I’m just wanting to confirm what I feel is true, that this build up of mold is a normal process and nothing to be worried about? All my plants look great, but I transferred all my plants from terracotta to these plastic pots right before last years growing season and this has built up over that time. It seems like it’s just what would sometimes appear on the outside of my terracotta pots.
Care: A mix of inside and outside, depending on which ones seem to be better handling the 90F temps and 80 dew points, lol. I water using my tap, usually about once a week though I’ve recently been keeping a closer eye for dormancy on the ones outside. No fertilizer right now. Soil is an eyeball ratio of gritty mix (lava rock, turface, pumice, calcine clay) and soil, some pots 80/20, some closer to 60/40 respectively.
by k8ne09
4 Comments
I’ve only ever used a clear plastic pot once (for seedlings) and I had the exact same buildup in 100% pumice. I thought it was algae, but I don’t know for sure, and it appeared to have no ill-effect. The seedling roots didn’t seem to mind growing through it.
Hey there! From your description, it sounds like what you’re seeing isn’t mold but actually algae. Algae growth can be common in plastic pots, especially transparent ones, as they allow light to reach the soil, creating an ideal environment for algae to thrive.
Algae isn’t typically harmful to your plants, but it can be a sign that conditions are a bit too moist. Here are a few tips to help manage it:
1. **Reduce Watering**: Make sure the soil dries out a bit more between waterings. Algae thrive in moist environments, so letting the soil dry out can help reduce its growth.
2. **Improve Drainage**: Ensure your pots have good drainage and that you’re using a well-draining soil mix. Your gritty mix sounds good, but make sure it’s not retaining too much moisture.
3. **Move to Opaque Pots**: Consider switching back to terracotta or other opaque pots. They not only prevent light from reaching the soil, which helps reduce algae growth, but also allow better air circulation to the roots.
4. **Cleaning**: You can clean the algae off the pots if it bothers you. A mild bleach solution (1 part bleach to 9 parts water) can help, but make sure to rinse the pots thoroughly afterward to avoid any harm to your plants.
5. **Monitor Conditions**: Keep an eye on the humidity and temperature conditions. If you’re growing them both inside and outside, try to ensure they’re not getting too much humidity, especially the ones outside.
Your care regimen sounds solid overall, and it’s great that you’re mindful of dormancy and temperatures. Just a few tweaks should help manage the algae issue. Happy growing! 🌱
I’ve used these semi opaque pots for years. Honestly have not had any known adverse effects.
I am not really sure what it is. Was told it could be algae.
I don’t use clear pots for everything, but where I’ve used it, it hasn’t bothered any of mine. The algae will survive when the pot gets really dry, so imo you don’t necessarily have a moisture problem. But it’s always good to be aware of how much you’re watering.