How to Get Rid of the Mold Growing in My Seedling Flat
Mold in a seedling flat probably isn’t harming the seedlings, but it’s a sign that the growing conditions aren’t quite right. White or brownish molds that appear on potting media are saprophytic fungi, which live on organic matter. These molds don’t attack the living tissue of seedlings, but they can make it difficult for seeds to germinate. You can sometimes remove the mold by agitating the surface of the potting soil.
What Causes Mold in Seedling Flats?
Mold in a seedling flat is a sign that the potting soil is too wet. The seedlings may be growing healthily, but they’re at risk of developing a condition called damping-off, which causes their stems to collapse and the seedlings to die. Another cause of mold is placing the seedling flat in direct sunlight or an excessively warm spot. The mold forms a crust on potting soil that water doesn’t easily penetrate and that blocks germinating seeds.
How to Treat Mold in a Seedling Flat
Removing the mold from a seedling flat risks harming the seedlings, but you can discourage it from increasing. Allow the surface of the potting soil to dry before watering again and reduce the amount of water you give the seedlings so that the potting soil is damp, not soggy. If the seedling flat is in a place where air doesn’t circulate, move it to an airy spot. But don’t place the seedlings in direct sunlight or in an area that experiences high temperatures.
How to Prevent Mold From Growing on Potting Soil
Prevention is the best cure when it comes to mold on potting soil. Removing the mold once it’s appeared is tricky and there’s a risk of damaging the seedlings’ stems. To discourage the growth of mold, use a potting soil that doesn’t contain compost or manure. Equal parts vermiculite and peat moss create a mix that holds moisture evenly and doesn’t form a moldy crust in sunny conditions. Compost and manure supply developing seedlings with plant nutrients, however, so in their place add a liquid fertilizer that’s suitable for seedlings after the seedlings have developed two sets of true leaves. Dilute and apply the fertilizer according to the manufacturer’s directions.
How to Sterilize Seedling Flats
Sterilizing seedling flats before using them helps prevent the spread of mold spores and dangerous plant diseases. Add 1 cup of household bleach to 9 cups of water to create a 10 percent bleach solution. Soak the seedling flats in the solution for 30 minutes, rinse them in clean water and then allow them to air-dry before adding potting soil.
How to Get Rid of the Mold Growing in My Seedling Flat. Many gardeners worry that the appearance of fuzzy white mold on the soil of their seedling flats means certain death to the plants. While it is a signal to change their environment, the white mold itself does not pose a danger to your seedlings. The white mold …