You used logic on FB? 😂😂😂.

LOL. Fair enough, Sherry!

What helped me was three things; mulch the dirt with straw or pine straw that was new every year, cut the lower leaves off, and move the tomato bed every year.

ETA: I also watered early in the day, so everything could dry by noon. Yes, I used a sprinkler. If it rained, great, I did not worry about what time! What are they doing, running out with a hair dryer to dry the leaves if it rains?

I'm not sure how much of a controversy it is but the preferred way to water tomatoes is at the roots, ideally with drip irrigation. That is the way even commercial tomato fields are irrigated.

But you can't stop rain from falling and water on the leaves is not an immediate kiss of death. If faced with days of endless rain, I would rig up some sort of temporary covering........otherwise I would just ignore.

One of the things you discover if you are a lifelong gardener who has moved a lot is that so much gardening advice is from people's experience and that experience is based on their climate. What diseases are prevalent in your area is a function of your climate. "Disease resistant" varieties may be resistant to diseases not commonly found in your area. For example, diseases that show up in scorching hot summers is not a problem I've ever had, diseases that show up when there are too many cold, damp nights are.

Your gardening practices will make a huge difference. Rotating your crops is a big plus, but some of us who like to grow lots of tomatoes in little community garden plots may not be able to do that. I'm careful to plant at least a few tomatoes with resistence to early and late blight --- the diseases common to my area.

But take advice from someone who lives in a different climate carefully. They might be the world's most experienced tomato grower for their climate, but not yours. The big issuse for climate is often the most extreme days ---- the really hot days or the cold nights. One or two way too hot days or way too cold nights. The rest of the summer might look pretty similar in one place and another.

My personal preference is to use watering ooze hoses covered with compost to water all my veggies. Here we have a deep well for that purpose which I see as better than using city water, cheaper too. I never water via overhead sprinklers unless an ongoing drought is so bad that the plants need a good rinse to clear their foliage/pours. This is especially true during tree pollen season when the plants are coated with smothering pollen, esp pine pollen that can be as thick as a coat of paint here. But I'd only do this in the early morning to allow the plants to dry out quickly.
As for rain, a perfectly situated garden would get direct sun at dawn to quickly dry things out and some late day shade to keep the plants a bit cooler during heat waves. Nothing beats a good rain to invigorate a garden. All that being said it's sometimes impossible to escape blight/fungal related diseases no matter one's growing conditions, plants just get old in dew time ;-)

Agree, Sigrid, that gardening is very location dependent. I guess what I was sensing on that FB group was an overall lack of perspective and moderation in sharing opinions, especially in a common-interest forum where folks want to share their ups and downs, and newbies are trying to learn from others' experience. It seems these days people are so rooted in their beliefs - whether gardening, politics, diet, or what Aunt Mary wore to the family reunion - that they double-down hard on their opinions as the only truth.

We're in a drought - my tomatoes and I would welcome a few days of rain!

Location is all. I don't need to water outdoor tomatoes. Rain is all the water they get. And yes. Most years they get blight eventually. Really I just grow them for fun. The harvest is barely worth having.

"Nothing beats a good rain to invigorate a garden."

^^ This. I don't want days on end rain, or worse days on end rain and chilly weather during summer (it happens where I am some years...), but a good soaking rain 1-2x/week is perfect. Then I don't have to water at all, and yes IME the plants respond better to rain. Sometimes disease is inevitable, your best bet is to plant resistant varieties and practice good plant hygiene (good air circulation, prune off lower leaves, pick up any fallen leaves off ground, etc).

All the rain is certainly invigorating my grass and the weeds!

I love the sound of rain while napping.

Drip or soak is preferred, but overhead watering in the day with enough time for the leaves to dry out is also OK, spores need wet leaves to germinate. Millions of fungal spores are released from other sources all over the area, and while spores in the ground under the plant can be suppressed, you're not going to stop the wind from blowing in spores. Septoria leaf spot needs 24 to 48 hours of wet leaves to germinate, and Early blight needs only 5 to 11 hours of continuous wet leaves to germinate. No one can stop the rain.

The more people scream the less they understand. By applying a thick layer of mulch under the plants it will stay wet to long and rise the humidity under the plant creating a micro climate of high humidity, long enough to allow spores to germinate. If you mulch keep it below an inch thick for quick drying, but one thing nearly all people DO NOT understand is the importance of fertilizing. And I will cap DO NOT!

Incorrectly fertilizing the plants will weaken it, and what fungus loves the most. Incorrect fertilizers, lack of, or wrong balance will strip the plants own defense to fight disease. Potassium thickens cell walls, regulates stomata to block spore entry, and powers defense enzymes. Calcium solidifies the pectin cell wall glue to act as a physical barrier against fungal enzymes. And the one people rarely think about is Sulfur!

