THE COASTAL GARDENER:

Plants are different than you and I in many ways. I suspect that fact is pretty obvious to even the most plant-phobic people among us.

Yet, there are thousands of moments in every gardener’s life when he or she is inclined to transfer one of our human qualities to a plant. This is the moment when we should be reminded of an important difference between plants and people. Confusion occurs when we ask, “How big does this plant get?”

It is a simple question, with the expectation of a simple answer. But, the answer really isn’t simple at all.

With such an innocent question, one of the most significant differences between flora and fauna is exposed.

Earlier in your life you grew. So did your brothers and sisters, and every human ever born before or after you. You grew at a fairly regular rate until you reached the height that you are today. That is, you grew for about 17, 18 or 19 years. At some point in time you stopped growing, and you haven’t grown since.

But in growth, plants are not like humans. A plant never stops growing; children do. Plants grow every day of their lives. In fact, you can’t stop a living plant from growing. Unlike you and I, a plant has to grow in order to survive; that’s the way they work.

When a plant germinates, most of its leaves and roots are not present yet. It has none of its branches, flowers or fruit either. These will all be created later, many times over. Humans are born complete; plants are not. When we were born we had one head, two arms, two legs, 33 vertebrae, 12 pairs of ribs and so on. No new ones were added later.

More important is how plants grow. Plants grow through the division of cells, primarily at the tips of their shoots and roots. This division creates new leaves for photosynthesis, new roots for the absorption of water and nutrients and flowers and fruit for reproduction.

Humans and most animals stop growing after reaching a pre-determined ideal size. From that point on humans just maintain themselves, never getting any taller and growing no more heads or arms or other parts.

But even under the worst conditions, plants need to grow just to stay alive. That is why even in conditions of severe cold and drought trees still produce growth rings, even though the rings will be closer together because the growth is so slow. It is the reason why tomato plants have been recorded as tall as 65 feet and sunflowers more than 25 feet. Wisterias in Southern California are growing now more than 500 feet in length.

So plants grow forever, until they die. Every plant in your garden is growing right now and will continue to do so until it finally succumbs to a disease, cold weather, old age or some other malady. People have a pre-determined size, and plants do not. Scientists call plants “indeterminate” growers. Humans are called “determinate” growers.

Of course, plants often grow at different rates during different stages of their life. Hence, an old sequoia tree may be growing only a few inches a year, while a young seedling at its feet will grow at a rate many times greater.

Plants vary from animals in many other ways as well. Plants photosynthesize; animals do not. Plants have chlorophyll — or at least the huge majority of them do.

Animals do not. Plants make their own food. Animals prey on other animals or plants in order to get their energy.

So when a novice gardener asks, “how big does that plant get,” the answer is elusive. I usually prefer to say something like, “in five years it should be about 5 feet tall.” Books, articles and gardeners will forever list sizes for plants, and they should, since we all need some sort of common reference point, but it is only a guide.

You know your 5-year-old son will grow to be about 6 feet tall, more or less. When pointing to a shrub and asking “how big does that plant get,” the answer isn’t so easy.

ASK RON

Question: I was told that I shouldn’t plant a Brazilian pepper tree because it can reseed easily and is causing environmental problems in Upper Newport Bay. What do you think?

Shirley

Newport Beach

Answer: I agree. Brazilian pepper trees (Schinus terebinthifolius) were a very popular tree in Southern California for many years, but their popularity has declined recently, partly due to their invasive nature. These trees have invaded Upper Newport Bay and many other coastal canyons and wild areas of Orange County and have displaced our native vegetation. In fact, it is illegal to posses or cultivate a Brazilian pepper in the state of Florida because of the huge problems it is causing there. There are many other trees that would be a better choice.

ASK RON your toughest gardening questions, and the expert nursery staff at Roger’s Gardens will come up with an answer. Please include your name, phone number and city, and limit queries to 30 words or fewer. E-mail stumpthegardener@rogersgardens.com, or write to Plant Talk at Roger’s Gardens, 2301 San Joaquin Hills Road, Corona del Mar, CA 92625.

RON VANDERHOFF is the nursery manager at Roger’s Gardens in Corona del Mar.