8 Tips to Prevent Damping-Off of Seedlings

The zeal of greens and other starts emerging from the soil, crisp and bright is something to look forward to. But sometimes our seedlings, even when imbibed with hope and expectancy, keel over before getting much of a start. If you find your seedlings are either not coming up or falling over and wilting near soil level they are probably suffering from damping-off.

Damping-off is caused by fungi that live in soil and is generally encouraged when seeds are over watered, crowded or seedlings are stressed due to factors such as incorrect light and temperature. Infected seeding containers, poor air circulation, overly rich or unsterile soil can also be factors.

Organic Prevention:

• Water your seeds when their first planted and then, after that, only enough to keep the soil moist. If the soil dries out it will interrupt the germination process but waterlogged soil will increase the probability of damping-off.
• Give your seeds room to grow and place them in an area with good air circulation.
• Follow directions on your seed packet or organic gardening guide as to when to plant, how deep to plant, light requirements and optimal soil temperatures.
• Plant in clean containers using clean tools and consider using sterile soil or a soilless seed starting mix.  Avoid mixes with peat moss, coir is far more sustainable.
• Try bottom watering your seedling flats or pots by placing them in a shallow bin of water.
• If you’re still running into trouble you can cover with vermiculite or sand to the specified depth instead of soil.
• Cinnamon and powdered charcoal act as natural fungicides. Try sprinkling the soil surface with one or both for added protection.
• Finally, follow the breakfast, lunch then dinner principle when planting and transplanting. Breakfast is for seeds, they don’t require a hearty meal but just enough to get going. (In fact, rich soil can burn seedlings as well as encourage damping off.) This is your seed starting mix, baked soil or soilless mix. Lunch is for transplanted seedlings. They’re ready for more nutrition to get to the next stage of growth which is ultimately harvest ready. Plants generally need an extra boost of nutrition just before harvesting in order for fruits, leafy greens, etc. to pack some punch and be as productive as possible. Add rich compost or other organic fertilizers as needed.

Having worked for years in school gardens where many of these measures are difficult to follow, mainly because of time, I’ve found if you simply don’t overwater your seedlings and grow them in an environment with good ventilation you’re already ahead of the game. But it’s always good to have a quiver of tools on hand, especially when you’re eager to get your garden growing.