I've always grown tomatoes in 5 gallon containers. my opinion is it could be 1 of a few things. 1) pot bound when the soil is dry, grab the stem and lift the root-ball to inspect the roots, it the soil ball comes up very easily and you can see roots covering the surface, it's time for a transplant. if the plant doesn't come out very easy don't force it and cause more damage. just check the holes in the bottom of the pot, if they are showing roots it's time to transplant. 2) a salt buildup how often do you water between feedings. if salt is built up in the plant the lower leaves will die until the entire plant is dead. the salt comes from fertilizer that is not rinsed from the soil with pure water and builds up in the roots restricting nutrient uptake by the plant. to remedy this you would water with nothing but water for 2 weeks every time the soil goes dry. tis will flush out any built up salt in the soil. check your water as well becuz city water is sometimes too acidic for plants and will effect growth dramatically. 3) Watering Time watering in the morning before 11 AM or after 5 PM helps any plant keep cool during the hottest days. the hotter parts of the day are between 11 AM and 5PM so watering during these times of the day are best avoided to prevent steaming the roots. IMO i would say it is most likely the root bound issue.

Treelover - THANK YOU!!! I had begun to think nobody was going to notice my little cry for help! Your cosmos situation doesn't look quite the same as mine, but I think you have hit on the cause of my problem: you mention the sprinkler, and just yesterday I was looking closely at the plants when it came to me that all the plants (dahlias included) that are having a problem are closer to the sprinkler nozzle. And in the dahlias' case, it's the side of the plant that faces the sprinkler action that has gone bad. I think you are also right that I have given them too much water. I should tell you that I am a complete novice in regard to ALL the plants I have in containers here. I was an apartment dweller all my life until year before last, when I retired and moved in with my widowed sister, who doesn't like to garden and is happy to give me free rein. I find I just love it, but I sure have made a lot of mistakes! Although I'm beginning to realize that in gardening, you can do everything the way you are supposed to and STILL have things go wrong! It's all been very good for my attitude: I find I have gotten much more philosophical toward failure/success. Anyway, it's all fun! Thanks again - Laura

Usually when the yellowing begins at the oldest leaves first and works its way up progressively through the older leaves ... and the yellowing is uniform yellowing with no black spots or ringed blotches on the leaves ... that is a sure sign of the plant robbing nitrogen from the older leaves and transferring it to the new growth ... meaning your plants are asking for a nitrogen boost. However, I don't see the "yellowing" ... all I see in your pictures is some off-color, dull khaki colored leaves like in that third picture, then it seems the coloration goes to dry, dead, dark tan or light brown. Also, look at that first picture and the last picture where the discoloration seems to have skipped past some of the older leaves and is well progressed on a some of the foliage in mid-plant. That doesn't seem indicative of typical nitrogen deficiency which would seem to be the first deficiency that would appear if indeed you are flushing or leaching out nutrients by over-watering as N is more unstable and "leachable" than P or K ... and you say you're fertilizing regularly with Miracle Grow. So, I don't really suspect it's lack of application. I'm thinking possibly disease of some sort. I'm not familiar with Miracle Grow plant growing mixes, but I did have trouble this summer with a knock-off brand of the same type stuff from Scotts (which I think is the same company now) where it was just to moisture rententive for the tomato plants I happened to use it for. I thought I had lucked into a good deal when I got a couple of busted bags for half price ... but the plants in that mix withered up similarly to yours, but not exactly the same color or pattern of disorder. But the mix always seemed saturated. My other potted tomatoes never had a problem all summer even though I watered them nearly daily and at the risk of overwatering ... but they were in a very porous homemade mix and never showed the least sign of what we're talking about here. So, I'm really no help with regard to the possibility of over watering. Personally, since your plants are showing that funky off-color on the leaves AND some of the stem tissue ... and since there seems to be some leaf distortion going on there too ... like a little roll while there's still some greenish color left ... you may want to take some examples of leaves to your county extension horticulturalist. If you do, take some healthy leaves, some that are just starting to show the disorder, and other foliage AND some of those discolored stems in various stages of dying and death so she or he has enough evidence to make a determination whether you're dealing with a fungal or bacterialogical agent or some other thing we all may be missing here.

Well, unless you do have something like spider mites (have you checked?), I'd say you're watering way too often... not all plants/trees like to be wet all the time, tho' the answer now would not be to let all the soil dry completely, but maybe halfway this time, then give it some, but not soak it. Watering from on top is best too, not sinking it in a tub. And you need to give it as much bright light for as many hrs/day as possible, even if it means (short term) changing windows... but of course never near any dry heat. Don't be concerned about fertilizer for now... that can come later. Where do you live in terms of climate? If you're in the south, your tree could even go outside if temps stay above 50 F. overnite. Give it time to recover - weeks - and see how things go. Also, you could always Google Grewia occid. care and see what comes up.