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  Mike's Gardening Tips

Yellow Leaves, Black Butts and other Tomato Troubles

Q. Mike! The leaves on my tomatoes started to turn yellow; now some of the plants look close to death. I garden completely organically, and have tried adding more compost, manure tea, and other organic fertilizers. They're getting plenty of water. What should I do?
---Charles; Hainesport, New Jersey

I grow 36 tomato plants in three containers on my deck, each 18 x 33 and six inches deep. I've been doing this for several years and get a pretty good crop. However, the leaves at the bottom are turning yellow. I water about every other day. I have not used any type of fertilizer. Thanks,
---Philip; Exton, PA

Dear Mike: Please help my first garden! My tomatoes get full sun all day, compost and mushroom soil, lots of water morning and night, and are well staked. I even started them from seed! They're big and healthy, but this morning I was about to harvest some yellow ones and noticed they were all rotted at the bottom. What am I doing wrong? Am I over-watering? Are my tomatoes doomed?!
---Laury from Philadelphia (and Rosaline in Doylestown, and...) A. Charles, you might be overfeeding--you can overdo even those wonderful natural fertilizers. Phil, YOU are DEFINITELY starving your poor plants to death! FEED THOSE PUPPIES!!! (And next year, only grow half as many--you're WAY overcrowded!) In addition to over and under feeding, yellow leaves can also be a sign of overwatering, underwatering, 147 different diseases and poor early childhood education. BUT...

...most often these symptoms are the telltale traits of a beast that eventually pounces on all tomato growers: A wilt that builds up in soil where tomatoes are grown year after year. In this area, it's generally Verticillium, but I wouldn't be surprised if its ugly cousin from warmer climes, Fusarium, was enjoying our sultry summers

This year: Remove yellow leaves promptly (wilted ones may recover when the sun goes down). Keep the plants well fed (but not over) and watered (but not over); healthy plants can 'outpace' the disease with their new growth--especially in this weather!

Next year: Grow disease-resistant varieties (they'll have the letters "VF" after their names. Plant in soil where tomatoes have never grown before (or grow in containers on top of the soil, or completely change the soil in infested containers). And use lots of compost (a natural disease-fighter) to try and keep the wilts at bay.

Laury (and Rosaline, and...): If the heinie-end of your tomatoes is black and yucky, you got blossom end rot. The problem is caused by uneven watering--or just plain no watering, or--yes, Lawry: OVERwatering (hint, hint).

This year: Pull off all the fruits showing symptoms; if they're ripe, cut away the diseased part and eat the rest. Mulch the plants well (with anything but wood chips) to keep moisture in the soil, and water them deeply (really let it soak in) twice a week--no more than that! Those roots need to dry out!

Next year: The Amazing Eggshell Trick! Tomatoes that get enough calcium can regulate their water use so well they never get blossom end rot. So save up eggshells all winter long, and put the crushed shells of a dozen eggs in each hole when you plant. Your tomatoes will taste better, too!

Shameless (but relevant) plug: Detailed info on every aspect of successful tomato growing can be found in my new book, You Bet Your Tomatoes! (Rodale, 2002) Available at bookstores, and on the Web! With illustrations by the Daily News' own Signe!

© 2002 Mike McGrath. All Rights Reserved

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