Ask-a-Dave's-Gardener: Greenhouse Cherry Tomatoes -> fuzz -> yellow -> wilt, 1 by LorenAmelang

LorenAmelang wrote:
I started lots of tomatoes in my greenhouse in February. The ones that got planted outdoors are doing great. The dozen that got potted in the greenhouse (16\" classic clay pots, re-used for many successful years) all have a problem. Starting at the lowest leaves and moving up slowly, they get a uniform, non-blotchy coating of white fuzz, as seen in the photo. From the tip of each leaf they gradually turn a uniform yellow, then wilt to a golden tan, dry up, and the entire stem breaks off. Never any spots, nothing visible on the bottoms of the leaves.

Closest photos I\'ve found on the web are of Powdery Mildew, but they aren\'t a perfect fit. I tried the baking soda spray, with a bit of neem oil and sticker, twice, and didn\'t notice any difference - the problem crept up through the sprayed leaves at the same rate. I\'ve been removing affected leaves before they wilt, on the theory of reducing spores, but I\'m not sure that helps either. Several sites said reduce water and don\'t fertilize, so I\'ve kept them pretty dry and hungry - but not limp at all. Supposedly warmer, drier weather should help, but the few hot days last week made no obvious difference.

I\'m beginning to wonder if it could be the soil. I changed brands completely this year, much less vermiculite and peat, more fine wood fibers, some really coarse wood fibers mixed in at the bottom, and no coir except in a 1/2\" mulch layer on top. A couple of handfulls of organic dry fertilizer per pot. I notice the other indoor plants that got the same soil are also pretty pale. I tried a hit of liquid \"Grow Big\" fertilizer on one plant two days ago, and I\'m convinced it is deeper green, but the problem is progressing through it just the same.

Does anyone recognize what I\'m missing here?