Cover the stem with plastic or a mason jar. To cover the stem with plastic, insert two eight-inch (20-cm) sticks or wires into the soil on either side of the stem to prop up the plastic. Cover the pot and stem with a clear plastic bag, and affix the bag to the pot with an elastic or twine. With a mason jar, simply place a large mason jar over the stem.
Rose seeds need to go through stratification (an artificial cold spell) for 10 to 12 weeks before they will sprout. This, combined with a germination success rate of 20-30% makes propagation by seed an unattractive prospect. on by seed an unattractive prospect. If you still want to try it, find a good source of information that will guide you through the process.
Chilling your seeds in a refrigerator for about six to ten weeks encourages them to germinate faster once planted. However, you must take care to avoid keeping them cold for long as they can germinate while still in the refrigerator. Place your seeds on a paper towel before moistening them. Use half purified water and half peroxide to prevent the growth of mould. You can then place them in a plastic zippered bag, mark the date and variety before placing in a refrigerator set at 1 to 3 degrees C. The paper towel should remain moist for the entire period. You can check occasionally to see if it needs remoistening. Make sure you don’t freeze the towel.
To start rose bush from cuttings, once the rose cuttings have been taken and brought to the planting site, take out a single cutting and remove the lower leaves only. Make a small slit with a sharp knife on one or two sides of the lower portion of the cutting, not a deep cut but just enough to penetrate the outer layer of the cutting. Dip the lower portion of the cutting into a rooting hormone powder.
I received some seeds as birthday present, the seller included a bonus packet of rose seeds. There’s no indication if they’ve been stratified. If I stratify them now, it will be July when they’re ready to plant. In this region (I’m ~50 miles north of Portland, Oregon)it might be mild or very hot. I’ve read that rose seed won’t sprout if it’s too hot – how well do rose seeds keep? Will they still be viable next Spring, or should i take a chance on the weather and start them now?