Please keep in mind that many rose bushes are grafted rose bushes. This means that the bottom part is a hardier rootstock that will withstand cold and heat better than the top and more desired part of the rose bush. Starting a rose bush from cuttings places the new rose bush on its own roots, so it may not be as hardy in cold climates or in extreme heat conditions climates. Being on its own root system can cause the new rose bush to be far less hardy than its mother rose bush.
I would definitely mix in some compost with your garden soil as this will improve the structure of it. The dusting with fungicide is useful as it prevents the risk of infection, however, if you keep an eye on them and be ready to spring into action then it could be worth trying without . As for planting, I would personally keep them inside for a while, give them a chance to strengthen up before putting them outside in the elements!
Why choose an old-fashioned rose over a modern hybrid? Many of the old rose varieties offer more fragrance, more complex and interesting blooms, greater disease resistance, easier care and more interesting forms. But modern roses can offer all-season blooms, and a much broader range of colors and flower forms. Some are also far more cold- hardy and disease-resistant than any of the old-fashioned varieties.
Some roses root easier than others — old-fashioned heirloom types often root better than modern hybrids — but don't let that keep you from trying your hand at replicating garden favorites and sharing your love of roses and gardening with family and friends. RootBoost™ and GardenTech® brands are here to help you learn and succeed in all your gardening projects, so you can experience all the joys of gardening.
Plant the seeds. Some store-bought seeds can be planted immediately. If you germinated your own seeds as described above, plant them as soon as they begin to sprout. Plant with the sprout pointed downward, as this is the root. Lightly cover them with soil, about 1/4 inch (6 mm) deep. Space seeds at least 2 inches (5 cm) apart to minimize competition.
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.