Gardens of the Cross Timbers: Plant zoos

Becky Emerson Carlberg
Contributing writer

The native spring flowers keep coming. The dewberries (Rubus species), close relatives of blackberries, form trailing vines close to the ground, not upright canes. Dewberries bloom before blackberries and are now producing five petaled white flowers. Soon, sweet little squishy purple raspberry-like fruits will be ripe and ready.

The black locust trees (Robinia pseudoacacia) are blooming. If planted near crops or trees, the nitrogen-fixing legume enhances their growth. Honeybees and bumblebees love the flowers. Another example of an American plant taken overseas. Hungarians imported black locust seeds in the 1700s. Through selective breeding, strong black locust stock was developed. Not only are Hungarian forests almost 20% black locust, the tree has become important in their commercial honey business.

Can’t miss the Indian Paintbrush in brilliant bloom along the roadsides and in fields. Castilleja indivisa is much like the Poinsettia. The showy color comes from bracts below the small greenish flowers. Not all Indian paintbrushes are reddish-orange. I saw a greenish yellow stand along the road, no orange at all. Light yellow as well as pure white paintbrushes also occur.

Yellow Indian Paintbrush

Indian Paintbrushes have bust or boom cycles. Some years are fair, but others are extraordinary. Whenever their roots come in contact with native grasses or other plants, they often penetrate into those root systems for a little more sustenance. Doesn’t seem to bother the grasses, but the paintbrush is considered hemiparasitic. Butterflies, bees and hummingbirds find Indian Paintbrush a good food and nectar source.

Fleabane Daisies (Erigeron species) now raise their floral heads to the sun. The small complex daisy flowers with bright yellow centers may number over 35 on a single plant. Apparently, fleabane daisies taste great to deer and rabbits, but are also host to leafcutter, mason, sweat, bumble, honey and other bees as well as bee flies, wasps and gossamer-winged butterflies. Fleabane? The story goes these daisies either killed or repelled fleas. Attractive early spring flowers for gardens.

The concept of the garden has roots in the Chinese Zhou dynasty over 2,000 years ago and has gradually evolved through place and time. Many large Botanical Gardens now have a strong European flavor.

If your garden looks a bit anemic, why not visit a Botanic Garden. Over 2,500 major botanic gardens in the world house 6 million types of plants, amounting to one quarter of all vascular plants (plants with defined water and nutrient conducting tissues). The gardens are well-maintained and multi-functional with emphasis on research, teaching and education. These gardens will become ever more important as more and more plant species disappear through human activity and changing climates. The target of the Global Strategy for Plant Conservation is to collect, protect and propagate 70% of all threatened plant species.

Botanic Gardens showcase a variety of plants and offer sites for scientific investigation in cultivation, propagation and pollination as well as observation of plant and animal interactions. Prevention of hybridization is a top priority to ensure preservation of the genetic constituency of endangered plants. Monitoring native pollinator involvement with foreign plants helps understand how the non-natives may become naturalized. Botanic Gardens aim to conserve as many plant species as possible with help from the public, citizen science volunteers and academia. Think of Botanic Gardens as plant zoos.

Cherry trees at the Jefferson Memorial

Washington D.C. is the home of the United States Botanic Garden. This year I watched the cherry trees in the Tidal Basin of Washington D.C. via the live BloomCam. Trees were beautiful, but pedestrians and vehicle parking were limited. Temperatures above normal speeded up the bloom cycle and moved peak bloom of the 1,400 Yoshino Cherry trees (Prunus x yedoenis) to March 28. The 400 Kwanzan Cherry trees (Prunus serrulata ‘Kwanzan’) usually flower a few weeks later. Eleven species of cherry trees live in West Potomac Park. Cherry blossoms are notoriously weather sensitive. One-hundred-year records indicate the cherries are blooming earlier than ever. Temperatures in Washington D.C. have risen 2 degrees F during that time.

Kyoto Japan has been keeping track of weather patterns since 812. A pattern has emerged the last 150 years. Their cherry trees are also blooming ahead of schedule. Peak bloom this year was March 26, the earliest in 1,200 years.

The ‘Endow a Cherry Tree Campaign’ is an annual fund-raiser. May 20 is the last day. Each year the Trust for the National Mall seeks donations to help pay for the upkeep by the National Park Service of the 3,800 cherry trees on the National Mall. Some of the trees are over 100 years old. Young descendants are planted each year to continue the cherry tree heritage. These beautiful trees belong to all Americans. They are our trees as are the monuments and memorials on the National Mall (most were not funded by the government but through private donations).

Two hundred cherry trees grow in the 52-acre Brooklyn Botanic Garden, including one cherry tree 91 years old. The Chicago Botanic Garden covers 385 acres with millions of trees and plants. The 66-acre Royal Botanic Garden in Sydney, Australia has over 30,000 plants, one of the world’s largest collections. Might take more than a morning to check these gardens out.

Of course, there’s the 300-acre Kew Gardens in the United Kingdom (fantastic place) or the lush 55-acre Butchart Gardens with 2,500 varieties and 30 arches of roses in British Columbia, Canada (recommended by my podiatrist). The 79-acre Missouri Botanical Garden in St. Louis (Bonsais) is our country’s oldest Botanic Garden still in operation.

We have outstanding gardens right here in Oklahoma. lists several, but here are a few: Will Rogers Gardens in OKC, the Myriad Botanical Gardens and Crystal Bridge Tropical Conservatory in OKC, Honor Heights Park in Muskogee, Philbrook Gardens in Tulsa, Tulsa Botanic Garden, Bivin Garden in Shidler (rock gardens) or Lendonwood Gardens outside of Grove.

Check to make sure the gardens are open. Fill up your wheels, pack snacks, cell phone, camera, good shoes. Spring is an excellent time for a Plant Zoo Road Trip.

Becky Emerson Carlberg

Becky Emerson Carlberg, graduate of Oklahoma State (Plant Pathology) is a teacher, artist, writer as well as certified Oklahoma Master Gardener and Master Naturalist. Contact her at