I think it's a matter of you can't stop the rain, but you
can stop watering from above.

Creedence Clearwater Revival did Who'll Stop the Rain,
by the way.

I'm sure I'll catch some flack for what I'm about to say,
but I do water from above very often. As a disclaimer,
I live in Southern California where it's quite dry. I was
told by Steve Goto, a wholesale grower and all around
good guy, that here in SoCal, we can get away with it.
The reason is that the dryness will not let the bad stuff
get started. And in addition, overhead watering will
wash off all those bad things from the plants, so that will
further help in keeping disease at bay.

I do mulch heavily too, and that also helps to keep the
diseases that are in the dirt from splashing up onto the
plant. Of course, that assumes the diseases can't live
in mulch and only in the dirt.

But primarily it is because wet foliage only encourages both bacterial and airborne fungal diseases to set in and infect the plant.

Of course you can't control the rain - not that that is an issue for many of us in the summer anyway :) - but you can easily avoid overhead watering and so improve the odds of healthy plants for the long haul.

Dave

And I'm glad to see someone else agrees with me. I thought
I'd get lambasted. But then it's early in the thread life.

I too prune heavily and use cages to keep the resulting
4 main leaders close together in the cages. No problems
with my method for the last 20 or so years.

Thinking about Dave's comments about shallow watering and
the resulting shallow roots, I think that the soil type
I have may obviate that problem. It's caliche and water
just runs into the ground and goes deeply in no time at
all. I keep a close eye on my soil and many times when
the top is dry, a few inches down, it's quite moist. Never
had a problem with shallow roots.

I think my growing situation is outside the norm.
For most folks, Dave's right. I'm just a little different.
Something my wife keeps telling me. Only she says I'm
more than a little different.

Raci I'm just answering your question as to why. They are your plants and your water. Same goes for all the pruning you apparently do. :)

But with all that rain I'd wouldn't think you'd have to water them much anyway. I don't envy you all that rain and humidity. Diseases are bad enough here where it is dry.

And it strikes me a much more work than just using soaker hoses and they eliminate the water wasting. So what's the big advantage?

Dave

Yes some pesticides can kill bees and other beneficial insects so need to be avoided. But no, bees are not needed for pollination with tomatoes. Tomatoes are self-pollinating but wet pollen isn't viable.

Yes you could use the time to check for bugs while standing there holding a hose but pest patrol is a daily activity and watering tomato plants every day would be way over-watering. If I waited until the weekly watering most plants need to check for bugs all the damage would already be done.

Dave

There is some pretty interesting research out there that talks about how lightening is powerful enough to break apart the nitrogen so that it is available to the plants. You aren't getting that from a garden hose.

Also, most rain showers are accompanied by wind, which helps stimulate growth and dry the leaves.