Damping off

Damping-off is the name given to several types of fungi which attack young seedlings at soil level and rot the stems. The disease spreads quickly and cannot be cured, but it can be prevented.

Symptoms:

• Poor germination.
• The stems of young seedlings narrows and blackens, while the leaves above appear healthy. The entire plant soon topples over and dies.
• The disease tends to move in a circular spreading pattern moving from one plant outwards to infect the rest, often wiping out a whole tray of seedlings shortly after appearing.

Prevention:

• Use sterilized soil-less potting soil when starting seedlings, never garden soil which can harbour diseases.
• Grow seedlings in a warm environment. Use a heat mat or place plants in a warm place like on top of the fridge.
• Use clean seed and clean containers with holes in the bottom.
• Special seeding trays are available which have a number of parallel gutters into which media and seed are placed - damping-off organisms do not generally cross over the high plastic lips between gutters.
• Prevent overcrowding by sowing seeds according to the spacing on the seed packet.
• Cover seeds with a thin layer of a sterile media such as vermiculite.
• Remove the plastic cover from your seedling trays immediately after seeds germinate.
• Provide good lighting after germination.
• Place a fan in the room to increase air circulation.
• Thin to one plant per pot after germination to prevent overcrowding.
• Do not over-water and avoid watering in the evening or at night.
• Transplant seedlings once the true leaves appear to give them more space.

People ask us if cinnamon works to prevent damping off. There is no scientific study to show that cinnamon works and therefore there is no recommendation about the amount of cinnamon to use. Use the prevention methods listed above. However, if you choose to use cinnamon, it would likely do no harm.