One of the best ways to propagate roses is by transplanting them in their bare root state. Bare-root roses remain stagnant until they are "awakened" through soaking and planting on the ground or in containers. Here are the simple steps to plant bare-root roses in containers.
Purchase the best bare-root roses you can afford. Grade #1 stock, which is more mature and hardier than Grades 1 1/2 and 2, has the highest rate of success.
Tag the bare-root roses when you unpack them. This will help you identify the plant before it blooms and when you propagate them later on. Cut up some hard plastic packaging material and punch a hole at one end; use a permanent marker to scribble the rose's name; then attach the tag to the plant loosely with a twist tie.
Soak the bare-root roses in a bucket of water for 10 to 24 hours.
Prepare your containers. Black plastic pots are preferred because they retain heat and moisture better than clay pots. For medium to large bare-root plants, use an 8-inch or 12-inch pot. Mix three parts potting soil and one part perlite for good drainage. Fill the pot halfway with the potting soil mix, forming a mound in the center to support the plant and allow maximum contact of soil and roots.
Trim off any decaying or broken roots to promote root health.
Rest the plant on the soil mound, spreading the roots outward.
Fill the pot with soil while holding the bare-root plant steady. The soil level should be just above the bud union (also called graft union) where the climate is generally cold, and just below the bud union where the climate is moderate to warm. Press the soil firmly and water the pot thoroughly.
Prune an inch or two from the branches (also called canes) to leave about 6 to 8 inches, which is the ideal length for healthy start-up shoots.
Set the pots in a bright but shaded area for about a week to minimize shock and help the plant to stabilize. When leaf sprouts have grown to about 2 inches, move the pots to a sunny location where they will receive six to seven hours of sunlight per day.
Most potting mixes are already treated with sufficient fertilizer for the bare-root plant's initial growth. Some experts suggest supplementing the potting soil with compost, bonemeal, superphosphate or commercially available rose fertilizers. Add organic mulch like bark or pine needles over the soil to discourage weeds, control moisture and keep the soil warm. Leave a little space between the mulch and the rose stem to prevent rotting.
Place your rose containers only in areas where they will receive not just sufficient sunlight, but good ventilation as well. Poor air circulation can encourage molds and moisture-loving pests.