Why plants have sex, and why it matters in your garden (Finch)

Bill Finch By Bill Finch Press-Register
on July 22, 2011 at 5:31 AM
Bee azalea flower.JPGView full sizeA bee hovers over blooming azalea plants in the Inner Harbor Park in Ocean Springs in March 2009. Plants produce beautiful, elegant, fragrant flowers for one reason only: To have sex. And the reason they produce flowers to have sex is so that they can make babies. (Press-Register, Jon Hauge)

It is unfortunate that children no longer get a lesson in the birds and the bees.

I know it’s all the fashion to send our children off to school for clinical instruction on the health and social impacts of sex among consenting adults, as if humans alone invented it for their own entertainment and suffering.

But you have to wonder if we might not be a little more sane about it all if we understood it first in that old, roundabout birds-and-bees way, as something every plant and animal had an interest in.

The trouble is, I’m not sure that parents themselves know much about the birds and the bees anymore.

Judging by the recent spate of garden questions I’ve received from reproductive-age humans, I’m tempted to believe there’s an alarming and dangerous ignorance about the most fundamental facts of life. Your children might someday forgive the psychological damage you inflict if you bumble the bee lesson, but your garden may never recover.

So periodically, I take it upon myself to tell you the thing that apparently your parents were too embarrassed or too neglectful to tell you:

Plants have sex. ALL plants do, or at least try to.

And please forgive me for the graphic and coarse nature of the following content, but I must tell you that plants produce beautiful, elegant, fragrant flowers for one reason only: To have sex. And the reason they produce flowers to have sex is so that they can make babies. These babies (call them seeds if you like) are incubated in a womb that is more precisely known as a fruit. Every plant that produces a flower, if that flower is fertilized, produces a fruit of some description — a capsule, a pod, a berry, a husk, an apple, a pear, a plum, a cherry.

Every plant you encounter — trees, shrubs, weeds, grasses — is at some point in its existence going to engage in this kind of scandalous behavior. Shocking, isn’t it?

Even more disturbing, plants have sex and make babies in ways that most people never imagined. While some few plants can be described as male and female, most are genuine hermaphrodites, neither male nor female, but both at once. Most plants have third-party sex. Many have sex that intimately involves insects or other creatures — that’s where the bees fit in, but so, in all honesty, do beetles, flies, wasps, ants, butterflies, moths, and occasionally, even birds and bats. As a matter of fact, if plants aren’t enjoying sex with some insect, they’re more than likely having sex with the breeze. A few desperate plants, particularly those that have been hanging around people for too long, now have sex primarily with themselves. And just in case none of this works, the vast majority of plants have developed various ways of making babies that have nothing at all to do with having sex.

Why would you need to know this? Well, it’s actually rather surprising that gardeners don’t know more about plant sex, because one of the primary entertainments of gardening is watching plants have sex and make babies, or at least try to. In many cases, you’ll need to help your plants have a more satisfying sex life if you want a more productive and attractive garden.

True, there are prudish homeowners who attempt to prohibit all forms of plant sex in their gardens, forbidding anything like a flower or fruit from appearing in the army-green tedium of their yards. But it probably can be safely said that they do not enjoy their yards in the way those of us who more fully appreciate plant sex do.

And regardless of whether you enjoy your yard or simply see it as a desolate moat separating you from your neighbors, failing to understand how plants have sex will leave you frustrated and overwhelmed by the ubiquitous fall-out of their reproductive behavoir, ranging from weeds to allergies to small clouds of buzzing insects.

If you think about this for very long, it could very well revolutionize the way you view your garden. You would not, for example, be in the least surprised to discover that oaks and lawn grasses have flowers, just as roses do. And when a strange cone or globe arises in the middle of your sago palm, unfolding to become what is in essence a very primitive version of a flower, you’d recognize immediately that even plants like pines and cycads bloom and have sex.

Knowing something about plant sex, you might help your female holly find a suitable male mate, at least if you want her to have bouncing, round, red babies. If you were smart about the many ways plants have sex, you’d realize that your blueberry bush, which is neither male nor female, but in fact both at once, doesn’t need a companion of the opposite sex, but it must mate with a distant cousin to produce a good crop of berries.

Fully appreciating the vagaries of plant sex will also help you to understand why you only need one tomato to tango, and why all Southern figs are virgins.

Perhaps, if you understood the basics of plant sex, you wouldn’t worry every spring that the blossoms on your squash plants aren’t producing fruit. You’d appreciate that squash produce separate male and female flowers, and that (who’d have guessed it?) only female flowers bear fruit, and you’d understand fully why the first flowers squash produce are often male.

You’d also immediately recognize that the round hard capsule hanging from your camellia branch is not some kind of disease or plant goiter, but rather the fruit the camellia flower was fashioned to deliver. Open that capsule up, and you’re going to find a seed, or two or three.

Plant that seed carefully, and eventually you’re going to get a seedling camellia.

But before you plant it, it’s good to remember that this seed is the product of sex between two very different camellia parents. And just as human children are never precise copies of their parents, so it’s highly unlikely that the seedling, when it develops and eventually flowers, will look exactly like the plants that produced it. That’s just the simple facts of life.


Do you want to know more about why plants have sex, and why it matters to you, and how understanding and manipulating plant sex can help you to have the most luscious, if not lascivious, garden in your neighborhood?

We’ll introduce you to all these concepts and everything else you need to know to have a great garden in the Mobile Botanical Garden’s Introduction to Gulf Coast Gardening course.

The five two-hour classes included in this program start on Aug. 9 and 10, and will be scheduled every Tuesday afternoon at 1 p.m. or every Wednesday evening at 6:30 p.m. (you choose whichever schedule is most convenient for you).

For more information about these classes, or to sign up, call Dee at the Mobile Botanical Gardens at 251-342-0555.