Jun 1, 2024

There is a beautiful house for sale in my neighborhood, and it was recently featured in the New York Times. Among its abundant selling points is a magnolia tree. It is indeed a lovely tree, and it is in bloom right now. It has glossy blue-green leaves and on the hottest day is cool and refreshing to the eyes. I walk past it every day and admire it.

This tree is the southern Magnolia (Magnolia grandiflora). It is an evergreen magnolia, with large white blooms. I have also seen many deciduous magnolias around town, called saucer Magnolias (Magnolia soulangeana). They are smaller than the southern magnolia, which can overhang a two-story house. Saucer magnolias come in a variety of colors, but the pink ones are the ones I see most often in Napa.

The Sunset Western Garden Book says early spring is the best time to plant trees with root balls that are wrapped in burlap. Container magnolias can be planted anytime. So, if you are interested in one of these trees, which add beauty and value to your landscape, put a reminder in your gardening notebook. Magnolias need sun to flower, but they won't do well in a scorched, windswept area. They are considered excellent landscaping trees, with one caveat—grass won't grow under them, so keep that in mind.

Magnolia roots are sensitive and can be injured. When you plant your tree, it is best to set in some markers to indicate root spread. (You can remove them when the tree is established.)   Dig a hole about one and a half times the size of the root ball and slightly less deep. You want the root cavity to be even with the surrounding ground. Add some compost, and then apply mulch. Keep some space between the mulch and the trunk—don't let the mulch touch the trunk. Depending on your soil, you may need to fertilize occasionally. If your soil is too alkaline, the magnolia leaves will yellow from iron deficiency, so use some iron chelates. Use a controlled release fertilizer for nitrogen deficiency. Don't over fertilize.

The best way to water magnolias is with a drip system that follows the root line. You should water deeply, not with superficial splashing that uses up lots of water but doesn't hydrate properly. Once the tree is established it needs less water.

Magnolias don't need much pruning. I have a friend in Virginia who never prunes her southern magnolia, and it is twenty years old, sixty feet tall, and very healthy. (She also never waters it because Virginia rains in the summer.)  The best time to prune deciduous magnolias is after they bloom. Prune for shape, removing any errant branches. Evergreen magnolias should be pruned in winter before the big spring growth burst. Wear gloves if you do prune your magnolia because the juice from the tree can irritate skin.

Magnolias, biologically speaking, are an ancient tree. According to the Smithsonian Institution, they existed in the Cretaceous period, when dinosaurs roamed the earth--but not bees. Beetles pollinated magnolias then. Because of that, their evolution is unusual. Magnolia flowers have very sturdy carpels, or female parts of the flower, which mimic the stamens, which are the male parts of the flower. The petals of a flower attract pollinators, and the sepal protects the reproductive organs of the plant. Because the petal and the stamen of the magnolia are similar in size and color, the sepal is called a tepal. When the beetle came to the flower, it would roll about in the pollen, covering itself with it. In the evening, the tepal would close over the beetle. In the morning, the tepal would open and release the beetle, which would go off to pollinate another flower. This is how the magnolia achieved cross-pollination, resulting in a stronger plant that has survived for millions of years.

The fruit of the magnolia is shaped rather like a pinecone and is covered with follicles. It contains reddish orange seeds. Birds love the seeds and disperse them widely.

The magnolia is named after a French botanist, Pierre Magnol, a 17th century botanist who worked on plant classification before the Linnean system we use today. According to the Smithsonian Institution, he had an “intuitive understanding” of plant relationships because of their similar characteristics.

I find magnolias fascinating. Maybe it's nostalgia—my childhood was spent in South Carolina. Once a week an old lady would drive through our neighborhood in a Model T, with the back loaded with coffee cans full of flowers that she grew. Her name was Miss Corrie, and my mother would  send us out to buy magnolia buds when they were in season. Mama would put the buds in a dish of water, and we would watch them open. As each petal unfurled, it made a tiny snapping noise. The flower had an intense fragrance with a hint of citrus. When we put the opening buds on the patio table outside, the bumble bees would literally wallow in them. I was only six, but I knew just how they felt.

Library Talk: Join UC Master Gardeners and Napa County Library for “All About Lavender,” on Thursday, June 6, from 7 pm to 8 pm, via Zoom. Have you ever wondered what you can do with that gorgeous lavender growing in your backyard? Learn what lavender needs to thrive, and harvest ideas for how to incorporate it in your own homemade creations. Register to receive the Zoom link.

Workshop: Join UC Master Gardeners of Napa County for a workshop on “Planting for Monarchs and Other Pollinators” on Sunday, June 16, from 2 pm to 4 pm, at Yountville Community Center, 6516 Washington Street, Yountville. Learn about host plants and nectar plants and how to include them in your garden. This workshop is offered in partnership with Yountville Parks and Recreation Department. Register on their website. Click Adult Activities, then UC Master Gardeners, then Planting for Monarchs and Other Pollinators.

Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 am until 1 pm at the University of California Cooperative Extension Office, 1710 Soscol Avenue, Suite 4, Napa. Or send your questions to Include your name, address, phone number and a brief description.