Rose propagation can be an interesting hobby for those who enjoy growing these beautiful flowers. To produce plants that are exact duplicates of the parent plant one would propagate roses with cuttings. But rose propagation from seeds can be a fun experiment, even though this propagation method does not produce duplicates of the parent plant.
Fall is a good time to start this rose propagation project, and it is especially good to wait until after a hard freeze to collect the rose hips from your rose plants. If the hips are clipped off the plant before it is dormant, it may encourage the plant to put on tender new growth that could be damaged over winter. It generally takes about four months for rose hips to mature enough to produce viable seeds that would be suitable for rose propagation.
The first step in rose propagation from seed is to gather the rose hips. Rose hips are the round, slightly flattened or elongated seed pods that form when roses are allowed to mature on the plant. If all of the roses have been picked for bouquets, the plant cannot produce rose hips, so if you want to try propagating roses from seed, plan ahead and leave some blooms to mature on the plant.
Depending on the type of rose plant, rose hips will generally turn orange, yellow, red or brown when they are mature. Gather plump rose hips that remain on the plant and do not collect rose hips that have fallen to the ground. Rose hips that have fallen off the plant are generally not useful for rose propagation.
If it is time to gather rose hips but you won’t have time to begin your rose seed propagation experiment right away, whole hips may be stored in the refrigerator for several weeks.
When you are ready to begin the rose propagation process, cut each rose hip in half and remove the seeds. Rose hips may contain anywhere from one to forty seeds per hip. Once the seeds are removed from the hips, rinse off as much of the pulp as you can by gathering a handful of the seeds in your hands and rubbing them together under running water.
Alternately, the seeds can be soaked overnight in a container of water, then rinsed and placed in a food processor. Using the dough-blending attachment, gently mix the seeds to remove the pulp from the seeds. Do not use a sharp blade for this step as it would damage the seeds. Rinse and strain the seeds again after this process.
Once the pulp has been removed, place the seeds in a plastic bag along with some damp peat moss and keep them in a warm room for about four weeks. If some mold appears within the bag, that’s fine. It will help break down the very hard shell of the seeds so they can more easily germinate.
After the four week warm stratification, move the bag of seeds into the refrigerator for another six weeks of cold stratification. This six-week cold stratification is an imitation winter for the seeds.
The next step for rose propagation with seeds is to plant all of the seeds in a flat. Some of the seeds may be showing signs of germination at this point, while others will not. Plant each seed about a half inch deep and an inch apart, using either sand or vermiculite as a planting medium.
Keep the planting medium moist but not soggy while the seeds germinate, and keep them in a fairly cool area where the temperature is about 55 to 60 degrees Fahrenheit. While the seeds are sprouting you may need to spray with a fungicide if any mold develops on the seedlings or the planting medium. Roses are fungus magnets, and lack of disease resistance can be an issue with seed-grown roses.
Some of the seeds will begin to germinate right away, while others may not sprout for two or three months. Germination rates will vary widely, with some cultivars showing a germination rate as low as ten percent and others sprouting at a much higher rate. Rose propagation from seeds is not for the impatient gardener.
When the seedlings develop their first true leaves, they can be potted up. Once potted, give them a weak dose of fertilizer with every other watering. To help deter fungus, water the planting medium and avoid getting the leaves wet with overhead watering. Keep the seedlings in a warm area where the temperature is at least 70 degrees and give them plenty of direct light for sixteen hours each day.
Flower color will also vary, with pink being the most common. Rose propagation from seed is also done by hybridizers, but in that case it is a long, complex process. When done by the home gardener, it is simply a fun experiment that will give you some unique and inexpensive rose plants for your garden.