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Hybridizing Your Own Roses

Why hybridize your own roses? If you enjoy something in your garden that is totally unique, this is one way to get it. For starters rose breeding is kind of fun but do be forewarned, it can easily become addictive. Consider this: every single rose seedling you grow will be totally unique. Each will be one of a kind, and until you asexually propagate that particular seedling with cuttings, grafting or budding, you'll have the only one in existence. Did you ever wish you had a fabulous rosebush that no one else had? Ever think that it would be pretty neat to have a new rose that you could name for your mother, your wife, your favorite auntie, or maybe your daughter or granddaughter? If you breed a new rose, you do get to name it.

Before I get into exactly how I hybridize roses let's see if we can get clear on what a hybrid is. People often confuse hybridizing with grafting and budding but they are totally different procedures. A hybrid is a sexual cross between two related but different plants. A hybrid between two very pure strains is often called an F1 hybrid and it is apt to have "hybrid vigor," if you're lucky.

Roses are actually fairly easy to hybridize--- if you know how to go about it. For years I used to try to make crosses, all of them unsuccessful, until at last I got some decent advice.

Pollen from one plant (the "stud" or "pollen Parent") is collected and then this pollen is used to fertilize (pollinate) the female parts (the pistil) of a different plant (the "mother" or "seed parent"). The plants must be fairly well related to get the cross to take. For example you could successfully cross a plum with an apricot (getting a "plumcot"), but trying to cross a plum with an apple would almost certainly fail.

Modern roses, especially the hybrid tea roses, have extremely complex pedigrees. Gardeners who like to monkey around like this have been crossing these roses for hundreds of years now. As a result of all this cross breeding, all of our modern hybrid tea roses come from a very wide and diverse background. Thus, when you cross one tea rose with a different rose, the possible variation among the resulting seedlings is enormous. This makes rose breeding a crapshoot of sorts, a wild, and crazy gamble at best. You just don't know what you'll get, but this also makes it all the more interesting.

Disease Resistance

Most of our modern hybrid tea roses were bred mainly for their flowers. Breeders were looking for, and found, big, bold, beautiful roses. What they bred for much less was disease resistance. As a result many, if not most, of our modern roses are sorely lacking in disease resistance. When I first started to breed my own roses I too just bred for color and size. As a result I usually got weak plants that were totally susceptible to mildew, rust and blackspot. Hybridizing tends to bring out both the best and more often the worst traits of the parent plants. As a result you will get far more inferior seedlings than you'll get nice ones. But if you make enough crosses, every now and then you will get one you'll just love.

I now try and make crosses that combine size, color and beauty (and fragrance) with a rose known for strength, vigor and disease resistance. I'm getting much better roses too as a result.

Getting the Big Bucks?

It isn't likely at all but it is possible, that you could make a cross and come up with a new rose that just flat out knocks everyone's socks off. An amateur backyard breeder did breed the fine big yellow-green rose, St Patrick's. If you did come up with a real winner, it is possible to contact one of the large rose companies and ask them to have a look at it. If they like it enough they might well propose a deal with you to grow it, sell it, and share the royalties with you. Patents on roses now last for twenty years.

Not for the Impatient Gardener

From the time you make your first cross to the time you actually see a blooming rose from your efforts, a year or more can easily pass. Breeding roses takes some patience. The advice below is not the only way to breed roses, other people have their own methods. This is simply how I do it.

Best Time to Hybridize

I've found that the crosses I make in the months of March, April and May have by far the biggest "takes." This will vary from one area to another of course, but in general, you'll have the most success making your crosses early in the growing season.

The Steps

First you need to deciding which rose bush you'll use as the male (the stud), and which as the female (the seed parent). Keep in mind that if you know that one of them makes large rose hips, this might be the better choice for the seed parent. You'll get more seeds this way. A few types of roses make very small hips with very few seeds. These would generally be better choices for pollen parents.

Not always, but often, the rose bush you choose for the seed parent will exert more influence on what form the resulting plants take. The seed parent will usually have more influence on the size and shape of the leaves, the size of the plant itself, and whether it grows as a bush, climber or groundcover type. The stud or pollen parent will often have more influence over the size and color of the flowers, the shape of the flowers, how much or little fragrance they will have, and how many petals each flower has.

