You must monitor the seedlings as they grow in their new pots for colour, form, bush size, branching, and disease resistance. Roses with weak, unhealthy or unattractive flowers can be discarded. It will take your new seedlings at least three years before they reach maturity and develop into a big bush. However, the first flower can be seen after one or two years.
The ripened rose hip is then placed on a clean cutting board and cut in half to remove the seeds. Place the seeds in a clean container. Add some diluted bleach to kill off any bacteria and fungus spores. You can make the bleach by mixing drinking water with two teaspoons of household bleach. Stir the seeds well before rinsing them and using bottled water to remove all the bleach. To further clean and disinfect the seeds, put them in the container and add some hydrogen peroxide. The seeds can be soaked for up to 24 hours before rinsing them with clean water to clear all the hydrogen peroxide.
Most softwood rose cuttings will root within 10 to 14 days.1 To test their progress, tug very gently on the cuttings. You'll feel a slight resistance as the new roots form and grow into the soil. A gentle fish- or kelp-based fertilizer during this time provides beneficial nutrients. Once roots are established and plants show strong new growth, you can transplant your new roses to more permanent garden homes.
Cover the cutting loosely, pot and all, with a plastic bag or plastic wrap and keep the soil moist. Putting a tall stake into the pot will hold the plastic away from the leaves. If the plastic touches the leaves, they remain wet and can succumb to a fungus disease. Along the same lines, make sure the condensation can escape from the plastic or the stem will rot.
There will be disappointments along the way, when many rose seeds fail to germinate, or perhaps they do germinate, only to die several weeks later from damp-off disease. Sometimes a rose seedling will turn out to be as ugly as sin, or very sickly, and you will reluctantly have to throw it away. Other times they will be just ho-hum, or look too much like its parent, and therefore have no value. But, just when you don't expect it, you might discover that one of your rose seedlings turns out to be very special.