Roseseed (notes on growing roses from seed). I will add pictures later.
Cut the fruit from the plants when they are ready probably when they are pink or red, like a fresh apple
wash the fruit and cut in half.
remove the pointy white seeds
there maybe as many as 50 seeds or as few as 1.
Wash seeds in a strainer.
Rose seeds can be sown right away, but germination may be more successful if placed in a refridgerator in a plastic bag between layers of moist paper toweling for 6 to 8 weeks first.
This process simulates the conditions the seeds would go through in winter (called stratification). You can use tweezers to remove the seeds from the paper.
Use a sterilized soiless potting medium to avoid damping off fungus.
I fill one of our 1 gallon pots with our sterilized soiless potting mix (actually I usually do this to a bunch of pots labeling them as to what they are on the side with a paint pen and the date), spreading the seed and covering them with about a half inch more soil.
I place each pot in a 2 gallon ziplock bag so the air inside is kept humid but if moisture forms on the bag I can easily open the bag for a short time and reseal.
Then I place these pots inside one of my insulated cold boxes for the winter so the seed gets stratified the bottom of the pot firmly on soil in the bottom of the box so warmth from the ground can be conducted up into the pot. In spring the seedlings in a pot remain with all the rooted cuttings in the coldframe.
Temperatures are best between 50 and 60 F. Bright light but not full sun, or under gro-lights that are lit continuously. When you see the two leaves of cotyledons remove from the bag or at least leave it open or only partially shut.
You can add a water soluble fertilizer at half strength.
When they have prooduced three sets of leaves you can transplant but we usually wait until they are a bit older and divide the crowded little buggers.