Sulfur, in the form Sulfate is the core nutrient responsible for providing fungus resistance in plants, it triggers natural defense mechanisms known as Sulfur Induced Resistance, which is the plants chemical defense against fungus. Together with potassium and calcium this is what gives your tomato plant"s resistance against fungus attacks. Watering from below may delay the germination but a full long day of just light rain in the right air temperature window and your plants are doomed without the plants own defenses.

And a few tidbits about sulfate. It doe not hang around in the soil, the one and done approach does not work. Sulfate is highly mobile and leaches down quickly. Trust me, I've ran the numbers. You can load the soil full of Calcium sulfate (gypsum) and Potassium sulfate before you plant, and if the transplants don't die the sulfate is 3 foot down in 17 to 28 days at even excess and nearly toxic levels, depending on soil type and water volume. (rain, watering). Has any on the facebook group ever said I need to feed my plant more sulfate? I don't think so.

A lot of sulfate isn't needed, and on a biweekly schedule only 1.2 grams per square feet under the plant is needed to maintain the sulfur requirements. Sulfate comes as the second part of compound fertilizers and not hard to achieve. But the problem is it leaches fast, and the 1.2 grams will drop a foot with an inch of watering. Sulfur is not mobile in the plant and something that is not stored or moved around to be used with new growth. Take some of what I wrote and go back to the facebook group and start yelling at them in caps!

Doesn't rainwater contain nitrogen?

Rain sure does contain nitrogen, but not much. The amount from an inch of rain fall would equal about 1 ppm, or about a 1/4 pound per acre. About a quarter of this is nitrates, a quarter ammonium and the other half is organic nitrogen. The nitrates flow through the ground with the water and lost to leaching, the Ammonium is converted into the nitrates taking about a week which is also flushed out during the next rainfall. The organic nitrogen is converted to ammonium and then to nitrates, and takes many weeks to months to years which has the same decomposition requirements as any organic matter including cats and dogs.

But the amount of all three types of nitrogen isn't enough to grow anything substantial but is enough to grow native grasses, wildflowers and weeds because they've evolved to grow in low nutrient soils. Buffalo can survive eating native grasses, flowers and weeds but we can't, so It takes an average of 150 lbs of nitrogen per acre to grow corn. This would require the rainfall of over 1200 inches of rain in a growing season to achieve this amount of nitrogen. Lesson learned here is do not fertilize your wild flowers, they will die.

outpaitentzero said "Do not fertilize your wild flowers,they will die."

Which is true and brings use full circle back to tomatoes which also suffer if too generously fertilized. I've experimented and it's eye opening to see how production goes down once soil has adiquate neutrients then more are added. What's a person to do? Pulling soil tests give best indications but some can't afford ongoing tests. Relying on organics as source of neutrents rather than synthetics affords a measure of "wiggle room". Reason being that plants tend to take what they need and leave excess organic neutrents in soil.

This discussion started with improper watering promoting disease. Lack of certain micro-nutrients is also known to increase risk of disease,excess of others do the same. All together it's enough to make one think of pulling their hair out! (:

.

Wait, so I'm supposed to plant a cat, or a dog, under each of my tomatoes?!

Good grief, this is getting complicated!

A cat for determinate plants and a dog for indeterminate if you want to be picky.

No,no,no, if it happens to be raining bobcats and St Bernards they would be overkill under tomatoes. Besides that noone wants to work in the rain. As I mentioned, old_dirt 6a over on Soil Compost and Mulch forum has it worked out to a science. Actually there is one situation where one dog for one plant is the perfect answer. It involves a neighbors dog persistently killing your chickens. It's called sss.

I agree that my plants do better with regular rain showers than with any "artificial" watering methods. However, I've been using overhead sprinklers now for about 50 years and have not had a problem with blight outside of one year. I also don't fertilize other than composted cow manure, which my cows keep providing me with copious amounts of.

Of course, I also dig a hole, plop in a shovel full of composted cow manure, stick a tomato plant in and walk away. It has always worked fine. Last year I tried to save my 71 year old back and used the Florida Weave, it was time consuming, aggravating, and my tomatoes laughed as they pulled those t-posts over. This year I'm going to try to grow them up cattle panels and if it doesn't work, it's back to throwing a plant in a hole full of cow manure and walking away! My back will have to deal with it.

All that to say that I'm not going to change to drip irrigation now, overhead sprinklers have always worked fine and rain is the best option of all.

Annie

I think thick hay or straw mulch helps prevent diseases better than keeping leaves dry. Municipal water often has chlorine in it however, so there's that.

FWIW, recently I was rooting some mint in distilled water and when I added tap water, the healthy white roots started turning brown and leaves started to drop. When I replaced the tap water with distilled water, it started growing with healthy white roots again.