The Future of Hybridizing

The future of hybridizing has already begun; we soon will see the transformation of Nature’s ancient methods, and the rapid introduction of amazing new cultivars.

The basic method for creating new varieties of ornamental and edible plants has been practiced by bees and other pollinators for a very, very long time. This approach, called crossbreeding, involves sexual propagation: fertilizing one plant with the pollen of another plant produces seeds that carry the traits of the two plants. When the seeds germinate, the next generation of plants shows combinations of the traits of their two parents.

Plant hybridization has advanced greatly since 1900, when modern genetics began on the basis of Gregor Mendel’s work, but still follows the natural process. Rather than combining plants randomly, like bees, human hybridizers try to combine the traits of two plants to produce hybrid plants that are better than either parent. With ornamental plants, for example, a hybrid’s blossoms might be larger, more attractively colored, more numerous, etc.

This process requires time for seeds to germinate, develop into new plants and reproduce to produce a marketable number of hybrids. Often the majority—or all— of the seedlings do not equal the hybridizer’s vision, and are discarded, so that the process begins again.

Genetic researchers recently have developed ways to hybridize plants faster and with greater control than has been possible with the bees’ method. The new approach uses “genetic marking,” a technique to identify the gene or gene combination that results in a desirable trait in the plant.

The modern hybridizer then crossbreeds plants with desirable traits, grows the resulting seeds, and analyzes the genes in the hybrid to determine if it exhibits the desired trait(s).

A second, related development is the seed chipper, a device that determines if seeds will produce plants with desired traits. This process of “breeding without breeding” greatly speeds conventional hybridization.

Monsanto Company is pioneering the new methods for accelerating and controlling hybridization. These new methods do not involve transferring the genes from one species into another species so they differ from Monsanto’s highly controversial work in genetic engineering.

The new methods have been applied to vegetables: tomatoes, lettuce, peppers, broccoli and onions. Some “super produce” has already appeared in selected markets.

Given the progress of technology, we will see “super ornamentals” in the near future. Today, we can only speculate about how they will look and how they will grow.

New methods, new plants, and new questions!


Basic “how-to” descriptions of the traditional methods for hybridizing plants are readily available. Search the Internet for “hybridizing plants” or a similar phrase. The methods are really the same for all kinds of plants, but find information for specific plants by searching for “hybridizing roses,” inserting the plant name of interest.

For example, the article, “Try Your Hand at Hybridizing Irises,” appeared in Fine Gardening magazine, and was published originally in William Shear’s book The Gardener’s Iris Book (Taunton Press, 2002).

For more information on the new technology for hybridizing, see Ben Paynter’s article, “Monsanto Is Going Organic in a Quest for the Perfect Veggie,” in Wired Magazine, or “Monsanto’s Technology Platform in Wheat,” on the website of Monsanto Company. More detailed information on this technology is available on the Internet. Search Wikipedia or the Internet generally for “marker-assisted selection” or “molecular breeding.”

Inspiring Landscape Ideas

I’ve been pouring through the new edition of the Sunset Western Garden Book of Landscaping: The Complete Guide to Beautiful Paths, Patios, Plantings and More. This book is hot off the press, having been published in February of 2014. It complements the Sunset’s New Western Garden Book (9th edition, February 2012), which is about plants.

The book provides over 600 color photographs of gardens in the western states, with ideas for home gardeners and landscape professionals. It is organized under five headings: Gardens, Structures, Plants, Finishing Touches, and Planning. Each section visits numerous topics, illustrating each in one-to-eight pages of comments and captioned photographs. The text identifies almost all plants that are shown, and the excellent index lists them all as well.

Each topic could motivate the reader to seek detailed information in other sources.

Editor Kathleen Norris Brenzel notes that the book is primarily about inspiration, with an underlying theme of earth-friendly, sustainable design. In a brief introduction, landscape architect William R. Marken defines sustainability as basic to the “new golden age of landscape design,” which has grown out of Thomas Church’s four principles:

  • Unity of house and garden;
  • Function, serving household needs;
  • Simplicity, considering both costs and aesthetics;
  • Scale, relating the parts of the landscape.

Sustainability involves judicious uses of water, fertilizers and pesticides, as well as native plants, earth-friendly materials, and attention to the landscape’s climate, topography, soil and exposure to sun and wind. This book endorses sustainability, but avid gardeners will need other sources for practical advice.

The book’s greatest strength takes the form of striking photographic vignettes of exemplary landscapes. The photos show mostly nicely groomed small areas and even individual plants. Every garden has shortcomings from time to time but why would we want to see those?

The scenes shown in the book are consistently contemporary and relatively upscale, many with pools, lakesides and beachfronts Rather than presenting a documentary exploration of average landscapes, the book offers glimpses of inspirational settings that a reader could translate into his or her own environs.

Consider Church’s Scale principle when installing an assertively modern element in a traditional garden. (A friend recently persuaded me to install a huge surplus mirror in my garden. I like it, but I’m still reflecting on the aesthetics.)

This book is a great source of forward-looking ideas for your home’s landscape, and could encourage a fresh approach to your garden.


To pursue an interest in contemporary landscaping in the western United States, a good place to start is Thomas Dolliver Church’s seminal work, Gardens Are For People (San Francisco: McGraw-Hill Book Co., 1983). This book is widely available in public libraries and in book stores that reserve shelf space for classics as well as today’s best sellers.

A brief introduction to Church’s work as a landscape designer and academician is available the Wikipedia page for Thomas Church. His work included several private residences in Santa Cruz county (including his own home), and overseeing the master landscaping plan for the University of California, Santa Cruz.

Selecting a Landscape Tree

“The best time to plant a tree is twenty years ago. The second-best time is now.”

