Exploring the Magnolia Hybrids of David G. Leach

By Connor Ryan, HF&G Rhododendron Collections Manager

As the Rhododendron Collections Manager at Holden Forests & Gardens, I have the exciting job of carrying on the legacy of the late David G. Leach. Most of this revolves around the numerous Rhododendron hybrids David created and named, many of which are housed at Holden’s David G. Leach Research Station, but another significant part of the Leach story are the 9 magnolias he developed and named. Holden Forests & Gardens social media has been providing periodic updates of the various magnolias we have on our grounds, but I wanted to provide a little detail on how these hybrids are created.

Magnolias are pollinated by beetles, believe it or not, and evolved before bees ever existed. Their flowers open in two phases, first a female phase and then a male phase. This ordered flowering is termed protogynous – “proto-” meaning first (like in “prototype”) and “-gynous” meaning the female parts of the flower. It is during the female phase that a magnolia flower first opens and pollen from one magnolia can be placed on the curved stigmas (Photo 1). Soon after the female phase, the flower will close and the stigmas will flatten. A day or so later, the magnolia flower will reopen during the male phase (Photo 2). In the male phase, the stamens (male reproductive parts) release pollen from their anthers which will be spread by pollinators or can be collected and stored for future breeding. Over the summer, successfully pollinated magnolias flowers will develop into the long, alien, cone-like fruits many of us are familiar with, called an aggregate of follicles (if you want to impress your friends).

Plant breeders make crosses between two plants to reach certain goals. For David Leach’s yellow-flowered magnolias, he wanted smaller trees that develop yellow flowers after the last chance of frost. Sometimes a breeder’s plans work out, and they get the perfect magnolia they were aiming for. Leach’s ‘Golden Gift’ is a good example. Most of the time, plans do not work out. That is the life of a plant breeder. But sometimes, like for David Leach’s ‘Coral Lake’, a little serendipity plays a role and a Magnolia unlike anything planned shows up. ‘Coral Lake’ is reportedly a hybrid between two yellow magnolias, but clearly some unplanned pollen made its way onto a flower during its female phase. Its coral-, almost orange-colored, late-blooming flowers is a trait rarely seen in magnolia hybrids.

Some of the most successful ornamental plants have come from amateurs breeding in their own back yards. If you have a magnolia or two in your yard, give it a shot! You never know what you’re going to get.

Photo 1. Single and ready to mingle! A Magnolia in its female phase with curled stigmas ready to receive pollen. The stamens, from which pollen is released, are tight against the central column and will open after the female phase, a day or so later.
Photo 2. A magnolia flower well into the male phase. The stigmas have flattened against the central column, and the anthers have opened, releasing pollen to the world.
Photo 3. Magnolia ‘Golden Gift’, probably David Leach’s best yellow-flowered magnolia. This particular tree is part of a trio of ‘Golden Gift’ planted in Holden Arboretum’s Rhododendron Discovery Garden.
Photo 4. David Leach’s ‘Coral Lake’ magnolia at Holden’s David G. Leach Research Station. ‘Coral Lake’ is reportedly a hybrid between two yellow magnolias, but clearly something went awry. And thank goodness it did. In peak bloom now!

 

Connor Ryan is the Rhododendron Collections Manager at Holden Forests & Gardens . His primary responsibilities are overseeing the management of our David G. Leach Research Station and curating our Rhododendron collection. He has broad interests in woody plant ex-situ conservation, woody ornamental plant breeding, and plant propagation. Before coming to Holden, Connor earned a bachelor’s degree in Plant Science from Auburn University and a master’s degree in Plant Breeding, Genetics, and Genomics from the University of Georgia.