Is this damping off

[Labradors2]

I grew cukes in DE in pots made of newspaper. They did much better than the seeds that I grew in potting mix and they transplanted beautifully into the garden.

Linda

[RayR]

Originally Posted by KarenO

...I don't see how those can be transplanted without disturbing the roots which will kill a cucumber seedling virtually always. If I start cucurbits indoors I always use peat pots so they can be planted pot and all with no root disturbance. ut DE a Forgive my old school ways bnd Peroxide etc. seems so unnatural and I think since the high tech methods are not working for you I would recommend a step back to the natural formula: seed+ soil+ water + sunshine= cucumbers
In June, even in Northern Canada, cucumber seeds will grow fine if planted right into warm soil in the open garden. If you wish to start them indoors, sterile potting medium, moist not wet in peat pots and transplanted pot and all as soon as they have one set of leaves.
I don't understand why all this artificial business is necessary?
Maybe I am missing something
Just an opinion from an old school master gardener from Canada
Karen

I don't like the idea of disturbing the roots of cucurbits either, that I agree with.
About the only use I have for peat pots and the like is for starting cucumbers and squash indoors.
Only a few people have reported damping off in DE as a seed starting medium which makes me wonder about the source of the inoculum. Is the pathogen seed born or are the spores just prevalent in the environment. Air borne or water borne? It has to come from somewhere whether it's fungal or an oomycete.
DE is no more artificial than perlite or vermiculite, maybe even more so since it doesn't have to be altered with high heat to make it usable.
Most people who have been plagued by damping off pathogens over the years have reported much better results from DE which hasn't surprised me since using silicate materials is an old school method of retarding damping off. Other silicates like coarse sand and bird grit are used on top of seed starting mediums by some folks including one long time commercial greenhouse herb grower I heard in an interview on the Internet. Many hydroponic growers also use Potassium Silicate in part to ward off damping off.

If using a safe mild diluted oxidant like Hydrogen Peroxide helps to kill pathogen spores on seed or in the medium, I don't see any harm in that.