Answer: This tree Laburnum x watereri is rated hardy into zone 5, however it needs to be planted in a sheltered location out of the wind. It also does best with some shade in the middle of the day since your summers are so hot. In my experience, this is not an easy plant to grow -- it would do better in a milder climate such as the Pacific Northwest. To give it the best chance, provide soil that is rich in organic matter with a neutral to slightly higher pH and stays evenly moist yet well drained meaning not soggy wet.
In relatively difficult conditions it is not a strong grower and is not expected to be a long lived tree. The fact that garden centers are not stocking it is a good indication that it is not expected to do very well in your area. You might contact garden centers in nearby large cities and see if they ever carry it, the zip code locator might be useful in doing that.
If you can't find it locally, laburnum is currently listed in several reputable nursery mail order catalogs such as Greer Gardens, Wayside Gardens, Forest Farm and Fairweather Gardens. If you go to
and type in Laburnum as your key word, you will find these listed.
Good luck with your golden chain tree!
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