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.
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!
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.
After the rose seeds have soaked overnight, rinse them in a strainer and place them into the blender with at least a cup of plain purified water (making sure all seeds are covered), and turn it on for a few minutes. It usually doesn't chop up the seeds, but rather, it will clean off the pulp remaining from the rose hip, which would otherwise mold if left on the rose seed. You may see a few seeds chopped up, but those usually aren't viable anyway. Flush the rose seeds again through a strainer using fresh purified water.
I planted mine in to the ground just like a normal rose bush, amending the soil with rose fertilizer and alfalfa meal. It is gorgeous, but because it's low to the ground, you should make sure to use drip irrigation or a soaker hose to water it so it doesn’t get black spots from the water splashing on the leaves. If yours is in a pot, let it go dormant in the garage or close to your home to keep the pot from freezing. Keep it watered and in the spring it should come back with more fertilizer to keep it happy.
Alfalfa provides solid nutrition to roses, supplying nitrogen, calcium, iron, phosphorus, and other nutrients, including a fatty acid known to promote plant growth. Work alfalfa meal or pellets into soil around roses (1 cup per large bush; one-half cup for miniature roses). You can also brew alfalfa tea by soaking alfalfa meal or pellets in water. Discover tips on making and using alfalfa tea from the American Rose Society.