Should I spray my cucumbers with a fungicide?


#1

I’ve always considered cucumbers short lived and have never sprayed them. Maybe I should. It seems like I get about two weeks of good production and they start dying. In about another two weeks it’s over. Can I do better?


#2

Looks like bacterial wilt to me. Your best options are to plant resistant varieties and/or control cucumber beetles (which spread it). Never spray any pesticide/herbicide/fungicide unless you know what it is you’re fighting and whether the product is effective against that issue.

https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/bacterial-spots/bacterial-wilt-of-cucumber.aspx#:~:text=Cucumber%20bacterial%20wilt%20is%20caused,rarely%20a%20problem%20on%20watermelons.


#3

For us, cucurbits coming down with powdery &/ downey mildew is pretty much a certainty. It’s always wise to spray antifungal as a preventative rather than wait for the inevitable. Same thing with tomatoes.

Cucumber beetles is also a certainty and needs to be dealt with before wilt sets in.


#4

Looks like downy mildew for the most part. Leaves flag and collapse as the diseases progress. If you have any healthy foliage left, applying a safe fungicide such as potassium bicarbonate every few days might slow progression and extend season. Be sure to spray well—especially undersides of leaves. (Edit: Agree that prevention is best. Early and regular applications of neem oil have helped extend my cucumber harvest in the past; it has some fungicidal activity and also offers some control of cucumber beetles.)

You can also try resistant cultivars. Dar has performed well for me this year; and has shown admirable downy mildew resistance. It is not resistant to bacterial wilt, however. Arkansas Little Leaf is supposed to be resistant to both downy mildew and bacterial wilt. Controlling cucumber beetles, btw, is not only important for controlling bacterial wilt: they also cause higher incidence of diseases such as downy mildew by carrying spores and stressing and wounding plants.


#5

You might consider succession plantings. A plant planted 2 weeks later might not buy you a full 2 weeks extra, because disease and pest pressure will take later plantings down quicker, but it should still buy you something.


#6

Graftman,
I planted 3 different cucumbers this summer. One in a fabric pot . . . and the others in tall plastic planters left over from ‘porch’ plantings. I didn’t care for the two in the plastic containers at all . . . and when they started to look like yours - I pulled them out.
But . . . . the one in the 15 gal fabric pot is still going strong! I think the difference was the variety, but I could be wrong. It is a ‘Sweet Slice’ - and they are GREAT!

The other two are ‘Green Crisp’ and ‘Burpless Beauty’. Both were disappointing. Dry and not sweet at all. Rather tasteless, actually. A waste of time - and space.

My cucumber experience has been much like yours, in past years. They start off strong and peter out pretty quick. This year I did spray for the ‘usual stuff’ - the mildew and the beetles. Never saw a single beetle . . . but the mildews and the wilt finally won out in spite of the spray. But - not with the Sweet Slice! Perhaps it is much more resistant.

I highly recommend it. Great cucumber.


#7

Thanks for the responses. One thing to note is the leaves don’t wilt just get spotty and dry up. I thought possibly it’s anthracnose. Or maybe it’s old age and they just don’t live that long.


#8

One other thing, That picture of a digital display was an accident. I’m not trying to promote anything.