Bermuda almost never gets a disease...unless you water it every day. Deep and infrequent is the mantra. What does that mean? Infrequent means no more often than once a week in the hottest heat of summer. There is the rare exception in Phoenix or Las Vegas where you can water every 5 days. In the cooler months it means once a month. Deep means you put enough water in the ground so the grass will last until the next time you water. Most people start out watering one inch per week and adjust from there. With my soil, grass type, shade situation, heat, humidity, wind, and mowing height, the lawn only needs 3/8 inch of water per week unless we're really having a prolonged drought. Then it goes up to 7/8 inch per week. Everyone's situation is different. You'll have to measure the output of your sprinklers to see how long it takes to get a full inch. Use a tuna or cat food can to measure. Why do it this way? Primarily because weed seeds need continual moisture for germination. Secondarily the deep cycling of irrigation will force the plant to grow deeper, more drought resistant roots. I would back off on the watering and watch the spot to see if it shrinks or grows. If it spreads even with less frequent water, you might need to treat for disease.

Okay back to the original issue. You have brown grass which is likely caused by too much water. It could be a fungal disease that killed the grass. Or it could be drowning by cutting off the air to the roots. In any case that grass is likely dead. Can you post another picture of the brown grass taken at a distance of 3 inches? And can you take it in the shade so we can see the grass with no shadows? Often we can see the fungus if there is any. It will also help identify the grass. I suspect this grass is a type of dwarf tall fescue called Marathon. It is all the rage in SoCal. If so then the grass will not spread by itself to refill the dead grass or the places where you pull out the St Augustine. The only way to get that grass back is to bring in more sod or find Marathon seed. There are three different Marathon grasses. They are Marathon, Marathon II, and III. Each one is dwarfier than the previous one. If you can visit with the people at Home Depot, they might be able to tell you which one they sell - or even if it was Marathon. If you mix Marathon III with Marathon, you'll notice a difference. If you want to be very safe in fertilizing, then use an organic fertilizer. It will be safe no matter what you're doing with the grass. Beyond organic, I cannot advise you. I have not bought chemical fertilizer in over 10 years. Organic fertilizer is hard to find in SoCal. My favorite is alfalfa pellets (rabbit chow). Here is a link to feed stores near you. Call around to get prices and availability before you make the drive. They are scattered around.

Thanks Kasie. I can't see most of the pics but I'm probably experiencing a lot of the same. I'll keep spraying with the fungicide and I guess defoliate but boy do I shudder to think about removing all my leaves. -Heather

Well, I stuck it out in case anyones interested. My two black Krims and 2 of the 4 Big Beef are doing great, maters all over the place, 2 beefs got more beat up by disease but are still hanging on with some fruit but light in the leaf department, and the two OTV brandywines are just starting to flower profusely having reached some 6 feet tall now, hope to see some little maters soon (have exactly one OTV fruit so far). So despite the disease, so far the earthtainers are giving me way way better results than Ive ever had, no wilting etc, lots of fruit. Had lots of problems with Gary Ibsens Gold but now have 3 plants just starting again, they went into the tainers this weekend, hoping they do better this time (seem to be disease magnets, moreso than the rest anyway). Used ortho disease control and a liquid copper fungicide to fight off the speck/spot problem, plus trimming off the worst foliage, biggest problelm is the newest growth, seems to pick up the speck/spot overnight, and often just the very end leaf so Ive been pinching the diseased end leaves off as I see them. And the brandywines seem to excel at attracting fungus or whatever to the underside of the big potato leaves, but all in all this is the least problems Ive ever had, FINALLY! Only took 3 years:).