We’ve all been there; hope and optimism-filled as we sow seeds, only to be crushed a few days or weeks later as our they either fail to emerge, or (even worse) sprout beautifully and then suddenly collapse for no apparent reason.
The culprits are both fungal and soil-borne diseases, and there are many of them – hence the collective term. The good news is that there is a lot you can do to prevent damping off.
Improving the air-flow to your seedlings is absolutely critical; remove any covering over your seeds as soon as you see action (individual pots which can be moved as soon as the seedling appears are preferable to trays). If trays are used, don’t wait until all the seeds have germinated; get that lid off at the two-thirds mark.
Make sure that your seed mix is sterile, and well-drained. Get some fine horticultural grit and mix it 50/50 with your seed compost – this will keep air-flow and drainage at good levels.
Ensure that you water really well, but do it from below, standing your pots or trays in water until the compost has absorbed the moisture it needs, and then pouring away any excess.
Make sure that your containers and any tools you use are as sterile as possible. You can do this by washing thoroughly with hot soapy water, or if you want to be totally sure, then you could even zap your pots in a steam steriliser - a bit over-the-top perhaps, but if you’re going to the effort of growing from seed, then it might just be worth the bother.