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.
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.
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.
The plant will become dormant—and you want it to stay that way; it is the natural state. After the first deep freeze, put is in a room or place (garage) with no heat and natural light (window). You can add some water occasionally but this is not intended to be “watering”; the plant is dormant and will not take it up but the soil can be lightly moist. Bring the plant back outside when it shows signs of coming back to life. Plant it, per the guidance above, when the soil warms.
Remove the seeds from the fridge. Try to do this around the time that the seeds would normally start to germinate, such as in early spring. Make sure that the environment outside of the fridge is about 70 degrees Fahrenheit. The seed will not sprout until you take them out of the fridge. Depending on the rose variety and individual seeds, the seeds could take anywhere from four to sixteen weeks to germinate. Often, 70% or more of the seeds never sprout at all.
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.
Despite their reputation for being finicky, most roses are simple to grow and easy to propagate at home. “Propagate" simply means to reproduce a plant easily from a simple cutting. Unlike seeds, which produce very different plants, rooted cuttings produce replicas of their parent. You don't have to be a trained rosarian to reproduce treasured family heirlooms or favorite garden roses.
There will be disappointments along the way, when many rose seeds fail to germinate, or perhaps they do germinate, only to die several weeks later from damp-off disease. Sometimes a rose seedling will turn out to be as ugly as sin, or very sickly, and you will reluctantly have to throw it away. Other times they will be just ho-hum, or look too much like its parent, and therefore have no value. But, just when you don't expect it, you might discover that one of your rose seedlings turns out to be very special.