‘Damping off’ diseases, shown by a whiteish furry fungus on the base of the seedlings at soil level, are usually caused by too much moisture on the soil surface.
Although the excess moisture is the cause, the fungal disease which results can rapidly spread through the seedlings. You will be able to see this as the stems grow weak and spindly at the bottom. The seedlings will be unable to stand up without the stem’s support.
Many gardeners advise putting a plastic cloche or covering over seedlings to retain moisture. This is actually the worst thing you can do! You want the surface of the soil to be dry and the moisture to be at the bottom, which will also encourage root growth.
Ok, so to this end, the seedlings need to be watered from the bottom not the top
The easiest way to do this is to stand the seed pots/trays/cells (make sure they have holes in the bottom) in something you can add water to. An old baking tray or plastic box is ideal for this purpose.
Individual seed cells or seed trays with separate sections help to prevent spread, because this enables infected seedlings and soil to be removed quickly.
Don’t cover the seedlings. If you think it’s too cold move them somewhere warmer, which is why a greenhouse, porch or indoor window sill is perfect.
And last, back to the cinnamon!
The use of Cinnamon in gardening has anti-fungal properties, good for our health but great for plants too.
And, this use of cinnamon can be applied to indoor plants in the same way.
It’s also thought that cinnamon helps to deter insects, and cinnamon oil can be used to kill mosquito larvae.