While scanning the proceedings of a recent horticultural conference, I came across an interesting paper written by John Karlick, a University of California Farm Advisor in Kern County. John works closely with the rose industry in the Southern San Joaquin Valley, so has much experience with that favorite of all garden flowers. Below is a synopsis of John's paper.

The word "rose" evokes a range of thoughts and feelings. Indeed, roses have been used in landscapes since antiquity. The legends of Persia and India mention these plants, and they appear on some coins of ancient Rhodes. The Romans made the rose a part of pageantry, perfumes and parties. On one occasion petals were so deep some guests suffocated, probably after drinking too much rose wine.

Roses are the most popular woody shrubs in home gardens and landscapes. They offer a wide range of colors, plant forms, and can contribute flowers throughout the growing season. However, landscape managers may have reservations about using these plants more widely because of an assumed need for regular attention and pest control. Roses have an undeserved reputation for being temperamental, difficult to grow and prone to many diseases and insect problems. It is true that skill is required in the greenhouse to produce the perfect flower we see at a florist shop. However, we must remember that roses of various species are native to the Middle East, Far East and to parts of the United States. They survive and thrive in unattended natural settings.

Production conditions themselves recommends roses for average to difficult landscape situations. Most rose plants grown in the United States originate in the Wasco, California area. The plants grow in full sun, with daily maximum temperatures of 100 degrees F or greater for much of the growing season. Irrigation occurs no more frequently than at 10 day intervals. Plants in the field are vigorous, and many varieties reach heights of 4 to 5 feet six months after budding.

Most hybrid teas and grandifloras were developed primarily for large, showy flowers. However, with time, the rose varieties which have proved less popular have been withdrawn from the market. Older durable plants, no longer under patent, continue to be produced. These include 'Mister Lincoln', 'Double Delight', and 'Peace'. For low maintenance situations, variety resistance to mildew and blackspot should be considered. Because of their profuse bloom and disease resistance, floribundas and polyanthas are, as a group, more suitable for landscape use than teas and grandifloras. Heaviest bloom occurs twice per season, spring and fall, but many flower all season. Glossy foliaged varieties often have good resistance to mildew.

Cultural practices are greatly simplified with landscape varieties. Planting is easier because thorns are small and infrequent. Petals abscise cleanly, so deadheading is not required. Plants may be used as informal accents, mass color plantings, hedges, or can be shaped. Varieties have been selected for attractive habit. Planting sites may have full sun to semi-shade, but roses do best with four or more hours of sun. Annual or biennial pruning to maintain size and renew vigor is the extent of pruning required. Because the internodes are closely spaced and the wood is medium to fine textured, pruning is simplified. A hedge shear or mechanical pruner may be used on most varieties. Spacing in the landscape will depend on mature size, but groundcover varieties can be planted 4 to 6 feet on center, and hedge varieties 4 to 6 feet apart.

Because landscape varieties grow on their own roots (not budded onto rootstocks), they can resprout from the ground true to variety if the tops are killed. There are selections available especially bred for cold hardiness, with the added benefit that cold hardy varieties often have outstanding disease resistance.