Clearly you need to talk to the friend and ask exactly what she did and how often she did it. That info is where all the clues to what happened will be. Mainly did she water them at all?

What you are seeing now could be the result of many things - no water, way too much water causing the roots to rot, pests such as spider mites, diseases such as early blight, etc.

A lot can happen to plants in 5 days of little to no attention and something obviously has to these.

Meanwhile strip off all the dead leaves and branches and watch and hope for new growth.

Dave

Thanks, Dave! Should I continue to water/fertilize? It's raining here today so I won't need to water today or tomorrow. I did fertilize with Tomato Tone right before I left, do you think maybe I put too much on or put it too close to some of the plants by accident and they got burned? I used the recommended amount for established plants, but maybe I got a little too close.

I looked at them this morning during the rain and some of the leaves/branches are still wilting so maybe they are getting too much water? The sky is overcast and it was a nice rain so I can't imagine they would be wilting from dryness/heat stress at that time!

Follow-up: the yellow pear is dead. Everything wilted and there is no new growth. I haven't dug it up yet b/c I'm waiting another day or so for the fruit that's on there to ripen.
Similarly, the Black Prince is looking terrible too. Almost completely defoliated and the new growth out of the top looks diseased. Once those fruits ripen I'm pulling it too.

The Celebrity and the Better Boys lost a lot of foliage, but their new growth seems ok for now.

My husband made an interesting observation. There is a flower bed adjacent to my vegetable garden that has a sedum groundcover and that is looking dead too - and that stuff is indestructible! The outlet pipe for the basement sump pump is near the gardens. With all the rain we've had, there was a lot of basement water being pumped out. Perhaps something in that was funky?

I've had the same problem this year with my basement. For weeks all I could think of was "A River Runs Through It" or "Waterworld". :-)

Tomatoes hate being waterlogged. Moreso than most plants.

You could always stick your finger (or a stick) in the ground it see if it's soggy down around the roots. Or, if you pull up one of the plants, check to see that the ground is not waterlogged around the roots. If it is, that is likely the problem.

I doubt anything leached from the roof into the water and killed the plants.

We are down to some of the most likely suspects:

1. Water - way too much or way too little.

2. Herbicides -- either sprayed nearby and drifted unto the plants, or in the manure (or soil, if brought in). However, I would expect to see deformed and stunted foliage prior to death. Looking at the dead leaves, it's hard to detect any distortion in the foliage. The wilting leaves don't look distorted.

3. Disease. There are several diseases that can cause wilting, but disease is not obvious from the photo.

Afterthought: Since your sedum looks unhealthy also, did you use cow manure on that too? Many farms use pasture pesticides that pass right through grazers' digestive systems and into the manure unchanged. Then we take the manure, dress our gardens, and it causes our plants to die or at least struggle.

When getting manure or soil or compost, it would probably be a good idea to ask which pesticides they are using in their pasture. Then use accordingly. Link to an article below - just in case it applies to your situation (which is hard to discern).

Here is a link that might be useful: Herbicide Carryover

Was the basement water runoff from the roof/downspouts too? Or mainly groundwater?

I do believe that the new roof (asphalt shingles?) could have something to do with it. Warnings about not using rainbarrel water for drinking have mainly been concerned with microbial contamination, but with new petroleum-based shingles I'm sure there is chemical contamination as well. In a study from TX, they found contamination was worst in the first flush for all roof types, didn't test for petrochemicals but lead, iron and other metals were elevated and pH of runoff water was higher than the rainwater itself.

In their test of full-scale residential roofs, the youngest roof was 5 yrs old however. I don't know of a study looking at brand new roofs.

There is a list of toxic chemicals they did find in the samples from the residential roofs - many of these (like 2,4D) would be environmental and not due to the materials. It is interesting, however, that when they surveyed roofing professionals, the consensus (see page 50) was that asphalt shingles were NOT recommended for rainwater collection. More than 80% of contractors recommended metal for that purpose.

Of course, this was looking at drinking quality but you should water vegetables with potable water. I don't know of any studies that looked at the effects on plant health.

HTH

Here is a link that might be useful: TX Water Board study on roofing materials for rainwater collection

This article from NC State mentions "herbicides commonly used in roofing materials to prevent root penetration" so that could be a problem with the new shingles.

Here is a link that might be useful: NC State article on rainwater collection

lionheart - the manure came from a friend of mine. She only has one cow, and she doesn't use any chemicals in her small pasture. I did not use the manure on the sedum, but I used it on all 20 flower pots on my deck and all of them are fine. I also used it when planting zucchini and jalapeños in the same bed as the tomatoes with no issues.

ajsmama - the water from the sump was all groundwater seeping up in my basement. I stopped watering my vegetables with the rain barrel water but it doesn't seem to have helped.

I dug up the yellow pear today. The ground didn't seem overly soggy, but it hasn't rained in a few days and it's been over 90 every day so I'm sure the plants are taking up the water. I did cut the stem at the base, a photo is attached. Not sure if the brown around the outside is indicative of a disease?

One of my thoughts was that the roots may have been mechanically damaged by too much water or gnawing critters, such as voles or ground squirrels. That would cause wilting and, depending on how much of the roots were damaged, it would cause yellowing and a fairly quick death.

But I'm guessing the roots were plentiful and well-established, not short and not stubby.

Dave is a smart cookie. Spider mites are a possibility. Sometimes you can tell they are there by the little webs that appear on leaves. You might think the webs are caused by friendly garden spiders, but it could be spider mites.

The mites are pretty tiny, so you might need a magnifying glass to see them unless you are really young and have excellent eyesight. They can do a lot of damage.

Powdery mildew and downy mildew could also cause these problems, as can a number of other diseases. But we like to eliminate environmental/mechanical problems before thinking about diseases unless the signs are really obvious.

You could probably google powdery mildew, downy mildew, and spider mites to see examples of what they look like and the damage they can do.

In your last pic, the pith looks nice and green. I don't know if the slight browning in the vascular area is normal or not.

You may want to take a specimen to your local cooperative extension and see what they have to say, or give them a call and see what they have to say. They will be familiar with local gardening issues and disease pressures.

Just one other unlikely thought (although it's happened to a number of people on these boards) - these aren't planted near a walnut or butternut tree by any chance, are they?

Hmmm, the mildews don't look quite like my leaves, but the spider mite damage does seem like what is going on with my Black Prince currently. There is definitely something bad going on with the foliage that I couldn't identify. I'm going to do some investigating when I get home tonight! I'll try to post another picture.

Oh, and lionheart, there aren't any walnuts or butternuts around.

Yep, looks like spider mites!!

Those annoying little buggers! They can do a lot of damage. I hope you get revenge on them. :-)

I'm glad you have an answer. You've been very gracious in entertaining all of the possible suggestions.

Good thing you identified it as something that was not your friends fault!

Betsy

I appreciated all the suggestions, I was stumped!
Now I need to determine the best way to control them and salvage what's left of my plants!