Allow rose hips to develop by leaving dead flowers on the plant. The flowers are typically pollinated by insects, or pollinate themselves in some varieties, so there is no need to pollinate by hand unless you are breeding specific plants together. Leave the flowers on the rose plant without cutting them. After they wither, small fruits known as rose hips will develop in their place.
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.
Water the planted rose seeds well and place them outside in direct sunlight (no need for Grow Lights). If there is still danger of frost, then you will need to place the seed trays in a protected location such as under a tree or patio. You will need to keep the rose seed trays watered and don't let them dry out. After about six weeks, or when the weather starts to warm up, the little rose seedlings will start to sprout. They will continue to sprout as long as the weather is cool, but will stop sprouting when it gets too hot.
Grow your roses indoors, alternatively. You can also raise roses in a greenhouse. You’ll need containers that are at least 9 inches (22.9 cm) wide. Spread 1 to 2 inches (2.5 to 5.1 cm) of small pebbles at the bottom of each pot to ensure good drainage and fill each with halfway with well-draining soil. Plant the roses just beyond the graft point and then water well.
Prepare a large hole. You'll need one for each rose bush you're planting. Use a garden spade or shovel to dig a hole 18 inches (45.7 cm) wide and 18 inches (45.7 cm) deep. The measurements don't have to be exact, but a hole this wide and deep will be suitable for most roses. Mix the soil you removed from the hole with compost, and use some of it to form a small mound in the base of the hole. Add some bonemeal or rose fertilizer.
Fertilizer: Roses are heavy feeders, and will benefit from a steady supply of nitrogen, phosphorus and potassium. You can provide these nutrients with either liquid or granular fertilizers, at a ratio of approximately 5-8-5. In most cases, regular applications of compost, rotted manure, fish emulsion and seaweed extracts will provide roses with all the nutrients they need. These organic amendments also help to moderate pH imbalances and stimulate beneficial soil life. Other organic amendments favored by rose growers include greensand, black rock phosphate and alfalfa meal.
The Misting Method: As you get more sophisticated in your rose propagating methods you may eventually want to set up a misting bench. It can be an open-air bench or one enclosed in a greenhouse, or even a small misting box, similar to the one my husband Bob built for me. (Refer to "How We Made Our Misting Box," from Rose Ecstasy. You could choose to rig it up with a manual or an automatically-timed mister, whatever your time, money, or expertise will allow. I am fortunate to have a very handy guy for a husband, who is a good sport whenever I come up with these crazy project ideas.
This is a fungus called black spot. Left untreated, it can cause all the leaves on your roses to turn yellow and fall off. It will also affect nearby plants, as it spreads by spores. Remove ALL INFECTED material and throw it away or burn it. Do NOT leave it on the ground as this fungus is very hardy. It can survive winter and travels very easily, even after being removed from the affected plant. Spray your plants regularly (bi-weekly) in the growing season with a good fungicide (I like the Bayer products). You can also add a little bit of dish soap and baking soda to a spray bottle with water and spray the entire plant.