Pictures would help.

Agree, wilting can be caused by so many things it is just guesswork without as many details as possible.

Are these plants the same variety, same sun exposure, different type (ind. vs det.) could mean very different root mass, abnormal weather, pest issues, what is the nutrient ratio of Dynagro as excess N can cause wilting and so can excess K, watering "schedules" whether the plant needs it or not can cause wilting if plants become water-dependent, etc.

Dave

Look at the nitrogen type. Like nitrate nitrogen x%, ammonium nitrogen x%.

That matters quite a lot. The latter should ideally be quite small if possible, or it will burn younger plants, and they will wilt a bit, if used regularly.

Why is it happening only to some plants though, you should try to see what is different about them.

I got home too late last night to take pictures but I did notice one thing that I never really thought too much of before. The wilting only occurs during the afternoon hours. When I went to look at the plants this morning before direct sunlight hit them they didn't seem wilted at all. This has pretty much been the pattern for most of July. Is wilting only during hours of direct sunlight a common occurrence?

Some softness in the young foliage during the hottest part of the day is sometimes normal. Stunted growth is not. But we don't actually know whether either is happening.

When you say "stunted", do you just mean those plants are shorter? Because some varieties are smaller plants than others. And sometimes, plants pause in their vegetative growth if they're heavily loaded with fruit, have recently been transplanted, etc.

And "wilting" can mean many things to different people. Are the leaves nice and stiff/turgid but just pointing or drooping down? Or are they limp and softer and "collapsing"? I think we really need to see pictures.

Also, stick your finger a few inches down in the medium when the wilting is happening and report back with how the moisture levels are. Cloth-type pots lose moisture VERY quickly. Unless you're somewhere very cool and rainy, I doubt every three days is enough water. And some varieties are more drought sensitive than others.

I have read that afternoon wilting can be normal because that is the hottest part of the day. If the tomatoes look fine in the morning, you are probaby doing okay.

you did not mention how big your plants are, or how big your pots are, but if
you're watering every 3 days, in a 5-1-1 mix that seems way too little, and then on top of that ,you have them in a fabric pot which means more water loss. a mature tomato plant can drink like 3 gallons of water per day easily..in the past, i have grown in hydroponics for many years, so i know a thing or two about tomato water consumption.

personally, these 5-1-1 mixes people talk about are not great for tomatoes, and i think its just over complicating container gardening. maybe for peppers, but tomatoes don't need that kind of drainage. the mix causes inconsistent moisture for tomatoes because they can drink so much water.. just my opinion. i'd probably wrap those pots with some plastic.

Wilting in sun/heat is NOT a common occurrence, unless the plants are thirsty. My plants never wilt unless they are. If you put a few drops of water on every three days, that won't be enough. I'd dig into the soil and see what the moisture level looks like a few inches down in different containers. Plants in containers will need more water than they would in the ground.

The ones I am having wilting with (and IMO stunted growth compared to previous years) are typically the cream of my crop....Lemon Boys and Cherokee Chocolates.

My test for whether I need to water or not is to insert my hand into the top few inches of 5-1-1 mix, massage it in my hands, and observe moisture content or lack thereof. Since the top few inches of the 20 gallon containers would be the driest I just figured this was a good gauge. Lately they mix has been adequately moist every time I've checked.

I'm afraid to over-water my already-wilting tomatoes since my other varieties are doing just fine under the SAME EXACT conditions. In other words I don't want to make them worse than they already are.

Keep in mind that some plants, even under exactly the same conditions, do require more water. I'm not saying this is the problem, but the numbers of fruit, plant size, leaf mass, etc... as well as even where the plant is located, can all affect water needs.

Here are photos of the 6 tomato plants next to the side of my garage. The affected plants are the two in the middle. The wilting this evening isn't as bad as it was earlier in the week. It could be due to the fact that I did a lot of pruning on Sunday when I returned from a 10 day vacation. I do that when the foliage gets too bushy in the middle of the plant.

