We have a problem every year in our greenhouse with any of our climbing vines (cucumbers, melons, squash, etc) and stem rot, called Fusarium Stem and Root Rot. We live on the coast where it is damp and cooler than the interior, so this is a common problem.
So I have experimented, the last couple of summers with different ways of dealing with this fast spreading disease, and have come up with something I feel is quite effective.
As someone who tries at all costs to stay away from commercial pesticides, fungicides, fertilizers, and such, I was trying to find something that is easily accessible to everyone, cost-effective, and garden friendly.
And here it is, drum roll please: hydrogen peroxide. Yup, the stuff you buy off the shelf at the drug store. It is great for killing funguses and moulds, not to mention viruses, bacteria, and the like.
So aside from trying to be very careful about sanitizing thing like the greenhouse scissors, my hands, tools, and such to help slow the spread, I got rid of vines and leaves that were already yellowing and obviously not going to make it. I put the hydrogen peroxide in a spray bottle, straight up (here in Canada it’s a 3% solution) and sprayed it on any areas of the remaining vines that were starting to show rot. Last year I tried diluting the hydrogen peroxide with water, but didn’t feel it was strong enough.
So this year I put on gloves (you want to do this in case of back spray onto your hands, hydrogen peroxide can sting the fingers!), marked the bottle clearly, and so far the results have been impressive.
Morning and evening I have sprayed these areas for the last few days, and most areas have cleared right up leaving a sort of brown scab, or dry spot on the healed area. But the vines are fine, producing well, and of course, there’s the odd new spot that pops up with the fungus. Continual vigilance is necessary.
However, with hydrogen peroxide, I spray all the tools, scissors, greenhouse walls and frame (you can dilute it for this of course), and so far it is working well!
So I thought I would share, in case you are looking for help with this problem, or, if you have discovered a solution to this problem on your own that might help us out.
Happy melon growing!
Disclaimer: Please note that this article is only the opinion of the author, and is a result of her own experience. Results for others may be totally different. All precautions should still be taken to keep things like hydrogen peroxide out of reach of children and pets, and labels on bottles of hydrogen peroxide should be read and followed.
) in to help hold the cover up off the ground. You don’t really need to, but I like to, I find it’s easier to deal with when its not stuck in the dirt all the time. 
