By Dianne Weyna, UC Master Gardener of Napa County
There are many flowering trees in Napa's Fuller Park, and this spring would be a good time to see them in bloom. Fuller Park was acquired by the City of Napa in 1905, and in 1919 it was named after the mayor involved in its acquisition, C.H. Jack Fuller. The park is home to over 60 species of trees and is an example of an arboretum or “tree zoo,” having both native and non-native species.
UC Master Gardeners advocate planting native plants because natives are adapted to our conditions, but Fuller Park's tree collection is a resource to appreciate and learn from. If you'd like to learn more about these trees, join the UC Master Gardeners of Napa County on one of their Guided Tree Walks in Fuller Park, held monthly from April through October, on the second Tuesday of each month. Space is limited so please register online. The Napa County Master Gardener website also has information on doing a self-guided tour of Fuller Park's trees. You'll find other tree resources on the website, including Trees to Know in Napa Valley by UC Master Gardeners, available for purchase online or from the Napa County Master Gardener office at 1710 Soscol Avenue, Suite 4, in Napa.
Here's a preview of what you'll see on the walking tour, starting at the corner of Oak Street and Seminary Street. There you'll find the Eastern redbud (Cercis canadensis), a deciduous tree that sports pink flowers in spring and heart-shaped leaves in summer. By autumn, the redbud has seed pods along its branches. It's a great street tree as it doesn't grow too large and the roots are not obtrusive.
I have a redbud tree, and it is full of buzzing bees in the spring. My tree grows straight up, not bent like the one in Fuller Park. The native Western redbud (Cercis occidentalis) is similar to the Eastern redbud. Both can be grown as shrubs or trees and have low water requirements.
The tallest tree native to the eastern U.S., at 191 feet, is a tulip tree (Liriodendron tulipifera) in the Great Smoky Mountains National Park in North Carolina. The one at Fuller Park is much younger and smaller. The tree is in the magnolia family, but its flowers are high in the canopy and not as conspicuous or aromatic as magnolia flowers. The tulip-shaped flowers are light yellow with an orange center. They produce large amounts of nectar in the spring and many seeds in the fall. I have one of these trees in my yard and often pull up seedlings. The leaves turn yellow in the fall and are described as goosefoot shaped.
Near the Laurel Street side of the park is the red horse-chestnut (Aesculus x carnea) a cross between a horse-chestnut (A. hippocastanum) and a red buckeye (A. pavia). The seeds are poisonous but were eaten by Native Americans after boiling them to leach the toxins. Flowers are bright red and fragrant, attractive to bees and hummingbirds. The California buckeye (A. californica), a small deciduous tree that also produces flowers, is common in Napa Valley.
The chitalpa (Chitalpa tashkentensis) was hybridized in 1964 in Tashkent, the capital of Uzbekistan, and brought to the U.S. in 1977. This tree is a cross between two U.S. native flowering trees, the Southern catalpa (Catalpa bignonioides) from the southeastern U.S. and the Southwestern desert willow (Chilopsis linearis). Flowers are light colored and fragrant. It is drought tolerant and can take full sun, but the bark can get sun scald.
The jacaranda (Jacaranda mimosifolia) is native to Argentina and Bolivia and is in the same family as the chitalpa and trumpet vines. It produces aromatic blue-lavender flowers and is common in Southern California and warmer areas worldwide. It is moderately drought tolerant. Although it grows fast in the tropics and is considered invasive in some areas, it is a slower grower in our climate. Jacaranda makes a good shade tree.
Another Eastern U.S. native growing at Fuller Park is the Washington hawthorne (Crataegus phaenopyrum). This tree produces clusters of white booms in the spring that are replaced with red berries in the fall. I personally do not like the smell of the blossoms but bees love it, and many species of birds like the berries. The attractive leaves are triangular and toothed, turning red in the fall. I have a Washington hawthorne as a street tree, where it works well.
On the corner of Oak and Jefferson Streets, notice the Dolgo crabapple (Malus x Dolgo), a variety brought from Siberia in the late 1800s. The soft pink, fragrant buds produce white flowers that are self pollinating. Because the blooms last for weeks, it is considered a universal pollinator, helping to pollinate other apple trees. The fruit is large for a crabapple and can be used for jellies and sauces or eaten fresh.
As mentioned, many of the Fuller Park trees are native to other areas. Napa doesn't provide the ideal environment for their optimal growth. When you plant new trees or shrubs, please consider our native insects and birds. They are in peril and rely on native plants for food and shelter.
Gardening with the Masters: Napa County Master Gardeners and Ole Health are presenting a gardening class on Saturday, March 19, from 10 a.m. to 1 p.m. at Ole Health's Garden at 300 Hartle Court in Napa. Space is limited. Register at https://bit.ly/3sxOpg9.
Got Garden Questions? Contact our Help Desk. The team is working remotely so please submit your questions through our diagnosis form, sending any photos to mastergardeners@countyofnapa.org or leave a detailed message at 707- 253-4143. A Master Gardener will get back to you by phone or email.
For more information visit https://napamg.ucanr.edu or find us on Facebook or Instagram, UC Master Gardeners of Napa County.








