Encores to the Extreme: Tips for success in hotter areas of the West

Don't think Encores can grow in the desert? Mary-Kate Mackey speaks to one landscape professional whose shrubs are thriving.

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By Mary-Kate Mackey

“I had my doubts about growing Encore® Azaleas,” said Joan Cartwright. And well she might. Joan gardens in Vacaville, Calif., on the desert’s edge of California’s Central Valley. Days in August can top 100 degrees F and the humidity hovers between 22 and 35 percent. And yet, she said, “It’s astounding how well they do. They’re as easy to grow as any shrub I’ve tried.”

I met Joan in the exhibit hall of the FarWest trade show in Portland, Ore. Joan and I began a conversation about Encores after I explained I’d been writing about them. Joan smiled, and like a doting parent, pulled out her phone to show me her Encore photographs. Her plants displayed lush foliage and strong blooms. “They do great. And look, they’re coming on again for fall, ” she said.

Encore Azalea collage
Autumn Amethyst and Autumn Sundance planted in the desert. Photos courtesy of Courtesy Joan Cartwright

I had to find out how Joan did it under those less-than-optimal circumstances. She’s been in the nursery business for more than 30 years, so she knows what she’s talking about. Here’s what she shared:

Location

Her Encore® Azaleas are planted on the outside edge of a low bricked area that receives full sun from 10 a.m. to 3 p.m.

Soil

Desert earth tends to be alkaline (high pH), and Encores are happier in a more acidic environment, so Joan amends with a generous amount of peat moss, mixing it in a 50/50 ratio with the soil. The added organic material helps lower the pH and also holds more water.

Water

“The key is to water evenly,” Joan said. She installed a drip-spray irrigation system with the heads spaced 5-feet apart. In hottest weather, a timer is set for 12 minutes, 3- to 4-times a week. When the weather cools down, she reduces the minutes. In addition, once a week Joan hand-waters with a hose-end sprayer, soaking each plant for approximately a minute.

Mulch

She top-dresses around the plants with a 3-inch layer of miniature bark to keep the roots cool and hydrated.

Food

When she planted her Encores, she added a time-release fertilizer for flowers into the hole. Now in spring and fall, Joan’s Encores receive a balanced 16-16-16 fertilizer, which she spreads evenly on the ground to prevent burning and waters in well. “You could also use a granulated fertilizer for acid-loving plants,” she said.

Pests

The only thing that seems to bother her Encores are snails, so she said she baits for them after the Encores bloom.

Bloom times

“In my area, Encore® Azaleas bloom heavily in the spring, and a medium amount with a great look, in the fall,” Joan said. After the spring bloom, she said she shears for shape and to encourage vigor.

Size

In these extreme conditions, Joan said she has had the most success starting with bigger, more established plants (3-gallon containers work best). “Smaller sizes have to work harder to keep up. Although they all come along eventually,” she said. “If I had more land, I’d plant more.”