RAZOR BLADES.
I have success rooting about 80% of my rose clippings. I am sure all of the tricks in various threads help but there is one missing critical piece. The cut needs to be super clean. I use a razor blade at a 45 degree angle.
The outer skin carries water and minerals up the stem. When you have a rough cut, it squeezes closed the little capillaries at the cut end. Imagine cutting a straw. If you use a dull knife or your teeth, it's going to mangle the end of the straw, and it won't be very easy to suck liquid through it. If you use a razor sharp set of scissors, you get a nice clean cut with an open end. The same goes for your water carrying vessels in the rose stem.
Key tips:
1. Razor cut at 45 degrees.
2. Gooey rooting hormone on the end.
3. Break off the leaves and thorns along the part of the stem to plant, and apply root hormone all along that area.
4. Use stems that have just flowered.
5. Use larger stems, and even canes.
6. Use longer stems. They die slowly from the top but don't give up on them until they are dead all the way to the ground. I use stems at least 12" long, and go up to 4' sometimes.
7. Preset the hole with a skinny object, and then gently push the cut end 5" or 6" deep. Again, we are trying not to bungle the cut end.
8. Set up drip irrigation directly on the stem, or at least make sure the soil gets very wet around the cutting every day.
9. Try after the first blooms, but later blooms work too.
I don't bother with the jar or 2 liter bottle covering, but it doesn't hurt.
Regular strong sun.
