How to Deal With Black Mold on Peat Pots

Peat pots are a great option for starting seeds indoors. They are made from compressed peat moss, which is biodegradable and environmentally friendly. However, like any other growing medium, peat pots can develop issues with mold if conditions are right. Black mold is one of the most common and problematic molds that can grow on peat pots.

As a gardener, dealing with black mold on your peat pots can be frustrating. But don’t worry, with a few simple steps you can get rid of it and prevent it from coming back. In this article, we’ll look at what causes black mold on peat pots, how to identify it, and give you tips for treating and preventing black mold so you can get your plants off to a healthy start.

What Causes Black Mold on Peat Pots?

Black mold, also known as Stachybotrys chartarum, grows on peat pots when there is excessive moisture and humidity. The spores of the mold are always present in the air and soil. When peat pots remain wet for prolonged periods, it allows the spores to germinate and grow.

Some of the common causes of excessive moisture that leads to black mold on peat pots include

• Overwatering seedlings
• Poor drainage in seed trays
• High ambient humidity and poor air circulation
• Exposing peat pots to moisture before planting
• Not allowing peat pots to fully dry out between waterings
• Cool temperatures that slow evaporation

Black mold loves wet, humid environments with poor air flow. Peat pots that don’t fully dry out provide ideal conditions for black mold growth.

How to Identify Black Mold on Peat Pots

It’s important to promptly identify black mold on your peat pots before it spreads. Here are some tips for recognizing black mold:

• Black velvety or powdery growth on surface of peat pot or soil.
• Web-like black mycelium in potting mix or on pot.
• Musty, earthy smell from pots and soil.
• Seedlings stunted, yellowed or wilting for no apparent reason.
• White mycelium growing along with black mold.

The black mold growth can start out patchy, looking like black specks. Over time it expands into a dense black layer or coating over the peat pot and soil surface. The mold produces dark black spores and fine threads that give it a velvety or powdery appearance.

If you disturb the mold, it can release spores into the air. It’s important not to smell or get too close to suspected black mold.

How to Get Rid of Black Mold on Peat Pots

If you catch black mold early, it can be relatively easy to treat. Here are some effective methods for getting rid of black mold on peat pots and seedlings:

Improve air circulation and drainage – Prevent wet conditions that allow black mold to thrive. Use fans to improve air flow around plants. Water peat pots thoroughly but allow them to dry out between waterings. Ensure pots can fully drain.

Repot seedlings – If black mold is limited to the surface of peat pots, gently transplant seedlings into fresh, sterile potting mix in new containers. Be careful to keep roots intact and not disturb mold. Discard old peat pots.

Use hydrogen peroxide – This is a simple and effective way to kill black mold on peat pots. Mix 1 part 3% hydrogen peroxide with 4 parts water. Lightly spray or pour onto moldy areas and let sit for 10 minutes before resuming watering. Hydrogen peroxide kills mold spores on contact.

Apply fungicide – Look for a broad spectrum fungicide that lists control of black mold on the label. Always follow product instructions for safe and effective use on peat pots and seedlings.

Remove severely infected pots – Peat pots with extensive black mold growth should be discarded. It’s best not to try to save these, as the mold likely has spread into the potting mix. Remove infected pots carefully to avoid dispersing spores.

For any treatment, always avoid touching black mold with bare hands as it can be harmful. Wear gloves, wash hands, and sterilize any tools or surfaces mold came into contact with.

Tips for Preventing Black Mold

Prevention is the best way to deal with black mold on peat pots. Here are some tips to help avoid problems in the future:

• Let peat pots fully dry between waterings.
• Water seedlings early in the day so pots dry by nighttime.
• Use sterile seed starting mix.
• Provide good ventilation and air circulation.
• Avoid high humidity by growing seedlings at 65-70°F.
• Don’t let peat pots sit in water. Provide drainage.
• Discard old peat pots and replace with fresh ones each season.
• Sterilize trays & pots with 10% bleach solution between uses.
• Remove any diseased or moldy seedlings right away.
• Avoid overcrowding which causes excess moisture.
• Apply organic fungicide drenches at seeding as preventative.

Following proper watering technique is key. Peat pots should be thoroughly saturated with water and then allowed to fully dry out. Letting pots sit wet for days creates the perfect environment for harmful black mold to take hold.

Dealing with black mold on peat pots can be frustrating but doesn’t have to spell disaster for your seedlings. At the first sign of black mold growth, take action by improving air flow and drainage and using hydrogen peroxide or fungicides. Discard any heavily infected pots to avoid spreading spores. Most importantly, follow preventative measures like letting pots fully dry out between waterings and controlling humidity levels. With proper care and prompt treatment if needed, you can avoid black mold and have healthy, thriving seedlings all season long.