The General Sherman, a Giant Sequoia tree, stands 275 feet tall and the base of the trunk has a circumference of over 102 feet. But even this towering behemoth is dwarfed in volume by another living creature, in eastern Oregon, that lives under 2,200 acres of forest. This is a fungus that grows honey mushrooms.
Funguses (or fungi) such as mushrooms are eaten as food, but fungus also leavens bread, ferments beer and wine, and is even used to produce antibiotics and pesticides.
But in gardening, fungus can also be a killer. Damping off is a catch phrase for several funguses that can kill emerging seedlings. Seeds can become infected with a fungus, sometimes making the seeds dark and soft. This can kill the seed before it even sprouts. More commonly the seeds will sprout then mysteriously thin right where the stem touches the ground, until the stem rots, falls over and dies.
Damping off usually only attacks very young seedlings. After your plants have mature leaves and a good root system, they can naturally defend against the damping off fungi.
Damping off fungi can survive on plant debris, seed flats and pots and even opened bags of potting soil. Always use new fresh potting soil and disinfect all tools, pots and planting trays with a solution of one cup of chlorine bleach mixed with nine cups of water.
An all-purpose houseplant type potting soil can be used for starting the seeds. Do not use soil from the garden unless it has been sterilized first. Otherwise you are apt to introduce weeds, bugs and disease to the seeding mix. You can sterilize the soil in the oven by baking it for about two hours at 170 to 180 degrees.
Fill your potting containers up to the rim, so they are overflowing with soil. This allows air to flow across the soil surface and helps control of damping off disease. Some growers actually install fans to gently circulate the air.