In honor of Arbor Day, which was October 21 (we are a little behind, you know why), UC Master Gardener Melody Kendall has these remarks about her favorite trees in Fuller Park.
Arbor Day, which falls on October 21 this year, is a perfect day for a stroll in Fuller Park. This beautiful Napa park is the city's arboretum with over 60 outstanding trees, many marked with signs that provide useful information about each tree. For me, walking the park today is vastly different from my earlier strolls.
When I was growing up here in Napa in the 1950s, the weekend treat was a visit to Fuller Park for an afternoon of fun. Back then, all I was interested in was conquering the spiral slide. Over the years I returned sporadically. In 2014, when I became UC Master Gardener, I finally realized what an amazing place Fuller Park is.
Fuller Park is on the National Register of Historic Places and was originally known as Campbell's Grove. Acquired by the City of Napa in 1905, it was turned into a city park called Oak Street Park. The name was changed to Fuller Park in 1919 to honor C.H. “Jack” Fuller, the Napa mayor involved in the acquisition of the property.
The UC Master Gardeners of Napa County are offering guided tree walks in Fuller Park from June through October. When I joined the tree-walk team, all I knew about the different trees was which ones were evergreens and which were not. That's not much information for conducting a guided tree walk. To learn more, I have since spent many happy hours wandering through the park and familiarizing myself with its remarkable collection of trees.
My favorite tree is the Bunya Bunya, a native of Queensland, Australia. What's not to like about a tree that can reach a height of 140 feet (the recorded high is 147 feet), with a trunk like a dinosaur leg and with cones bigger than a Thanksgiving turkey? Plus, the edible inch-long seeds hidden in those cones have long been a food source for the native peoples of Australia and are still considered a delicacy.
Another exceptional tree is the graceful dawn redwood (Metasequoia glyptostroboides). It is thesole remaining species of its genus. This tree has cinnamon-colored bark and light green, lacy foliage. Believed to be extinct until, in 1941, it was found in a remote region of North China, this tree can grow in standing water. My favorite little factoid about the dawn redwood is that it is a deciduous conifer. While most conifers stay green all winter, this tree's leaves turn a burnt orange and drop. The tree is bare all winter.
Another fascinating tree is the cork oak (Quercus suber). Its knobby, dark-gray bark is a lucrative commodity. Native to the Western Mediterranean and North Africa, most cork oak forests are in Portugal and Spain. The bark is the primary source of cork for wine bottle stoppers, cork flooring, gaskets and the cores of cricket balls.
Once they reach maturity, cork oaks are harvested every nine years. Harvesting the bark doesn't harm the tree; the bark regrows. The year of harvest is marked on the trunk, so each tree is harvested at the right time. Unlike many other oak trees, cork oak is an evergreen and does not drop its leaves. Touching the bark is a very tactile experience.
Among the 60 tree species at Fuller Park, it is hard to find a tree that isn't interesting in some manner. There is a group of Chinese hackberry trees (Celtis sinensis) that are native to Eastern Asia. These trees are members of the cannabis family, but with no THC, which is the psychoactive compound.
The bald cypress (Taxodium distichum) is more often found in the swamps of Florida and in Louisiana bayous with the roots forming knees. Every part of the English yew (Taxus baccata) is poisonous except for the small cup-like structure that holds the berry. The poisonous alkaloid found in this tree contains some chemicals effective in combating lung and prostate cancers and in treating advanced breast cancer.
The English elm (Ulmus procera) was used for water pipes by the Romans because it is not susceptible to rot. The wood of the Northern red oak (Quercus rubra) is so porous that if you blow smoke into one end, it would come out the other end.
The City of Napa and the UC Master Gardeners of Napa County have created a virtual guided tree walk, with posted signs on 40 different trees. Each sign has the common name and Latin name of the tree plus a QR (quick-response) code that you can scan if you have the appropriate app on your smartphone. Scanning the code sends you to the Master Gardeners' web site with information for the tree you scanned. Some brief facts will be displayed with an optional audio link for further information
Celebrate Arbor Day be joining UC Master Gardeners of Napa County on a free guided tree walk on Saturday, October 21, at Fuller Park. Meet at 10 a.m. on the corner of Jefferson and Oak Streets. The City of Napa is an official “Tree City USA,” recognized by the National Arbor Day Foundation. Napa maintains this honor through tree preservation, care and reforestation programs such as the Annual Arbor Day tree planting
Workshop: The UC Master Gardeners of Napa County will hold a workshop on “Toxic and Carnivorous Plants and Mushroom Kits” on Saturday, October 28, from 9:30 a.m. to 11:30 a.m., at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Foxglove. Lily-of-the-valley. Wisteria. These common plants and others are toxic. Who knew? Sundew. Venus flytrap. Pitcher plant. They're carnivorous. While we would not touch a mushroom in the garden, growing edible fungi from kits is easy and neither toxic nor carnivorous. Explore the fascinating properties that plants have to protect them. Online registration (credit card only);
Mail-in registration (check only or drop off cash payment).
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.