What is that white fluffy stuff covering your seedlings? It’s fungus, but don’t worry – you can get it under control.
You tend to get this white mold, a type of fungus, if you use soil from outside to start your seeds or have a greenhouse with poor air circulation. I’m guilty of both and have had more than my fair share of experience with the frustrating fungus.
Knowing how to prevent this problem is half the battle, so let’s talk about that first.
How to Prevent Mold and Fungus
Use a soil-less potting mixture or store-bought seed. Like I said, you’ll never catch me using anything but my garden’s existing dirt, but you may not feel the same way.
Don’t use paper, egg shell, or other organic containers. Don’t use popsicle sticks to identify your plants – stick tape on the container and write on that instead. These organic objects can introduce fungi and act as a host to any fungi that develop.
Sprinkle the top of the dirt with cinnamon, water the seeds with chamomile tea, or apply other anti-fungal agents. You can only use some of these remedies after the seeds have developed their first two leaves, including neem oil, apple cider vinegar, and hydrogen peroxide. Otherwise, the seeds may not germinate or survive.
Keep your greenhouse or home’s air flowing and remove the plastic plant covers. Set up a small fan or crack some windows, weather permitting. The moving air will deter fungi.
Turn up the lights and, seriously, remove the plastic cover. Adding more heat and removing the plastic will help dry out the soil a bit faster. Yes, you’ll have to apply water more regularly, but that short period of dryness will deter mold and not bother the plants.
Put the seedlings near a heat source. Yes, more heat can encourage fungi, but it will also encourage a speedy germination of the plants. The faster you can get them going, the faster you can use more aggressive anti-fungal treatments. Just take care not to scald them.
Removing Mold and Fungus
If you’ve developed a fungus, I suggest you perform the following steps in order. If one doesn’t apply to you, just skip it.
- Scrape off a thin layer of top dirt and apply cinnamon or another anti-fungal agent. Cinnamon has worked the best for me. If the seeds are small and haven’t germinated yet, scraping off the top layer may remove the seeds. Wait until they have germinated if this is the case.
- Allow the dirt’s surface to dry, at least down an inch, before watering again.
- If the mold spread to an organic container, use a new one, so long as the plant is large enough to survive the transplant.
- Stop using a self-watering tray. You need to more precisely control how much water the plant is getting. Instead of using a tray, you can use a spray bottle on the bottom of the container, but this can be tedious.
- If the mold has spread to the seedling itself, gently wipe it down with a damp paper towel.
- Begin watering from the bottom of the container by dipping it in a tray of water. Don’t leave the plant in the tray – it will absorb too much and worsen the fungus.
- Refresh your application of cinnamon or other anti-fungal agent every three days.
If you haven’t seen this problem before, make sure it’s not root hairs. These thin white hairs look much like the fungus, but they are limited to the root. Look at this video to see: