Tomato Problems?

Advice from the Help Desk of the
UC Master Gardener Program of Contra Costa County

Subject: Summer Tomato Problems

Client: Came to our Help Desk office with multiple problems with his tomatoes and maybe on his samples of rosemary and rhododendron

Help Desk Response: Thank you for coming to the UC Master Gardener Program Help Desk with your multiple tomato and plant problems. They appear to be all typical of growing tomatoes in the home garden in the County – early blight, “catfacing”, and blossom end rot. We also made an assessment of the health of your rosemary and rhodedendrons.

First, we discussed the early blight problem on your tomato plants. In particular, we discussed that spores of the early blight fungus in your case were spread by splashing water, so it is important to keep the leaves as dry as possible. We also discussed using mulch to reduce the spread of spores from old infected leaf material in the soil, and using crop rotation techniques. Here is a link to additional information and photographs http://ipm.ucanr.edu/PMG/GARDEN/VEGES/DISEASES/tomearlyblight.html. 

catfacing green tomatos

We further identified a disfigurement on the bottom of the tomato fruit as a physiological problem called catfacing. It occurs when weather is too cold during flowering. There is not any way to prevent this but the problem will not spread and the fruits are safe to eat.  A link to that information is here http://ipm.ucanr.edu/PMG/GARDEN/VEGES/ENVIRON/catfacing.html 

We also discussed the physiological problem called blossom end rot on your tomato. It occurs when the soil is allowed to dry too much, causing a calcium deficiency in the tomato plants. The way to reduce this condition is to make sure the soil moisture stays even and does not dry out too much between waterings. Adding calcium to the soil is not necessary. More information and photos can be found here http://ipm.ucanr.edu/PMG/GARDEN/VEGES/ENVIRON/blossomendrot.html

Finally, I looked at the specimens of rosemary and rhododendron leaves you brought in, and confirmed that there were no pests or diseases there. However, both plants appear to be water stressed and should perk up with additional irrigation.

I hope that this information is helpful. Please do not hesitate to ask for advice again. We are here to help.

Help Desk of the UC Master Gardener Program of Contra Costa County (JL)
(all pictures from UCANR links cited above)

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Note: The  UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions.  Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA  94523. We can also be reached via telephone:  (925) 646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog  (//ucanr.edu/blogs/CCMGBlog/).