Here are photos of the 6 tomato plants in the back of my garden in the backyard. Same type of behavior. Only my cherry tomato plants are thriving. The Lemon Boy, Big Beef, and two Cherokee Chocolates are mediocre at best.

Interesting, indeed, and I have had similar issues in the past with various plants. I definitely agree that wilting during the hot part of the day is not normal, as my garden gets brutal afternoon heat that can easily reach 110 in direct sun right up against my south-facing house. The plants always look good during the day. When my plants have wilted like yours, especially that last photo which, I never could determine the problem. I've seen very similar issues with various plants over the past few seasons. Same soil/fertilizer/water as everyone else, moist soil, nothing out of the ordinary. Sometimes plants just give in without us figuring out a good reason why. If you can, put in lots of plants to make up for those that don't make it. :)

In a well-draining mix in a fabric pot, waterlogging of the roots is unlikely in July in NJ. I agree with Dave--water them really well and see what happens.

If they were in-ground, I'd suspect bacterial wilt or something, but in a growbag-type container with fresh mix, water is the most likely culprit.

OK, I will water heavily every other day until I see a change.

How (method) and how much is just as important as watering. So how much water are you planning to give them every other day and how do you deliver it? Some water is not the same thing as enough water and different methods deliver water more effectively than other methods.

For example 1 gallon of water isn't nearly enough for that size container and 3 gallons with a hard fast pour or a high pressure hose may not be enough either.

Dave

I would water them really well a few times until water runs out of them. If too much nitrogen is the problem, it will partly get washed, and the problem should improve.

I don't think the lack of water per se is the problem, if they are all watered the same. From my growing in containers the bigger plants are always the ones to wilt first from lack of water (which is normal), and the second is how hot those containers get, even if they are moist. I assume the hot medium is limiting the roots' ability to function well.

Never had a problem with wilting before in 4 years so I doubt the containers are too hot for the roots.

I always water them heavily with each watering. When I say heavily I mean until water seeps out of all sides of the containers including the bottom. Probably about 2 gallons of water per plant.

Not sure how anybody else waters, but when watering, I add a little water to a plant... add a little water to the next plant... add a little water to the next plant... etc... then start back at the beginning and repeat until time to stop. I find that adding a lot of water at once doesn't moisten all the medium. The water simply follows the path of least resistance and flows in a stream. Adding a little at a time allows the medium to saturate fully and the roots to make full use of the moisture, and thus the present available nutrients.

Well, what happens when you water them? A plant that is wilting due to lack of water will typically perk right back up within an hour of being watered well. If it doesn't, then the issue is probably not watering.

I doubt that 5-1-1 mix or any soil less mix will carry soil borne fungus to cause wilting.

The 5-1-1 mix does NOT retain much moisture. So you have to water them more frequently, depending on how hot it gets, how many hours of direct sun hits them. The black containers also can be a contributing factor, by absorbing heat and not radiating it. JMO

njitgrad: Never had a problem with wilting before in 4 years so I doubt the containers are too hot for the roots.

Just because things were fine before doesn't mean they're going to be fine now. Conditions differ every year. If you make your 5-1-1 fresh every year, there could be a difference in the particle size/absorbency of the materials you use, etc.

I always water them heavily with each watering. When I say heavily I mean until water seeps out of all sides of the containers including the bottom. Probably about 2 gallons of water per plant.

It depends on the rate of watering. If you dump a lot of water quickly, much of it may run off without hydrating the mix properly. Also, if the mix is getting too dry in between waterings, it doesn't matter how much you water when you do water. 5-1-1 is a well-draining mix, so it won't hold onto a lot of water. It's not like growing in-ground. So excess water does nothing, just drains away. The key is enough water at the optimum frequency. A ton of water but not often enough will still lead to drought stress if you're growing in containers with a well-draining mix.

I understand that it's frustrating that what you did before is not having the same good results today, but it doesn't really help your plants to reject advice because what you were doing before worked before. It's obviously not working now for some of your plants.

Yep. What gb said.

Dave