Houston Chronicle Sunday

Tomato-planting time is very specific

- By Bob Randall

In 1992 I coauthored a book on growing tomatoes because year after year, decade after decade, I routinely got lots of great organic tomatoes in spring and fall. This spring, however, was the worst spring tomato harvest in 35 years. Our ever-hotter Gulf combined with a “moderate” El Niño lead to the wettest spring in Houston history and the wettest single month in Texas history.

Because of El Niño and the National Weather Service three-month prediction­s last fall, we planted more tomatoes this year than usual, so lately we have had enough to eat. But the endless cloudy days, cooler-than-normal temperatur­es and soggy soils reduced yields so much that there are none for canning, drying or for making salsa. Urban Harvest Farmers’ Market Manager Tyler Horn echoes this sentiment. It looks like, therefore, that the 2015 spring is a tomato disaster.

For gardeners in urban Houston south of I-10, or in the area bounded by southern Houston and a line between Pearland and Sugar Land, or areas within 10 miles of the Bay or Gulf, fall tomatoes are a very good idea. In other places, most years they will need at least lightweigh­t greenhousi­ng to produce well.

Probably the most important issue for fall tomato growers is to understand that tomato flowers have sterile pollen outside of a relatively tight range — roughly the temperatur­es when people enjoy being outside day and night without either protection from heat or cold. Tomato flowers become fruit only when day temperatur­es are in the 70-85 degree range and night temperatur­es are in the 55-70 degree range.

So if you are good at predicting when these temperatur­es will occur where you garden, and you plant seeds and transplant­s far enough ahead to have them flower at the right time, you will get little green tomatoes. And they will produce ripe ones or ripe-enough-to-pick ones a month or so after that if the plants have the right temperatur­es before a frost occurs.

You can find daily highs and lows for many area airports at “monthly data” reports linked at www.srh. noaa.gov/hgx/?n=climate. Generally, no part of our area gets daily high temperatur­es below 85 degrees until late September, and that isn’t consistent until mid-October at the earliest.

So there is no reason to have flowers before late September. In the last few years, Galveston, League City, Sugar Land, Pearland, Hobby and Houston south of I-10 have mostly avoided November freezes, so fruits that form in September and October have enough time to ripen. But Lake Jackson, Interconti­nental, Tomball, College Station and Huntsville have all had light November freezes most years, so without a plastic greenhouse, they won’t produce.

To get good results, do a few more things. First, choose cherry tomato types like Sun Gold or Sweet 100 or Sweet One Million. They have many more flowers than do larger tomatoes, so are more likely to be blooming when the temperatur­es are right.

Second, either plant seeds in lightly shaded pots just after July Fourth, or buy early August transplant­s. In either case, transplant them to 24-ounce or larger pots in early August and plant the big pots in the garden about Labor Day. Continue the light shading over the plants in the garden with shade cloth until the tomatoes are growing well. We did this last fall and enjoyed fresh tomatoes until April.

For further informatio­n on growing tomatoes see urbanharve­st.org/ vegetables or take my Fall Organic Vegetables class at Urban Harvest on Saturday, July 25.

And, please take a moment to appreciate Raymona Bomar, who passed away this month. Her tireless, creative and competent spirit of service helped in a major way to build Urban Harvest.

Bob Randall Ph.D. is the retired co-founder of Urban Harvest and is author of Year Round Vegetables, Fruits and Flowers for Metro-Houston. Contact him at http://yearroundg­ardening. me and BobInTheGa­rden@ urbanharve­st.org. Urban Harvest produces this column. Learn about gardening classes, community and school gardens, farmers’ markets, fruit tree sales and more at urbanharve­st.org.

 ??  ?? Heavily mulched late-September tomatoes thrive.
Heavily mulched late-September tomatoes thrive.
 ?? Photo by Urban Harvest ?? The 2003 Urban Harvest Board adopted a successful plan. The late Raymona Bomar (first row, far right in red), helped make it happen.
Photo by Urban Harvest The 2003 Urban Harvest Board adopted a successful plan. The late Raymona Bomar (first row, far right in red), helped make it happen.

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