Publications (Paul's Blog)

August 25, 2009

HYBRIDS VS. HEIRLOOMS

Filed under: Uncategorized — Paul Dowlearn @ 6:56 pm

In recent years, there has been a massive reawakening in using heirloom plants in the home landscape. The are several reasons for this, including nostalgia, but the main attraction is simply survival. It seems folks are turning back to the older varieties because they are hardier, more drought tolerant, and generally resistant to insects and disease. In years past, the exact opposite held true as far as popularity is concerned. Gardeners were scrambling to acquire the latest hybrids in hopes that these were somehow better plants. As a result, growers put the old standard varieties on the back burner to make room for the new.

While there are still a good number of folks who anxiously await the new releases each year the love affair with heirloom varieties is definitely blossoming so we are beginning to see growers offering these plants once again. Understanding what this trend is all about comes with knowing what plant breeders actually do and what their goals are. The term hybrid refers to “high breeding” which is what happens when you take closely related species and breed them together resulting in a new breed or species. For example, a horse bred with a donkey will create a mule. A mule is bigger and stronger than most horses or donkeys therefore making mules better at packing or pulling heavy loads. The drawback is mules are sterile. Keep this hh01in mind as we apply this to plants. Sterility is one of the things Nature does to protect the integrity of the genetic code of separate species. When it comes to plant breeding, the term hybrid is often a misnomer as plant breeders are usually working with cultivars of the same species. In many cases individual cultivars are bred back into themselves. This is called back breeding. When this happens in the world of humans and animals it is called in-breeding. We all know the tragic results of in-breeding.

What happens when plants are repeatedly bred back into themselves is quite similar to in-breeding animals. The gene pool becomes “shallow” as certain traits dominate and others recede. The plant becomes sterile, weak, and far less likely to survive without help from the gardener. In the worst cases what you get is a really pretty plant that is an absolute wimp. Up until recent times the goals of plant breeders were to “improve” the plant by creating different flower colors, growth habit, more flowers/fruit, bigger flowers/fruit, or leaf colors. This was great for creating new cultivars but had nothing to do with making the plant stronger or easier to grow. It was only during the latter half of the past century that keen interest was shown in developing plant cultivars for drought tolerance, cold hardiness, and resistance to insects or disease. Of course in the beginning, attempts at selective plant breeding usually gave positive results. Most in fact were quite positive. Selective breeding of staple crops like corn and wheat were likely begun by ancient peoples long before any written records were kept.

The modern versions today bear little resemblance to their wild ancestors. In fact nearly all the grains, fruits, and vegetables we consume today are hybrids. On the other hand, in today’s horticulture industry there are a frightening number of different hybridized plants to choose from. There are literally thousands of different roses, iris, crepe myrtles, tulips, daylillies, tomato varieties, and so forth. This can be bewildering to the average person who develops an interest in gardening. All these different varieties are certainly not equal. Which are best? Let’s use roses as an example since the rose is quite possibly the all time favorite of most people and probably has more existing species and cultivars in the trade. Common knowledge has it that roses have become increasingly hard to grow. Some of the new cultivars make bigger blooms but they have lost that wonderful scent. Others smell great and bloom well but are continually consumed by blackspot or powdery mildew. When we manage to cure that then they are attacked by aphids or some other critter.Still others have been bred down to be cute, dainty little things but won’t live outdoors without constant vigilance. While we are at it……….just think about how many “tree roses” you have seen that actually lived beyond the first year or two. Been there…….done that.

So now we have a new generation of gardeners who exclaim “I would love to have a rose garden, but they are just too hard to grow!” Nothing could be further from the truth. Our wild native roses are among the toughest plants found in Nature. So what happened? In our lust to create more forms, more colors, miniatures, and what have you, we bred roses into each other so many times that they lost a certain amount of their good genes that would have made them strong, vigorous plants. Enter the “antique” rose. Antique roses are simply older roses that still retain those stronger genetics from their wild ancestors. In the earlier days roses were being selectively bred while new species that were discovered in the wild were hybridized (in the true sense of the word) into the cultivatedhh02 forms. This means that in general antique roses are inherently much easier to grow than their newer in-bred cousins. They also tend to have more blooms, bloom more often, resist insects, shrug off disease, and most retain that wonderful aroma. Many antique roses were “rediscovered” growing in old cemeteries, abandoned farm houses, and along fence lines. These had not had the benefit of water and fertilizer for decades yet they not only survived, they thrived. Due to the combined efforts of old rose enthusiasts and a few nurseries that came to specialize in antiques, we now have many of our heirloom roses back in the trade. Another bit of good news is that some of the roses that have been hybridized recently are getting bred with heirloom varieties to gain back that extra vigor.

Today we can say that basically any rose that was bred before the 1900’s or thereabouts is an heirloom and a good choice for easy care. Also, a good number of the roses released since the 1980’s are new cultivars of heirloom varieties. The roses that gave rose culture a bad name were the grafted varieties and in-bred wimps created by the insatiable appetite for something different. The same holds true of most of our popular plant varieties. Whenever there are hundreds or even thousands of named cultivars on the market, it’s a safe bet that a certain amount of back breeding (in-breeding) has occurred. If you are lucky enough to acquire some old “species” tulips you will find that they will return to bloom again for many seasons. Unfortunately most of the tulips that will be bought and planted this winter will do no such thing. Just as we have bred chickens that lay huge amounts of eggs but no longer have the basic instinct to set and hatch those eggs, the nursery industry has bred thousands of plants that have no chance of survival without a greenhouse or a very diligent gardener.

Now if all this is beginning to make sense then the next logical question is: ” How does one know the difference?” The answer is that without asking a lot questions you don’t. A trusted gardening friend or a well informed nurseryman may know the answer. Otherwise you are stuck with trial and error or studying horticulture yourself. The main point though is to simply realize that the true native version of any cultivated plant species is going to be the best choice when it comes to livability. I hope this article hasn’t muddied the water but instead cleared things up a bit for some of you. Many would-be gardeners give up too quickly and resign to be a brown thumb for life simply because the plants they found attractive enough to attempt to grow are in-bred hybrids.

A rose is NOT a rose by any other name, in this case. Some are easy to grow, others are not. Personally, I’m mighty proud of my old fashioned orange daylilies, the iris handed down from my grandma, and my reseeding petunias. Lately I’ve acquired some of the old Byzantine gladioli. I can’t wait to get some out to the house and turn them loose. At my house, the only intensive gardening takes place in the vegetable patch. Otherwise, if you are a rose (or whatever), you may get some extra water to get established and perhaps during a serious drought, or some mulch going into winter. That’s about it. If you die you are going to be replaced…………most likely with a tried and true heirloom variety. -Paul Dowlearn

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