Most of the roses we buy at nurseries or exchange with each other have been vegetatively propagated, either by budding/grafting onto a rootstock, or by rooting cuttings (own-root). Yet each of those varieties, at some point in the past, sprouted from a seed, or was a sport of a variety grown from seed.
Roses are not difficult to grow from seed, if you do it right. If you just put a lot of seeds in a pot of soil, water it, and wait, you'll likely be disappointed. But by using the procedure explained here, you should be able to grow them.
First, be aware that each rose seedling is a new, never-before-seen variety. If you plant seeds of 'Don Juan', you will get climbers, large bushes, small bushes, in a variety of colors, with a variety of scents, etc. What you can be completely sure of, though, is that you will not grow another plant of 'Don Juan'. That's true of any variety from which you collect the seed; they don't "come true" to the original type. The probability of your coming up with the next AARS winner is not very good. Kind of like winning at Lotto. However, among the many poor quality seedlings, you will likely produce some plants that you find interesting, and which may be well worth growing.
You can make your own hybrids, selecting both parents, carefully transferring pollen, etc. I'll not go into that process in this article. An easier way, which can also produce interesting results, is just to let the bees in your garden take care of the pollination. In this case, you'll get what are called "open-pollinated" seed, and you'll know with certainty the identity only of the female parent, from which you'll collect the seeds.
Rose seeds are produced inside the "hips," the fruit of the rose. If you zealously dead-head your roses, you'll not get any hips, since they are produced from the old flowers. Some varieties seldom, if ever, produce hips; others are good producers. In our gardens, 'Don Juan', 'Carefree Beauty', 'Bailey Red', 'Bermuda's Kathleen', 'Dortmund', 'Kathleen', 'Penelope', 'Ballerina', 'Apricot Nectar', and the single musk rose (R. moschata) are particularly good producers.
In the late summer or fall, collect hips that have ripened -- they'll usually be yellow, orange, or red. Cut them open with a knife, and shell out the creamy white "seeds." These are technically "achenes," each of which has the true seed inside, but for practical purposes of growing them, we can think of them as seeds.
Most roses come from colder climates than Florida, and their seeds are programmed to survive a winter before they sprout. We can trick them into sprouting by giving them a "stratification" treatment -- a period of moist, cold storage. Rinse the seeds if they have a lot of fruit pulp on them, and wrap them in a moist paper towel. Place that packet into a zip-loc bag, and place it in the refrigerator (not the freezer). Be sure to include a label, indicating the parent variety and the date. Don't feed it to the dog or the spouse, as left-overs... After 4 or 5 weeks, start checking on the seeds every week or two. At some point, you'll notice little root tips poking out of some of the seeds. Carefully transfer these to pots of soil, cover them with about 1/4 inch of soil, water them in, and keep them at room temperature. They should emerge in a few days. Be careful in transferring them since they are quite fragile, and they tend to stick to the paper towel. It's very easy to break the root off of the seed. I use a blunt pair of tweezers for this process. Put the unsprouted seeds back in the refrigerator for another week or two, and check them again. Depending on the variety, seeds may continue to sprout for several months. So you'll likely make several transfers to warm soil, over that period.
Very young rose seedlings are quite susceptible to damping-off, a disease in which the stem rots at the soil surface. Avoid it by using a sterile planting soil to start with, not overwatering, and if you like, use a copper-based fungicide right after the plants come up. Another common problem with rose seedlings is that a high percentage of them will be highly susceptible to powdery mildew. It's probably best to discard those plants, since they'll not likely become resistant later in life. Keep the robust, healthy seedlings instead.
If the seeds' parents were both repeat-flowering varieties, the seedlings can flower in as little as 5 or 6 weeks after planting. They'll almost certainly flower in the first season. If either parent was once-flowering, however, the seedlings may not flower in the first year, and some may wait 3 years or even more to flower for the first time.
Growing your own rose seedlings is an interesting side-line to the hobby of growing roses in the garden. Have fun with it.
Copyright Dr. Malcolm Manners, 2000.