New topic/ seedling damping off

Jane McGary
Fri, 30 Dec 2011 15:43:19 PST
At 11:28 AM 12/28/2011, you wrote:
>I'm curious to know  how other seed sowers handle the problem of
>damping off.
>I use  a high content of pumice in my mix  so that  the mix dries out
>relatively quickly.    I also have sterilized the soil, but ,
>unfortunately,  besides killing pathogens, it also kills beneficial
>All seed containers are soaked in a Sodium hypochlorite / H2O
>solution  before being used.
>Here in the Pacific Northwest, even under cover, a seed pan can stay
>moist  for a long time, which can be a problem.

I also live in the Pacific Northwest. I don't sterilize the seed soil 
mix because I assume it will soon become non-sterile just from the 
atmosphere. I also use a lot of pumice in the mix, but no soil, just 
pumice, coarse sand, and peat. I don't wash the sand, so it holds a 
fair amount of moisture, and I cover the top of the pot with grit to 
keep the moisture level more consistent.

The best ways I know to avoid damping off of bulb seedlings are (1) 
do not plant the seeds too thickly, and (2) keep the seedlings as 
cool as possible while avoiding freezing. Indeed, some genera even 
tolerate light frost at this stage. The cooling option would not 
work, however, if you are growing tropical-climate bulbs.

The main bulb genus that I've had trouble with in terms of damping 
off is Calochortus, and only when I put too many seeds in the pot.

Jane McGary
Portland, Oregon, USA

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