Hybridizing at HVH

'Renaissance Blue' had a beautiful Flower but the plant was difficult to grow and the flower faded in heat.

Some of you may wonder where the new varieties we introduce come from - for example, in 2010 there are 41 brand new ones never seen before. Others of you know where they come from, but might wonder why these particular ones out of many hundreds of new ones were chosen for the online store.

Hybrids

Hibiscus rosa-sinensis, the tropical hibiscus that we specialize in, is ideally suited for creating new varieties. New varieties are actually hybrids of earlier hybrids that themselves were made by cross-pollination of two of the seven compatible species of hibiscus found around the world. Since these 7 cross-compatible species carry different genes, we now have an abundance of genetic material to work with. Making new varieties means shuffling the genes of existing varieties around in an almost infinite number of combinations. As you might expect, we try to include desirable genes, and exclude undesirable genes, in order to find new combinations of genes that give us the flower colors and size we want, as well as optimum bush and growth characteristics.

How We Do It

'Night Magic' has replaced 'Renaissance Blue' with a similar flower on a lush easy-to-grow bush that blooms more profusely and holds its color in heat.

To create these new varieties, we must cross-pollinate many blooms of different varieties, grow the seeds that come from this cross-pollination for a year or longer, observe the first flowers and the growth habit of the bush, and then successfully propagate more plants using cuttings or grafts taken from the original seed-grown plant.

We spend many hours planning which flowers to cross with each other, and then begin by spreading the pollen of one variety onto the staminal pads of another variety. We repeat this process for each new "cross" that we want to make. For the process to result in viable seeds, the pollen grains must sprout a long tube that travels down the staminal column into the base of the flower where genetic material from the 2 varieties is combined to make seeds. As many as 40 seeds are possible from one cross, but the average is closer to 10. Each of these 10 seeds will contain genes that are unique, each different from the other, just the way each human baby is unique even though several babies may have the same parents. The process is not always successful. Both pollen and pads must be moist and fresh, and many hibiscus do not set seeds well if at all. Many crosses that we want to make cannot be done since neither variety will make seeds. Most varieties do make viable pollen, which is helpful. Some varieties do not match in the number of chromosomes they have and crosses between them are also unsuccessful.

'Gold Mine' had a beautiful Flower on a bush that was a bit unruly.

However, when a cross takes, the seed pods ripen and grow nice black seeds, about the size of grape seeds, which are ready to be planted. Not all the seeds will sprout and grow successfully, but those that do are carefully tended to as they grow and mature. After a year, more or less, the big day comes when the seedling plant finally flowers. Sad to say, but most of the first flowers show us that we were not successful in getting something unique and better than what we already have. We watch the plant open several more blooms and if in doubt may watch for an entire blooming season. But eventually we reject a high percentage of the seed-grown plants as not being the improvement we hoped for. These plants are destroyed so as not to contaminate the hibiscus gene pool with inferior or flawed plants.

That leaves the tiny percent of seed grown-plants that do show us something special. As you might imagine, those are very rewarding! Our next step is to take cuttings from these promising seedlings, and grow new plants to test. Plants grown from seed can have a very different appearance and habit than when that same potential new variety is grown from a cutting. Some "wood" is cut from the branches of the seed grown plant and then is either stuck in conditions where it will root and form a new plant with identical genes as the seed grown plant, or it is grafted onto a special type of hibiscus known as a root-stock plant where it will also grow into a genetically identical plant as the seed grown plant. We grow several plants in these ways and hope for the best. If all goes well, the potential new variety will grow vigorously into a strong, upright bush that branches well either naturally or in response to pinching the growing tips. It will begin to flower in a reasonable time, and continue blooming steadily, or better yet, profusely. We also watch to see if the flowers are presented well on the bush so that they are visible, as opposed to hanging downward. We prefer bushes that are attractive and that display attractive leaves that give the bush a full appearance. There are many other qualities we look for, but these are the primary ones. If a potential new variety displays these traits, then we are well on the way to producing a new named variety, also called a cultivar, short for cultivated variety.

'Venetian Brick' has replaced 'Gold Mine' with a similar flower on a strong, beautiful, easy-to-grow bush that blooms much more profusely.

All the HVH named varieties, including the new ones being introduced for 2010, passed through the above steps. All the cultivars we grow represent only 2 percent of all the hibiscus we have grown from seeds over the last 15 years. That is why they are so special! Out of the many thousands of times we have rolled the dice, genetically speaking, these 150 or so cultivars offered in the online store are the best of the best.

Tried and True