For context, my very first sowing (primarily Lophophoras + E. Rigidissimus - viewtopic.php?p=404475#p404475), I had what I now realize were pretty decent germination rates, and no problems with mold, fungi, etc. Well, that is until I tried to transition them to reduced humidity conditions…but that’s a post for another time.
After that sowing, I ran out of the soil mix I used, and subsequent sowings have been plagued with (1) 0-5% germination rates; (2) mold and fungi outbreaks galore; (3) damping off; and (4) stunted growth rates (relative to my first sowing).
In the last two months, changes to my methodology has resulted in improvements to problems 2-4, though my germination rates continue to be very poor. I’ll continue to tinker with my soil mix and sowing methods to try and move the needle on the germination rates, but in the meantime here goes…
Pot Prep
1) I use individual 3” pots and use a soldering pen to make drainage holes in the bottom. After soaking them in a 50/50 bleach mix overnight, I run them through the sterilization cycle in my dishwasher, and then spray them with 70% rubbing alcohol in front of the flow hood, where I leave them to dry. https://www.amazon.com/dp/B0B4S2ZSDB?ps ... ct_details
2) I place a piece of felt (previously sterilized in pressure cooker, then soaked in 3% hydrogen peroxide before use) over the holes, and then a single layer of 3/8” - 5/8” zeolite and chicken grit rocks on the bottom of each pot before filling them with whatever soil mix I’m currently experimenting with. I’ve experimented with both mixes sterilized in the pressure cooker and “out of the bag” with no noticeable difference.
3) I then place all the pots in a large lidded container before adding 30-60 ml of ~1.5% hydrogen peroxide to each pot. The grittier the mix, the less hydrogen peroxide I need to saturate the mixture. I then let the pots sit for anywhere from 24-72 hours, depending on my schedule.
4) After the pots have been soaking in the hydrogen peroxide, I then add 20-30ml of prepared BanRot fungicide to each pot, followed by ~10-15ml of distilled water to “water it in” as the directions recommend. Per the manufacturer’s guidelines, BanRot should be applied at least two days before sowing seeds, so I let the pots sit for 48+ hours, again, depending on my schedule, I’ve let it sit for up to 5 days before the next step.
https://seedbarn.com/products/banrot-40 ... 0278334564
Note: This stuff is no joke and I follow all recommended PPE guidelines which can be found here: https://www3.epa.gov/pesticides/chem_se ... 210422.pdf
5) I next add systemic insecticides (Arber Insecticide, SNS 209, and Imadicloporid), a natural bacteria-based fungicide (Arber or Garden Friendly Fungicide), and a Vitamin-B supplement mixed into enough distilled water to add 20-30ml of solution to each pot. https://www.amazon.com/Mad-Farmer-Vitam ... B00F5EQSYI
Before I started using BanRot, I’d also experimented with adding other fungicides (Phos; Chinosol), but I’ve found no difference in results when using them at this step, so to keep it simple, I no longer do. I then let this solution soak in for at least 12 hours.
When I was first testing out this method, I let the fully treated pots sit in the incubation chamber for a month to see if any mold would grow without any seeds, and when I finally showed seeds in those pots, they worked just fine, so technically you can keep the pots in this state for as long as you need in a sealed environment (i.e. lidded container).
6) Just before sowing the seeds, I add a super thin layer of top dressing that has been previously sterilized in a pressure cooker. Currently, I’ve been playing around with a bunch of different substrates (chic grit, 1-3mm zeolite, limestone grit, 1-2mm aquatic pebbles) but I can’t say I have a favorite since my germination rates continue to be so low across the board
Seed Prep
1) After counting out seeds, I place them in little baggies I make with fine mesh baggies made for tea and hot glue. The bags then get soaked in distilled water for a few hours to overnight, usually in the fridge.
2) I then soak the bags for 10-60 minutes in a 40% bleach solution (I aim for 10, but sometimes my ADHD gets in the way). The bags then get rinsed under running water (the lowest trickle possible from my sink faucet) for 1-2 hours.
3) I then soak the bags in 1.5% food grade hydrogen peroxide for 4 hours, and then again perform a running water rinse, though usually for 30-60 minutes, unless I forget, and then it can be up to 2 hours.
4) At this point, I either place the bags in a new/clean plastic baggie filled with distilled water, or, if I’ve time things right, I will place the bags into a bowl of warm distilled water with a magnetic stirring stick at the bottom and place the bowl on top of the magnetic stirrer and let that run for a few days. As I posted previously (viewtopic.php?p=406005#p406005), I will change out the water every 12-24 hours, using previously pressure cooked rain water for the last 24 hour “swirling rinse”.
Sowing Method
I have adopted the C&D Sowing Method verbatim (https://www.cactiguide.com/forum/viewto ... 26#p300126) with minimal variation, except:
1) I continue to lean on my mushroom growing roots and sow seeds in front of a flow hood, and I like to clean my gloved hands as well as all my tools with 70% rubbing alcohol between sowing individual pots. Because the pots were treated with BanRot, while sowing, I also use PPE, and place the pots on top of clean wrapping paper leftover from my last move. The used paper then gets thrown away after being left to dry completely in front of the flow hood.
2) ~30minutes before I get started, I soak a bunch of toothpicks in 70% rubbing alcohol, and use those to transfer seeds from the bags they were soaked in into the pots, using a new toothpick in between bags/pots. Those toothpicks then get placed in some foil and are put through a sterilization cycle in the pressure cooker so they can be reused later.
3) I use the lids that came with the pots to cover each pot individually. After all the seeds are sown, the pots are placed on top of a capillary mat inside my germination chambers/wet box (a translucent restaurant supply full sized pan on top of a heating pad and under grow lights).
A week after the first sign of germination in a given pot, I crack open the lid of the pot slightly, but leave the pot in the germination chamber/wet box.
https://www.amazon.com/dp/B001VT5IN8/re ... ZAM6A&th=1
My oldest seeds sown using all three of these methods are just under two months old, and so far, so good…except for my germination rates.
Someone suggested I try using sifted Poots cactus mix (https://pootscactusnursery.com/shop/p/poots-soil-blend), and so half the pots I currently have soaking use the Poots mix (sifted using a 2mm screen) as is, and the other half uses the Poots mix amended with 1/8” pumice, 1-2mm chip grit, zeolite, limestone grit, etc. I plan to sow a new batch of soaked/rinsed seeds in those pots over the weekend. That said, I’m always open to ideas, so feel free to chime in if you have any helpful thoughts or suggestions!
