Sterilize Your Seed Starting Pots
"Sterilize Your Seedling Pots with Bleach and Water" I think this advice makes good sense. We don't want our young emerging seedlings to be overcome by destructive pathogens. By killing off all offending fungi and bacteria, we ensure a nice sterile environment for the seeds to thrive. Of course this concept won't do much good unless your seedlings are also grown in sterilized soil.
THE CHALLENGE: In concept, this sounds great. But in practice, it can be cumbersome. I've cleaned and bleached all of my seedling containers. It felt great! But that lasted for about a month. I soon used them all and had to start reusing them. Springtime is SO busy! I don't always have time to mix up a batch of bleach and water. That is especially true when I only have a couple of pots that need cleaned. I might be doing good to just get a potting mix together and throwing in my seeds.
THE REALITY: So after years of playing it safe, I started taking chances. After all, we don't sterilize the dirt outside, when we direct sow our seeds, right? So I stopped using bleach. Just some Dawn soap and hot water. Sometimes no soap -just a quick rinse. If potting mix fell on the ground, I'd just scrape it up and plant my seeds in it. The results? It never seemed to matter.
To avoid diseased seedlings, I've shifted my focus. Even if pathogens are present, a healthy plant is will have the vigor to fight off diseases. Make sure nutrients are well supplied. Plants need adequate moisture. But be careful not to over-water them. Excessive moisture can stress plant roots and will promote diseases like damping off. Provide adequate air circulation. Humidity domes should be removed as soon as seedlings emerge from the soil.
For strong robust seedlings, provide them with high levels of broad spectrum light. Strong LED grow lights have worked nicely. Although they're less efficient, high output T5 bulbs are also effective. They give off a small amount of UV light spectrum which is good for optimal immunity. To get the most from a light source, I try to avoid overcrowding my seedlings.
The bottom line: Keeping seedling trays and containers sterile is great advice. But if my life is chaotic and I'm feeling overwhelmed, this is a corner I can cut in the Spring. Then in the Fall, I gather up everything and clean it all, in one big batch.