by David Clark, CNLP
If you want to try to start roses from seed, autumn is the time to do it.
However, because of cross-pollination, there is no guarantee that the plant you get from those seeds will flower true; that is, those seeds may not produce the same kind of flower that your original plant produced. On the other hand, you may find a new and exciting variety!
What are rose hips?
The rose hip is the fruit of the plant. It will be a green or red ball that forms when the flower drops off.
Collect the hips in the fall, once they have softened and feel squishy.
Harvesting the rose seeds
Squeeze the rose hip pulp with the seeds into a small bowl filled with water. Swish the pulp around to remove the pulp from the seeds. Pour off the water, saving the seeds.
Next fill a one-cup measuring cup with water to the one-cup line and add a teaspoon of bleach. This will be used to sterilize the seeds.
Add the seeds to the bleach water and let them sit for about 20 seconds to sterilize them. Pour the bleach water solution plus seeds into a fine kitchen strainer lined with cheese cloth or gauze and rinse well with clear tap water.
Expose the seeds to cold temps
Next we have to stratify the seeds to mimic outdoor weather. Get a small plastic lunch bag, put in a small amount of dampened peat moss and add the seeds. Seal and mark the bag with that day’s date and then a date 60 days into the future.
Keep the bag at 35 degrees Fahrenheit for the 60-day period.
Plant the rose seeds
Get a four-inch plant pot and fill it with sterile soil-less seed-starting soil. Plant the seeds about one-quarter inch deep.
Place the pot in a very bright area or under grow lights and keep the soil moist. The seeds should germinate in about two to six weeks.
Grow the seedlings on until they have at least two sets of true leaves. At that point, they can either be potted up separately and grown on, or planted outdoors once the threat of frost has passed.
About David Clark: A nationally and internationally known gardening educator, David Clark teaches a series of horticulture classes at the Buffalo and Erie County Botanical Gardens. He can also speak to your group. Find out more here.