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.
The Baggie Method: This was the first method I ever tried. Here you fill 2-inch plastic pots with potting soil, insert the rose stem halfway inside the pot, then put the pots into a one-gallon plastic zip-lock bag. You can get four 2-inch pots into each gallon bag. I didn't like this method because it caused many of the cuttings to rot since the bags tended to fold over and therefore prevented the air from circulating. The success rate of this method is not very good. It may be helpful to place a couple of small sticks inside the bag to help keep it upright and full of air.
Fertilize the roses. After they are established, roses should be fertilized a few times per growing season. Use fertilizer (either liquid or granule) in early spring, when you see the first few leaves sprout. Use it again after the first bloom, and again if there's another bloom. Stop fertilizing the roses at the end of the summer, just before Labor Day.
Taking rose cuttings can lead to a new crop of beautiful, successful roses. Like many other plants, it's important to choose a sunny spot for your rose cuttings that has moist soil. Cutting strong, healthy stems right above a set of leaves makes for great growing conditions, and dipping your cutting in a rooting hormone will help the roots take faster. By keeping your rose cuttings well hydrated, you'll have strong roots in no time.
Pests and diseases: Prevention is the best way to avoid pest and disease problems. Start with disease-resistant varieties, keep plants in healthy condition (well fertilized and well watered), maintain good air circulation, keep foliage dry, and remove any diseased foliage or spent flowers. For Japanese beetle grubs, use beneficial nematodes or Milky Spore (Bacillus popilliae). Rose Rx is effective against scale, spidermites and aphids. For more information, see the Pest and Disease Finder.
When pruning, be judicious. If you prune too hard in autumn, plants can be damaged beyond recovery. Instead, wait until spring, when plants begin to leaf out for the new season. (Roses are often not the earliest plants in the garden to respond to spring’s warming temperatures, so be patient.) Give the plant time to show its leaf buds then prune above that level.
Be aware of your variety’s needs. Rose care will depend a lot on the variety you’re raising. Some roses like William Baffin and Lady Hillingdon climbing roses are more drought tolerant, for example, while others need more water. Some varieties can withstand less sunlight than others. Rose varieties should also be pruned differently depending on the variety and your climate area.
To plant in a garden, choose a spot with bright but indirect light, so cuttings won't be stressed by too much sun or heat. Northern and eastern exposures are perfect rooting spots. Cultivate the soil in your new propagation bed about 4 to 6 inches deep, so it crumbles easily. If your soil is heavy, incorporate a small amount of sand, so that new roots can penetrate without much effort.
To get the best success, yor rose seed will need a period of stratification (a cold period of about 6-12 weeks). Its a good idea to time this so that it coincides with when they would naturally start to grow in spring – probably around early March, depending on weather conditions. I would look to sowing them in late November/ December and popping them outdoors or if we have a mild winter then stick them in the fridge!
Prepare a pot. Fill the small pot with potting soil. For the best results, replace a quarter of the soil with perlite, peat moss, or vermiculite, or a combination thereof. This will increase air flow and draining, giving your cutting a better opportunity to root. If the soil is dry, water it and allow the excess water to drain out, so that the soil is evenly moist.
When you transplant your roses, be sure to dig a much bigger hole than you think you need (for most types, the planting hole should be about 15 to 18 inches wide), and add plenty of organic matter such as compost or aged manure. This will feed your plant in the years ahead. Some old-timers recommend placing a 4-inch square of gypsum wallboard and a 16-penny nail in the hole to provide calcium and iron, both appreciated by roses.
Some people don't bother to take the time to do this, but others do. While the rose seeds are soaking, you will see that some sink to the bottom and some float on the top. The seeds that float are sometimes not viable, so you might want to throw them away. The rose seeds that sink are said to be the good ones, and are the ones to plant. There are pros and cons to this theory, and many rose hybridizers simply plant all the rose seeds that are harvested.
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.