This is one of many hoary bits of wisdom about gardening. Instead of reviewing more such bits, let’s consider how to select a landscape tree during this year’s dormant period.

The New Sunset Western Garden Book (2012)—always a useful reference—lists four categories of garden trees that not yield edible fruits: patio, shade, flowering and fall foliage.

Patio trees are primarily ornamental, and relatively small and free of troublesome behavior.  Shade trees are larger than patio trees, and typically deciduous. Flowering trees and fall foliage trees also provide shade, but they are selected primarily for their ornamental value.

Landscape trees, depending on size, could be dug as bare root specimens, grown in a plastic container wooden box, or dug and “balled & burlapped.” The larger specimens can be expensive and very heavy to manage, but desirable for achieving an immediate effect in the garden.

Once the gardener has decided on the landscape purpose of the tree and its size at the time of purchase, there are three major criteria for selecting a specific tree.

First, know the tree’s mature size and ensure that it will not outgrow the location you have in mind. The most common error in selecting and planting a tree is to locate it where it eventually will grow to become unwelcome. It might crowd a pathway or driveway, or even the residence. Its might harm other plants by blocking the sunlight with its leaves or absorbing the available moisture with its roots. Choose a tree that will be a good neighbor.

Second, for containerized trees, confirm that the roots have had ample room to grow normally. A tree’s roots should fill no more than 50% of the container; otherwise, the tree could become root-bound, with a long-term threat to its life. I once had a tree service install a large Santa Cruz Cypress (Cupressus abramsiana), an endangered species, only to have it topple months later during a mild windstorm. I discovered that it was severely root-bound, so that its roots could not anchor the tree effectively. Before buying a tree, examine its root structure by pulling the tree from its container.

Thirdly, ensure that the tree’s future location has at least six hours per day of exposure to sunlight, which almost all trees require for health and normal growth. I planted two identical Chilean Myrtle (Luma apiculata) trees, one in full sun, and one too close to an American Sycamore (Platanus occidentalis). Today, the tree growing in the sun is about three times the height of the other tree.

Choose your new landscape tree with care!


The April 2014 issue of Fine Gardening magazine (already on the newsstands and in libraries!) includes an excellent article on this topic. “How to Buy a Tree” by Ed Gregan presents a most thorough discussion of problems that might be encountered with a nursery tree.

I hasten to add that reputable nurseries and garden centers won’t offer trees with significant shortcomings. The owners and managers of well-run retail garden outlets are good people who respect plants and gardening.

Still, it’s possible for a problem to slip through and you could take home a tree that won’t thrive as you, the original grower and the tree itself would prefer. The most common problem is a tree that has become root-bound, after sitting in the garden center or nursery too long. This condition obviously could develop while the manager was not looking!

Ed Gregan’s article is not available online (except for Fine Gardening subscribers), so I can only list his bullet points (below), but you’ll need to read the article for the full story.

  1. Ensure grant points are smaller than a dime
  2. Walk away if there are wounds
  3. Pull off the pot to assess the roots
  4. Strive for a single straight leader
  5. Check under the trunk protector
  6. Look for signs of trouble
  7. Watch out for “coat hangers”
  8. Avoid poor crotches
  9. Avoid even numbers for multistems
  10. If the flare is too high or too low, the tree is a no
  11. Give the ball a thorough inspection
  12. Check for even spacing with clumps


Gardening Science

The Monterey Bay area has an exceptional environment for agriculture, commercial horticulture and residential gardening. The combination of moderate climate, fertile soil and —usually—adequate moisture supports successful growing and attracts expert horticulturists and botanical researchers.

Last week, the 34th annual Eco-Farm Conference drew some 1,200 farmers, scientists and policy makers to Pacific Grove’s Asilomar Conference Grounds to learn from each other and advance the organic food movement another step into the future. We can all appreciate the work of these visionaries to protect our shared environment and produce healthful foods for our dinner tables.

One of the Eco-farm speakers, Michael Phillips, spoke of the holistic cultivation of tree fruits and berries, with clear vision and practical experience. Later, at Cabrillo College, he conducted a 3.5-hour workshop on this subject, sponsored by the Monterey Bay Chapter of the California Rare Fruit Growers. I will discuss his fascinating ideas in a future column.

Cabrillo College presents its own Horticulture Lecture Series in the fall. I will pass along information on the next series when it is announced.

Another local resource for gardeners is the UCSC Arboretum’s Ray Collett Rare & Extraordinary Plants Lecture Series. (Ray Collett was the Arboretum’s founding director.) The most recent talk was given by Tim Miller, PhD candidate in Ecology and Evolutionary Biology, titled “A Brief History of Clarkia: What a Little Annual Flower Can Tell Us About Big Evolutionary Patterns.” Clarkia is a California native plant named for William Clark, who—with Meriwether Lewis—explored the western United States from 1804 to 1806.

One more science-oriented resource is the UCSC Arboretum’s California Naturalist Program. This program, now in its third year, introduces participants to the wonders of California’s unique ecology and engages them in the stewardship of our natural communities. This is an intensive program that combines a science curriculum, guest lecturers, field trips and project-based learning to immerse participants in the natural world of the central coast. Participants are certified as California Naturalists. This year’s program starts on Thursday, April 3rd. The last meeting is Saturday, June 7th. Lectures will be from 7:00- 9:30 pm every Thursday with most field trips on Saturday or Sunday.

Gardening is applied science, as well as aesthetic experience and healthful exercise.
A complete gardening experience includes occasional digs into the sciences.


The Ray Collett Rare & Extraordinary Pllants Lecture Series

Ray Collett Extraordinary Plants Feb-Apr 2014

Future talks (Arboretum Events Calendar)

California Naturalists