Lobularia White Stream, a hybrid alyssum, has been selected as one of the 2015 Texas Superstar plants.

“White Stream is a new type of alyssum that will survive the heat of Texas summers,” said Dr. Brent Pemberton, Texas A&M AgriLife Research ornamental horticulturist and head of the Texas Superstar board, Overton.

Alyssum has traditionally been a cool-season plant, Pemberton said.

“It’s been happy in summers up north where it’s cool. Here, we grow it in the fall, as a winter plant and it will usually survive the winter in a protected location,” he said. “But White Stream is just a whole new thing. In fact, it won’t tolerate freezing temperatures at all. It gives gardeners in Texas the opportunity to have that kind of plant in the summer landscape.”

Lobularia White Stream was developed by Danziger, an international floriculture company. White Stream is a spreading annual that makes a mat; it’s used as ground cover in landscapes and produces fragrant flowers all summer, Pemberton said. It can also be grown in large pots as a patio plant.

All Texas Superstar plants undergo extensive tests throughout the state by AgriLife Research and Texas A&M AgriLife Extension Service horticulturists, Pemberton said. He’s personally tested White Stream at the East Texas Horticultural Field Day trials at the Texas A&M AgriLife Research and Extension Center at Overton for the last three years, along with other alyssum varieties.

To be designated a Texas Superstar, a plant must not just be beautiful but also perform well for consumers and growers throughout Texas. Superstars must also be easy to propagate, which should ensure the plants are not only widely available throughout Texas but reasonably priced, as well, he said.

Pemberton noted that Danziger has other hybrid alyssums in the series: Lavender Stream, Silver Stream, Summer Stream, White Stream, Purple Stream and Bicolor Lavender. White Stream was chosen among the others because it proved to be the most heat tolerant.

All the hybrid alyssums are full-sun plants, he said. Though the cool-season alyssums are grown from seed, the heat-tolerant series is vegetatively propagated, and no seed is available at wholesalers or retailers, only rooted cuttings.

“You should be able to buy it in six packs or 4-inch pots – it’s probably going to be more available in 4-inch or larger pots,” Pemberton said.

In the landscape, plants should be planted in about 1-foot spacings after the last freeze, he said. Fertility needs are the same as any other bedding plant. With good growing conditions, Lobularia White Stream should spread to fill in the spacing and create a good mat in about three to four weeks. Water use is moderate. They have limited tolerance to drought, but tolerate reflected heat well.