the show

Garden Conservancy Tour

air date: October 20, 2012

Preview The Garden Conservancy Open Days Austin 2012 tour with Charlotte Warren and Laura Bohls. Get a closer look at landscape architect Curt Arnette’s contemporary design that interfaces the land, family engagement, and wildlife. Daphne explains why spring trees bloomed this fall. Her pick of the week is Mexican olive. Trisha shows how to combine winter vegetables and edible flowers, even in containers.

Question of the Week

Why are my redbud trees blooming in fall?

The reason is the weather. Thanks to D. Kirkland for her great question and picture! Although it wasn’t as bad in 2012 as the landmark year before, the drought continues, and we still have a pretty large deficit of rainfall. So the lack of predictable soil moisture continues to be a stressful issue for plants. And when plants are stressed, they behave out of character. You may notice a decline in plant health during stressful conditions, which would be logical. It makes perfect sense that a tree that isn’t getting enough water to sustain itself will drop its leaves and have declining health.

But often something really interesting happens if the environment improves significantly: the plant rebounds and works hard to take advantage of the situation before the opportunity passes. In the redbud’s case this year, after a second hot, dry summer, they took advantage of early fall rains to sneak in a few flowers. Temperate zone plants are particularly sensitive to the seasons, especially the length of daylight and the temperatures. Without this sensitivity, plants would not “know” when to drop their leaves for winter or when to flower and produce the next generation. But when the weather is wonky, which it has been around here for a while, plants do behave strangely.

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Plant of the Week

Mexican Olive

Mexican Olive

Cordia boissieri

Also known as Texas Olive or Anacahuita, this plant is not related to the true olive, but it does produce a similar-looking fruit. And even though the fruit of the Mexican olive is not palatable, its foliage and fragrant flowers make this a show-off shrub for us! Although it has a shrubby habit, you can prune it as a tree. Or, develop its shrubby habit as a natural screen. In normally frost-free regions such as south Texas, it will remain evergreen and can get up to 20' feet tall and almost as wide. But in areas that typically see at least a few periods of freezing temperatures, Mexican olive will be smaller and deciduous or evergreen, depending on the weather. Mexican olive loves the heat and the full, bright sun. It does require good drainage. It's very drought tough, so it doesn't need much water after it's established. Large white fragrant flowers cover it from late spring to frost, attracting many pollinators and hummingbirds. It produces white fruit that resemble olives. While they are edible, the olives are not enjoyable for us, but wildlife will appreciate them. It can be rather messy when the booms and fruit drop off, so it's not the best choice for a driveway or pool.