Growing roses from seed can be difficult and requires patience!
Start your seeds by stratifying them - exposing the seeds to temperatures of about 35-40ºF for a long period of time. The easiest way to do this is in the refrigerator. Use a large freezer bag (1 gallon bag will fill a 10x10 tray), and fill it a little over halfway with moist - not soggy - soil. Make sure that the moisture in the soil is evenly distributed and add the seeds to the soil. Seal the bag with air, give it a good shake, and leave it in the fridge for 10-12 weeks.
Once the stratification period is complete, warm the seeds by placing the soil into a tray or containers on a heat mat. If your seeds were jumbled up, once they start sprouting, you can VERY gently adjust them around - just be sure not to touch their roots, or wait until they are larger to transplant them. Rose seeds can have a low germination percentage, but once warmed, should only take 2-3 weeks to sprout. When transplanting, use a spoon or small shovel to ensure the roots are undamaged.
Rose seedlings can be very fragile and are prone to disease. Do not over water, and keep water only to the base of the seedling. Over watering will lead to fungus, which can kill the seedling and spread to the other plants easily. Use a fungicide on rose seedlings to help prevent the development of disease. Use grow lights and have good separation and air flow around your seedlings, and they should grow well.
Roses from seed will spend the majority of their first year developing proper root structure. Once they are larger, at least 6-8”, they can be repotted as they grow. When growing from seed, be wary about planting directly. Most nursery roses are grafted onto a heartier root stock that can handle the environment. Plants started from seeds could be just as suited to your winters and summers, but need more time to settle, so if you do plan on planting outdoors, keep the roses potted for the first full year, and plant in early spring once all danger of hard freezes has past.
How to grow Roses from cuttings
Roses are easiest to propagate from cuttings. There are many methods available, such as the potato method, but the best method is straight into soil. Clean your shears with rubbing alcohol before and after use to prevent transfer between plants. Trim your rose cutting just above the cut tip, but not above the bottom set of leaves, then dip your cutting into rooting hormone powder. Tap off any excess powder. The bottom leaves can be trimmed at the stem.
If you are planting your cutting in a container, you’ll need to make sure that the soil stays moist. If the cutting dries out, it will not root. Use a container that is at least 6” deep. If planting outdoors, pick a sunny area. Poke a hole into your soil with a pencil that is about 3” deep and wide enough to not scrape off the rooting hormone powder.
Keep the roses well watered, but only water at the base of the plants. You may need to water several times a day, especially if it gets warm in your area. If you have a mini green house, this can help retain the moisture. You can also make your own with a plastic bag - just make sure that none of the plastic is touching the plant.
If the cuttings are kept moist, they should start to form roots within 3-4 weeks. If you give the cutting a gentle tug and feel resistance, roots have formed! Feed your roses with fertilizer to ensure their development and remove any spent blooms to promote new growth. Roses grown from cuttings will develop flowers faster than those grown from seeds, and you may get flowers in the first year.
How to Maintain Roses
Make sure to clean your tools before and after use, and make your cuts at 45º angles. Always cut back broken, dead, dying, or diseased branches. Also prune at the base to allow air to the base of the plant and to make it easier to water only at the base of the roses. Prune just before dormancy periods end, when the leaf buds begin to swell. Get your pruning done once the swelling starts but before they break open. If you wait too long, wait until after flowering to prune. A drip irrigation system will help prevent fungus. Keep thorns trimmed back to help you when working around the roses - if you have deer, consider leaving the thorns.