How to get started:

First, you need to decide, what it is you are looking for? What kind of a new rose would you really like to create? Look at some roses and think to yourself, if I crossed this one with that one, what might I get? In truth, you will get what you will get and it may not be anything like what you had in mind. Still, in the beginning it helps to have a goal, some ideal you are shooting for. To add more satisfaction to this whole procedure keep a log too. Make notes about which crosses you made on which date, and what you were thinking, what you were hoping to come up with.

The Stud Rose

For the stud rose, the pollen parent, pick several roses from the plant you want as your stud. Ideal roses for this purpose will be well past the closed bud stage, but will not yet have actually opened. Once they have opened they usually yield less, if any, useable pollen. Pick the roses leaving a few inches of stem on each. Remove all of the petals and also the sepals that are just below the petals. Now, take these flowers and set them on a piece of white paper, inside your house, away from any direct sunlight. On the paper write with a pen or pencil, the name of the stud rose.

If you like you can pick a number of different roses to try as studs. Be sure to give each of them some room on the paper, so that they don't touch. Write the name of each one on the paper and then set the petal-less flower on the name.

You will let the stud roses you have picked sit there on the paper for about 24 hours. After they have been there for a day, you can pick up each one by the stem, and lightly tap it on the paper. If it is a suitable stud, you will get a small pile of pollen. Occasionally though, if the humidity is high, it may take several days for these to be ready. The pollen is usually yellow but this color can vary from one cultivar to another. Let that pollen just sit there for a moment.

The Seed Parent or the Mother Plant:

On the seed parent you will look for roses that are ready to cross. Ideal candidates are roses that are well past the bud stage but are not yet open. If you were to squeeze one of these roses gently, you'll feel considerable give in it. If you squeeze it and it still feels perfectly solid, it is not ripe enough yet to cross.

Once you pick the rose you want to cross, to hybridize, carefully remove all the petals from the flower. If you like you can also carefully remove all of the male stamens. If you do this and a cross results you can be assured that it is indeed a cross, not a selfing (where the flower simply bred itself). At this time the pollen on the tips of the stamens is not yet viable so you need not worry about self-pollinated the flower.

But, you do not need to remove all or any of the stamens. I generally don't bother. I have found that leaving the stamens in place puts less stress on the flower and results in a higher take. It may also result in some seeds that are not actually the cross I intended, but I generally don't worry about this.

Now, in the direct center of the flower are the female parts, contained in the pistil. The very tip of the pistil is the stigma. If the stigma is slightly sticky you are in luck.

Go back in the house and gently place the tip of your finger in the pollen on the paper. The pollen will readily stick to the tip of your finger. Now, go back outside, being careful not to touch anything with your pollen-tipped finger.

Carefully dab the pollen on your fingertip right on the exposed stigma of the seed parent flower. Try to get pollen on the entire stigma. If the pollen sticks and stays, it is a good sign, and you may well have just initiated a hybrid cross. In effect here, this is plant sexual reproduction (was it good for you?) and you are the honeybee.

If the pollen doesn't stick to the stigma as well as you'd like, you can come back later in an hour or so and try and put a little more pollen on it.

Now, some folks will cover up the crossed rose with a paper bag so as to keep out any insects and the pollen they might bring. I hardly ever bother to do this though. Next, take some sort of a tag, put a small hole in one end of it so that you can put a wire through it. On the tag, with a pencil, NOT a pen, write the name of the stud used and the date you made the cross. You do not need to put the name of the seed parent on this tag, since you'll know what it is just by looking at it.

The Wait:

Make as many crosses as you like, the more the merrier. You will quickly find that some roses yield lots of pollen and make great studs, while others yield almost none.

Once your crosses are done you just wait and see if they took, if pollination actually took place. If all goes well a rose hip will start to form. If the cross did not take the hip will not form and the flower will just shrivel up and die. If you get a take of 20 to 30 percent, you are doing pretty well.

It takes months for the hips to form and ripen. You will not pick them until they have started to change color, to red or orange. You do not need to wait until they are fully colored though.

You now pick the hip, cut it in half with a sharp knife, and pick out the seeds. Clean each seed carefully, removing every bit of rose hip from it. If you leave some of the hip attached to the seed it will be much slower to germinate. Rose seeds come in all sizes and shapes and the good, viable ones are solid and hard. In each hip you may find as few as one or two hybrid seeds, or you could find as many as 30 or more.

