Question
I have got to tell you that all these sites you recommended are great. I think I have more than one problem with the tomatoes and they are:
1. Powdery mildrew
2. Alternaria canker
3. Some early blight
Preventative measures for all of these diseases seems to be some sort of fungicide spray eary on, drip watering and to your point, rotation, rotation.
One other point I did not mention is that for the last two years I have not been able to grow eggplant. Prior to that I used to get robust plants. Now the plants turn yellow immediately following planting and never establish any sort of growth. I do believe whatever is attacking the tomatoes is getting to the eggplant. Just for kicks I planted 6 eggplant in a remote area of my yard and they are doing just fine. The 12 plants in my garden next to the tomatoes died and I had to remove. I have to assume the fungus attacking the tomatoes is also killing the eggplant.-------------------------

Followup To

Question -
Me again on the tomato issue.
By-the-way my name is Mike. Great sights and although many of the diseases look alike I think what I have may be a combination of Early blight and Septoria Leaf Spot (fusarium wilt is a maybe).
Most of the sights recommend similar prevention methods such as not watering from overhead as I do with my system and perhaps not planting tomatoes next year or just move my garden somewhere else on my property(hard to do).
One other question I had is that I use a ground cover to prevent weed growth. Do you think this may cause the ground to stay damp causing a root problem.




Answer -
I agree, Mike, you would have a best seller on your hands if you could have talked to your Italian gardening ancestors about their techniques.  Especially w/ something like tomatoes, which (a) everybody grows, and (b) are SO Italian. Martha Stewart would have you on the show.  You would be famous.  And I would be asking YOU for help with MY Tomatoes... or at least I would be telling everybody to watch your HGTV show on Sunday afternoons...

Well, what a pity, hindsight is always foresight.

You know about crop rotation, Mike?  You know why it works?  Diseases never have a chance to build numbers that would devastate a single plant, but are like a small blemish on an entire garden.

If you grow tomatoes every year, you may have a completely unnoticeable problem - in fact, you probably do have these problems, but they are so picayune that you can't tell.  

The tomatoes are great, everything works smoothly, no complaints.  

Until one day the unnoticeable problems double in numbers, triple, quadruple, then next thing you know you are seeing tomatoes drop in size and leaves are doing weird things.

If, however, the soil had tomatoes one year, broccoli the next, then carrots, maybe Dahlias one year, always a different family of plants, you never have to worry about them.  You can even do it every other year, switch off from tomatoes to something else, then go back to the tomatoes.  Because the pathogens wane, and start from scratch all over.  When you don't switch plants, they don't have to start from scratch.  And you have an epidemic.

Let's suppose you have a fungus.  Moisture on the LEAVES would EMBRACE fungus spores.  Darkness and lack of air circulations are both very bad if you want to control any kind of fungus.  I wish I could see these plants because it is probably a very simple answer.  I don't want to tell you the wrong thing.  But generally speaking, we know fungus needs moisture and darkness and certain temperatures (depending on the fungus) to thrive.

The simplest thing to do, since you are not sure exactly what problem you have, is to take a branch over to your local garden center and show it to someone who gardens there.  I have no doubt they will take one quick look at your tomato stem and give you an on the spot diagnosis.  These problems pop up ALL THE TIME!

Overhead watering gets the leaves wet.  To any fungus spores that are there at the moment, wet leaves spell P A R T Y  T I M E !

Try this last website: aggie-horticulture.tamu.edu/tomatoproblemsolver

from the Texas A&M University.  Maybe this is the key to solving your Tomato problems.  

Fungus is never simple, unfortunately, with or without chemicals.  There are few antidotes to an established Fungus population; treatments consist of keeping the disease contained or sometimes just discarding securely all infected plants.

Please check the aggie link above for your Tomato symptoms.  I am checking my email for reply from these other people about your first problem.

Answer
Well, this is very interesting, Mike.  I hate to do this but you should review the Crop Rotation charts at Yankee Gardener (www.yankeegardener.com/resource/croprotate.html), from which I take the following quote:  "Certain families of plants are subject to the same diseases and should not be planted in the same area more than once every 3 years to prevent the disease organisms from building up in the soil."

Although they may not look it, Tomatoes and Eggplants, along with Corn, Beans and Celery, are One Big Happy Family.  You should NEVER grow them in the same plot in 2 consecutive years.  If you do, THIS happens.

Live and Learn.

Fun, isn't it?

I mean, seriously, next year, having learned all this, when you sit down with your buddies and discuss your vegetable garden, you will have a good story to tell here.  Much more fun than reading it in a book first: "Do not do this."  You would never really, truly understand the implications of those 4 words.  Today, however, they hold incredible pictures of black and yellow leaves, splotched and stunted fruit, this that and the other thing.  This is a great summer, Mike.

I don't think I addressed your statement about ground cover - sorry, I was saying "no" in my head but there's so much to say here and so little time.  The ground cover is not your problem.  Mulching, no problem - in fact, mulching prevents soil pathogens (fungi) from splashing up onto your Eggplant and Tomato family.

Pick vegetables from Column B for next year in that link above.  Or Column C.  Don't grow anything in Column A.  All of Column A has to grow somewhere else - and that means NOT in the "remote area of the garden" where you are now successfully growing eggplant.  And I don't have to tell you why.