Rose seeds are contained inside rose hips, which are the mature ovaries of the rose plant. Once extracted from the rose hips, these seeds may be planted to create seedlings. The timing is crucial. Seeds planted too early will not germinate, or the immature seedlings could die due to frost exposure.
When to Plant
Plant rose seeds when all threat of frost has passed. It should never dip below 18.3 degrees C outdoors if you intend to direct sow your seeds. Otherwise, keep seedlings indoors under a fluorescent light until outdoor temperatures are above 18.3 degrees C consistently.
To collect rose seeds, remove the hips from rose bushes and place them in paper bags. Cut the hips open with a very sharp knife and scoop out the seeds, or place hips into a blender with a little water and process for a minute or two. Then strain the seeds through a fine sieve and dry the pulp on newspapers. Finally, separate the seeds from the pulp and save them for stratification.
Although it is not required, stratification helps seeds come out of their dormant stage and boosts their chances of germinating. The process simulates the natural process of a seed going dormant through winter and warming up in the spring.
The first step in stratification is to place seeds in moist soilless potting mix inside containers. Cover seeds with about 1/2 inch of soil, put a lid on the container, and place them into the refrigerator for three to four months. This will prepare the seeds to germinate.
Once the seeds have been stratified, fill seedling trays at least one inch deep with soilless potting mix. Plant seeds an inch apart, and cover with 1/2 inch of soil mix. Place trays outdoors if the weather is consistently above 18.3 degrees C. Otherwise, keep them in a warm spot indoors underneath fluorescent lighting.
Seedlings will appear between two weeks and several months. Be patient. Transplant seedlings into the garden when they begin to bud. Most plants will have their first blooms approximately six weeks after germination.