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.
The next step how to grow roses from seed is to sprout the rose seeds. After having gone through their “stratification” time, take the containers out of the refrigerator and into a warm environment of around 70 F. (21 C.). I do my best to time this for early spring when the seedlings would normally be coming out of their cold cycle (stratification) outside and starting to sprout.
Once you have had several weeks of below-freezing temperatures, cover the base of the rose with 12 inches of soil or mulch, and then cover the canes with straw, leaves, pine boughs or even foam insulation. Climbing roses can be wrapped right on their supports, or you can lay them on the ground and cover the canes with straw or brush. In severely cold climates, hybrid teas are sometimes partially dug up, laid down onto the soil, and the entire plant is then covered with more soil or mulch.
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.
Prune the roses. Pruning roses keeps them both beautiful and healthy. The goal is to clear away crowded areas to open up the bush, which helps prevent rotting and disease. The pruning strategy differs according to the season, but the cut you make is always the same: prune just above a bud eyes, the areas where branches form. They look like small circular swells and are usually located above a set of mature leaves. Make a down-slanted cut on an outward-facing bud eye.
Northern gardeners need to know exactly what zone a rose is hardy to. Southern gardeners must also watch to see what zones are recommended for each particular variety, as some roses perform very poorly in hot and/or humid weather. Read the catalogs carefully and, if possible, purchase your roses from a local or regional grower. They will be able to advise you from experience about how a particular variety will perform in your area.
Most softwood rose cuttings will root within 10 to 14 days.1 To test their progress, tug very gently on the cuttings. You'll feel a slight resistance as the new roots form and grow into the soil. A gentle fish- or kelp-based fertilizer during this time provides beneficial nutrients. Once roots are established and plants show strong new growth, you can transplant your new roses to more permanent garden homes.
To start rose bush from cuttings, once the rose cuttings have been taken and brought to the planting site, take out a single cutting and remove the lower leaves only. Make a small slit with a sharp knife on one or two sides of the lower portion of the cutting, not a deep cut but just enough to penetrate the outer layer of the cutting. Dip the lower portion of the cutting into a rooting hormone powder.
Rose propagating methods have changed over the years, from the simple own-root varieties of the Victorian era, and progressing to the budded hybrids of the 20th century with its many options of exotic understock such as Rosa multiflora, Dr. Huey, Manettii, and Fortuniana. Now, rumor has it that many of the modern hybridizers and commercial growers are interested in returning to the simplicity of yore. Today's commercial rose growers are finding that budded roses are just too labor-intensive and expensive to produce. Because of this, it appears that we can look forward to more own-root roses being introduced and sold at our local nurseries in the future. Own-root roses will eliminate suckering and hopefully will eventually help to eradicate mosaic virus.
You must monitor the seedlings as they grow in their new pots for colour, form, bush size, branching, and disease resistance. Roses with weak, unhealthy or unattractive flowers can be discarded. It will take your new seedlings at least three years before they reach maturity and develop into a big bush. However, the first flower can be seen after one or two years.
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.
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.