Cloning -- The first thing to know.

The first thing to start with when taking cuttings is a clean (that means sterile) environment. If there are going to be any microorganisms, you want to control which ones. When my clone kit came from HTGSupply.com, it was free from plant pathogens. I rinsed the dome and tray with tap water and then put in my first cuttings. However, after each generation of clones, you should gently wash the dome and tray with soapy water. You can sterilize your clone kit by spraying it with 25% hydrogen peroxide 75% water in a spray bottle.
I have had a few people write about stem rot etc. with cuttings. If you have tried taking cuttings before and gotten any kind of fungal problems, you have fungal spores in your grow area. You can’t see them, but they are there. To be honest, all of us will have fungal spores in our grow area, they are virtually everywhere. You need to clean the cloning dome and tray but you also should clean the surface (table shelf etc.) where you will place the tray, and while you are at it, you can wipe down the walls and floor etc. Use a 10% bleach or a 25 % hydrogen peroxide, or a vinegar solution to clean the area. You can use a higher percentage of vinegar, up to 50% to wipe down the walls etc. Vinegar is organic and nontoxic to non-microscopic organisms. Vinegar is an acid so it will sterilize the area. You can then make a 25% hydrogen peroxide solution and spray the area with a spray bottle. Let it sit for several minutes before wiping it up with paper towels. You should let the area dry with a fan (or better yet a carbon filter). Your cloning area should be dry with low humidity to help to kill off any remaining fungal spores and not allow the ones that enter to develop.
You can get obsessive about cleaning, just know that the cleaner the area you grow your cuttings the better. However! if you don’t have problems with stem rot you don’t need to spray peroxide solution everywhere, or use bleach, but you will get better results if you keep your cloning area clean and free of dirt, dead leaves, rags and other organic surfaces. Bleach does react with some plastics putting off toxic fumes, so be careful when using.

Good Growing
Dr. E.R. Myers