For Southern California's Mild Coastal Zones
Bareroot planting season for roses extends from December through February.
It is best to plant new roses the same day as purchased. If that's not possible, soak bareroot plants overnight in a bucket of water. You can store roses this way for two or three days, but plant them as soon as is possible.
Select a site with as much sun as possible; six to eight hours is best, but a minimum of four hours a day will work. Also pick a site away from competing roots of trees and large shrubs.
Almost any soil will suit roses, but for best results, healthy plants, and optimum flower production, the addition of organic compost (planting mix) will both increase soil aeration and promote moisture retention.
For grafted and own-root grown roses, dig a hole about twice as wide and twice as deep as the plant's root system (approximately two feet by two feet and as deep should be adequate.
Mix a good grade of organic compost (planting mix) 50/50 with soil removed from hole. Build a cone of soil/compost mix and spread roots out evenly. Make sure that the bud union (grafted plants) or canes (own root plants) will rest on final soil level.
Backfill the planting hole with soil/compost mix, firming soil with your foot to make sure that there are no air pockets around the roots. Build a ring of soil around the hole to aid in watering.
Water the plant in well, soaking it several times. Check newly-planted roses for water at least once a week until established. Don't add fertilizer at planting time. Wait until roses starts growing and, when the new shoots are about three inches long (usually sometime in March), then apply fertilizer.
If the weather is hot and dry, cover the new canes with soil/compost mix to prevent them from drying out. Place a large brown paper grocery bag (with the bottom cut out) over the newly planted rose. Fill with moist soil or compost, and water well to give the new plant a chance to establish. Pull back the moist soil mix when new shoots start showing, usually around two weeks.
ENJOY THE ROSES!