn’t work. Most things I am starting in my basement grow room have rot or fungus to a varying degree - sometimes fatal, sometimes minor.

Onions - low germination and some damping off, but grew well once they got going.

Sweet potato slips - sprouted and grew. Dusted one with Captan, didn’t dust the other. Both potatoes rotted. I was able to save the slips, they rooted and are growing ok.

Tomatoes and peppers seem ok. Broccoli did ok.

Herbs and perennial flowers are pretty adversely affected.

Light is an 8-tube T5 HO. Air is actually pretty dry, under 40% humidity. Temp ranges from 60-80 (warmer when grow light is on) but lately runs more like 68-80.

Our house sits on a hill. Basement is dry with no water issues, and humidity tends to run low, especially during winter. A bit higher (and warmer temps) now, but not by much.

Bryan, I have limited ideas for your problem which may or may not be of any relevance, but here they are: Drier media results in less fungus and rot than wetter media. Second, it is my experience that media that contains a high percentage of ground bark and wood product tends to to promote fungus and rot. Media that is mostly or all sphagnum peat is quite resistant to fungus and rot.

I am letting it dry, and it is peat based.

I am a big believer of sunlight. I don’t think lamps can completely replace sun, only supplement. I have south - east and north- west windows in the house. I stopped to use north- west ones for plant starting. Plants there were always times worse than ones growing on sunny windows.

I don’t have a sunny window. Not one in a place where I can fit the plants, anyway.

I understand… How about greenhouse? I set portable on my deck. I have to heat it, though…


Magnus echinacea doing ok. Only a couple losses on these.

The hybrid/new cultivars, Mellow Yellows and Cheyenne Sprit fare worse. Maybe they just aren’t as vigorous as Magnus, which is a section of the straight species. Most look like this…I do have one survivor of each that looks like the first pic.

Columbine. Turns “bleached.”

Most things have low survival, but those that do end up doing very well, once they get over that critical phase.

Salvia - two of five survivors.

Luna hibiscus - 4 of 6 but three actually look good. The fourth is weak.

Evening Primrose - 3 of 6 survived…

I just watered. They were dry this morning.

I have had good luck using pure diatomaceous earth as a rooting medium. It retains exactly the right amount of water, you can’t overwater even if you watered hourly.
Not the powder the stuff that is the size of perlite.

I’m a member of the Tomatoville forum and about 6 years ago the guys started experimenting with DE as a rooting medium… The results were stunning. You have to be a member to see most photos.

On Our Figs many were having problems with rot when trying to root fig cuttings. So Gina tried using DE. I have been using it as an amendment to my soil mixes. I never really had problems rooting tomotes or other plants, so never used it to root, but I was having rot problem with fig cuttings so I tried it, it worked great.

Negra d’Agde

Roots formed easily

Here it is today

From the Tomatoville site. Giant Chinese peppers in Ultrasorb DE and on the right in Jiffy seeding mix. Clearly the DE germinated more seeds. And look how much more healthy they are.

Optisorb has larger particles and works better for figs. Ultrasorb has smaller particles and works better for seeds. Both are oil absorbent products made with 100% DE. O’Reilly’s Auto Parts carries these products near me. Check auto part stores for these products.

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Have you thought about watering from the bottom once the seeds sprout?

I used to use peat but it dries too fast for my liking and fungus gnats seemed to like it. I use compost with de and vermiculite now and haven’t had any damping off issues. I try to just bottom water once everything starts emerging. The soil soaks up the water by capillary action…or is it osmosis? :laughing: somehow the soil soaks up all the water it can hold!

Do you have any gnats flying around? The larvae eat seedling roots.

Yeah compost has bacteria that like to eat the damping off fungus, so that works well. Hundreds of studies show how compost prevents damping off. Gnats damage roots and leave the perfect entry point for the rot fungi. Over watering makes the bottom soil anaerobic, no oxygen, and that favors the wilts and the rots. Often people water too much. The top looks dry but the lower half of the cell is saturated. This is why DE works so well as this will never happen with DE. But letting DE dry will cause it to pull water from the plant itself, so it works, but can kill plants too, nothing is perfect.

I myself for seeds use 1/2 Pro-mix and 1/2 DE. For about 6 years now. Pro-mix never has gnats. This has worked really well for me. Everybody has to find what works for them. The DE is just another option and may work or not work for you.

Some interesting trivia Disney gardens uses DE as an amendment to all of it’s gardens
Many professional ballparks use it too.
Many studies show the beneficial qualities of DE as an amendment to soils (which is how I use it the most)

I didnt know de could pull water from the plants, good to know!

Yes we found that happened to some figs cuttings or we think that is what happened. But as an amendment in potting soils this is not a problem, the DE actually supples water to the roots. So for now it is just a theory. Overall it is a top rate rooting media.

The reason this cutting has so much DE stuck to it is the roots grow right into the DE to harvest water.


thats why worm castings works well to fight dampening off. its a form of compost.


I wish i could get them cheaper, i should probably make my own! The wife would not be cool with it! I would use them if I had a reliable cheap source. I live pretty much in the city. hard to find good sources of compost and many other rural items. Definitely urban here.

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I believe it was Lowes, where I recently saw bags of worm castings for sale for cheaper than i had ever seen before. It’s becoming a more popular amendment, might want to keep a look out for it at the big box stores!

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Thanks for that tip. Searched around and found “FloorDry” 25 lbs for $8 at TrueValue (shipped to local store free). I don’t know how it compares to Optisorb but since there are no O’Reilly’s stores close to me it’s worth trying for $8. Perlite works ok for me but maybe DE will work as well or better for rooting cuttings.