the show

Structure and Softness

air date: June 16, 2012

Jon Hutson from Tillery Street Plant Company combines structural and soft plants for beautiful drought-tough designs. On tour, see how east Austin gardeners renovated their old yard with tailored structure mixed with abundant plants. Daphne explains why blossom end rot ruins early tomatoes. Pick of the week is structural and soft Manfreda. Eric Pedley from East Austin Succulents demonstrates how to divide succulent plants.

Question of the Week

What is this black rot on the bottom of my tomatoes?

Thanks to Russell Bauer for this great question! We’ve heard from many other gardeners about their tomatoes that Since we’ve heard from many gardeners, have a mushy black or brown rot on the bottom. This is blossom end rot. Thanks to Russell Bauer for sending this picture.

Blossom end rot is a common disorder in tomatoes, but may also be found in peppers and eggplant. It’s caused by a calcium deficiency in the fruit, but adding calcium to the soil won’t solve the problem. As plant cells are developing, they require a lot of calcium. And tomato fruit develops quite rapidly, sometimes depleting the plant’s available calcium supply. There are many reasons why your tomato fruit may develop faster than it can replenish its calcium, but usually the reason is irregular watering. Soil that is very wet, when you irrigate, then very dry, between waterings, leads to irregular water-uptake and fruit that develops in fits and starts. Usually blossom-end rot is only a problem for the first harvest of the season, then plant growth kind of evens out, and water-use by the plant evens out a bit too. When growth and water uptake occur at a steady rate, the fruit develops in a more even manner as well and cells in the fruit receive enough calcium to develop properly. Certain cultivars and varieties of tomatoes are more prone to blossom-end rot, so you may want to choose different varieties next year, if you have a large problem with a particular variety this year. If you continue to have issues, you might try using sulfur to acidify the soil a bit and using a fertilizer with nitrogen in the nitrate form, not the ammoniacal form. Calcium sprays to the plant don’t remedy the situation much, since not much of the calcium applied to the leaves gets into the fruit, where it’s needed.

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Plant of the Week




There are many different species in the genus Manfreda. You may also find hybrid Agave/Manfreda crosses, called Mangaves. All are native to the southern US, Mexico and Central America and are great succulents for your garden. One species of Manfreda is known as Texas tuberose. As with most succulents, Manfredas require loose, airy soil with excellent drainage. Gardener Brent Henry has clay soil so he mixes in decomposed granite to improve drainage. His Manfredas get partial sun with most of the sun in the afternoon, but shaded by a bur oak. He gives them practically no water, and all have survived hard freezes and tough droughts just fine. They bloom reliably every spring with a 4 foot spike. Manfredas have a low-growing, rosette habit and don't take up much space in the garden. With their long, sometimes curly leaves, they also look great in containers, especially when the container color plays off the spots on the leaves.