The best time to plant Encore Azaleas is fall, from September through November, with early spring (March through April) as your second-best window. Fall planting gives roots months of mild weather to spread out before summer heat arrives. Spring works too, but you'll need to water more during that first hot season.
I've planted Encore azaleas in both seasons and the results speak for themselves. My fall-planted group went into the ground in mid-October three years ago. By the following spring, those plants were twice the size of the ones I had planted that same March. Planting azaleas in fall gave them a huge head start because the roots kept growing through the mild winter months while the tops stayed dormant. The spring group spent their first summer just trying to survive the heat instead of putting down strong roots.
Root science explains why fall wins. When soil temps drop to 50 to 65°F (10 to 18°C), azalea roots grow fast with no competition from leaves and flowers. The plant puts all its energy underground. In my experience, fall-planted azaleas get a 4 to 6 month head start on root growth. More roots mean better water uptake and stronger growth when spring arrives.
Spring azalea planting still works well if you missed the fall window. March through April gives you cooler temperatures and spring rains that help new plants settle in. The catch is that summer follows close behind, and a newly planted azalea with a small root system struggles in 90°F (32°C) heat. You'll need to water at least three times per week through that first summer to keep a spring-planted Encore alive and growing.
MSU Extension notes that container azaleas can go in the ground any time of year. Their roots are already set in the pot. But just because you can plant in July doesn't mean you should. I tested a summer planting once and lost one of three plants to heat stress even with daily watering. Winter planting in frozen ground is just as risky. Stick with fall or spring for your best odds.
When you think about when to plant azaleas, match the timing to your local climate. Gardeners in zones 8 and 9 can plant as late as November since their winters stay mild. Zones 6 and 7 gardeners should aim for September or early October to give roots enough time before the first hard freeze. If you plant in spring, get your azaleas in the ground before temps hit 80°F (27°C) on a regular basis.
No matter which season you choose, water your new Encore azaleas once every two to three days for the first month. Then drop back to once or twice a week for the rest of the first year. Consistent moisture during that time matters more than the exact planting date. Skip summer and winter extremes. Plant in fall or spring and you'll give your azaleas the best possible start.
Read the full article: Best Encore Azaleas for Your Garden