Stratification of the Seed:

The seed will need a cold treatment in your refrigerator. What I do is I put the cleaned seeds in a plastic baggie, along with a tag that tells me the names of the stud and the seed parent. I always put the name of the stud first and pollen parent second. Thus if I had crossed a 'Peace' rose with pollen from a 'Sterling Silver' I would write on the tag, 'Sterling Silver' x 'Peace.'

I leave a piece of moist paper towel inside the baggie with the seeds and I do not close the baggie. I write down on a calendar the day I put each batch of seed in the refrigerator. I leave the seeds in the refrigerator for at least 6 weeks and sometimes for as long as 3 months. I check them now and then to make sure they are not getting too dry, or moldy. If some mold does start to grow on any of the seed, I just wash it off and put them back in the refrigerator. Mind you, I do NOT put the seeds in the freezer.

Germinating the Seed:

I plant the rose seeds in flats if I have a lot of seed, or in small pots if I have less. I use potting soil to which I have added some 3-month time-release fertilizer and some additional perlite. Make sure to properly tag your seed containers.

I plant the seeds shallowly, barely covering them. Occasionally I dust the flats with a fungicide power but more often I do not. The seeds need fluctuating temperatures to germinate well, so the flats or pots are best kept outside. If it is still freezing in your area at this time, you can put the seed containers in a sunny windowsill.

The seed will germinate, depending on the crosses made, in as quickly as 3 weeks or as slowly as a year. Most seeds that sprout will come up in about 4 to 6 weeks. Germination rates are almost always poor with rose seed, so if you get even 20% of them to sprout and grow, consider yourself lucky. Remember, rose hybridizing is not for the impatient and the faint of heart!

Growing the Seedlings:

Some rose seedlings grow strong and fast while others grow very slowly. Rose seedlings need direct sunlight. Expect great variation in growth among your seedlings, even those from the same crosses. I like to spray my rose seedling at least once a week with a mild fungicide, more often if needed. If you prefer to be more organic, use a spray mix of 4 tablespoons of baking soda to a gallon of water as your fungicide. If needed, protect the seedlings from insects such as aphids.

When your seedlings have several true leaves, start to fertilize them once a week with a weak solution of water-soluble fertilizer. Keep the seedlings well fertilized.

When the seedlings are a few inches tall you should transplant them each to its own little pot. Never put a tiny plant in a large pot. Use two-inch pots for the first transplant. If the seedling start to outgrow these, step them up to 4-inch pots. Usually by the time the new rose seedlings are 6 to 8 inches tall they will bloom and form their first flower. Usually this will be one single rose. Exceptions will be roses that had climbing roses as parents, as these may need to get a foot or more tall before they will bloom the first time.

The first flower is what you are looking for! Because it is borne on such a small plant the size of the flower may well be smaller than they will eventually be. But, the color, the number of petals in each flower, the shape of the bud, the shape of the full rose, the fragrance or lack of it, all these will be perfectly apparent. You will now have a pretty good idea how special that particular seedling of yours is, or isn't.

Take the seedlings you like and plant them in a raised bed and grow them on. Eventually you can propagate more of any of the ones you especially like by making cuttings, or by budding them onto another rose. All the recognized names of individual rose cultivars are to be found in the book, Modern Roses Ten, which is published and updated every few years by the American Rose Society. If you get into this you'll eventually want to own your own copy. Before you pick a name for your new favorite rose, check to see if that name has been used and if it is still in use.

Consider joining the American Rose Society. Their monthly magazine is a real treat for rose lovers. The ARS's website is http://www.ars.org/

Consider too, joining the RHA, the Rose Hybridizer's Association. Membership is only $10 US per year and is well worth the investment. They have a quarterly newsletter with useful and interesting information on breeding roses. Make your check for RHA membership to the Rose Hybridizer's Association and send it to: Rose Hybridizer's Association, Larry D. Peterson, RHA Sec-Treasurer 21 South Wheaton Road, Horseheads, NY 14845-1077

Another interesting website for rose breeders is The Rose Hybridizer's Group, at http://www.olyrose.org/hybridizing.htm

 
 
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