Rosa

This excerpt is taken from the forthcoming book by Lane Greer and John Dole, Woody Cut Stems for Growers and Florists, published by Timber Press, www.timberpress.com, available January 2009.

Why You Should Grow It

Rose hips have become extremely popular with growers, since they extend the season, and with buyers, for their long vase life. Stems can be cut when fruits are green or red, with long or short stems. “Old rose” or “cabbage rose” flowers are in demand.

Why You Shouldn’t
    
Fruiting stems need to be defoliated. Thorns are nasty. Roses are attacked by numerous pests and diseases.

Species and Cultivars

For flowers: American growers cannot compete with the economies of scale present in countries such as Ecuador and Colombia for rose prices, and we are not encouraging anyone to grow the classic florists’ roses. Many of these cultivars are bred to open slowly and remain in the well-known vase shape and have limited fragrance. However, there is a demand for various types of garden and shrub roses. Of course, the queen of roses would have to be the hybrid teas, some of which are too similar to traditional cut roses to be commercially viable. Consider, instead, those cultivars with large fragrant flowers that open wide. While thousands of cultivars have been bred over the years, too many to list, most have rather low productivity compared to commercial cut flower types so on-farm testing will be needed. Very popular are “old roses”, also called garden roses or cabbage roses because of their numerous petals, and highly fragrant roses, which are generally unavailable through conventional channels.
David Austin roses, named for their developer, are prized by rose growers around the world, for their cabbage look, good fragrance and disease resistance. Unfortunately, they have poor vase life (2 to 3 days is typical) and weak necks, according to Washington grower Erin Benzakein and Idaho grower Ralph Thurston. This does not stop florists and designers from using them, primarily for events where vase life is not important. The following list of cultivars, both good and bad, was developed by Erin and Ralph. Keep in mind that no David Austin rose tested thus far has had more than a 4 day vase life.
·    ‘Abraham Darby’: Pink apricot, fragrant, falls apart minutes after being cut.
·    ‘Charles Darwin’: Pale yellow, 4 days maximum vase life.
·    ‘Dark Lady’: Stunning pink-red, 4 days maximum vase life.
·    ‘Fair Bianca’: White, holds petals well.
·    ‘Falstaff’: Dark purplish-red, good petal count, 4 days maximum vase life.
·    ‘Geoff Hamilton’: Soft pink, holds petals well.
·    ‘Gertrude Jekyll’: Dark pink, holds petals well.
·    ‘Golden Celebration’: Apricot-gold-yellow, falls apart quickly.
·    ‘Hyde Hall’: Good pink, light fragrance, numerous petals, many thorns, 4 days maximum vase life.
·    ‘Molineux’: Glowing yellow, holds petals well.
·    ‘Pat Austin’: Deep peach or orange, good fragrance, falls apart quickly, 3 days maximum vase life.
·    ‘Sweet Juliet’: Soft pink-peach, good for cutting.
·    ‘The Pilgrim’: Holds petals well, good shape. “Vase life fairly good for an Austin”.
Update: David Austin has developed a new line called ‘English Cut Roses’. In bud they look like hybrid teas, but they open to resemble old roses with many cupped petals, like other David Austin roses. Reportedly, they have a 9 to 10 day vase life. Cultivar names are ‘Cymbeline’, ’Juliet’, ‘Miranda’, ‘Patience’, ‘Phoebe’, and ‘Rosalind’. As of September 2008, they are available only on a very limited basis.
    
Dr. Laurie Hodges from the University of Nebraska-Lincoln warns: “Be aware that descriptions for the size of David Austin roses are based on the size grown under conditions in England, not the United States. Generally, for us the plants are taller. ‘Evelyn’ is listed as [growing to] 4 feet (1.2 m); it is more than 8 feet (2.4 m) in Lincoln. The color and fragrance are great but the neck is weak. ‘Heritage’ has similar color and fragrance, and a weak neck. It is listed as growing to 3 feet (1 m) but is pushing 7 feet (2.1 m) here. ‘Braithwaite’ is very floriferous for me with strong fragrance but extremely thorny; 3 to 4 feet (1 to 1.2 m) here.”

Kordes Cutting Garden™ hybrid teas: The German rose company Kordes has developed many cultivars for outdoor cut flower production. These have great vase life but not the cabbage look. Ralph Thurston (2007) states that Kordes roses last 8 to12 days for spray types, and 8 to 14 days for single-flowered types. If cut when the sepals are more than 60 degrees open, expect 7 days. We mention a few here that have been trialed by growers in different parts of the country.

·    ‘Caramel Antike’ (‘Antique Caramel’): Buff to apricot with peach-pink center, many petals, looks like an old garden rose, lightly scented, long-lasting. The #1 seller in Germany.
·    ‘Cinderella’: Light pink, light fragrance, few thorns, hybrid tea look.
·    ‘Ice Girl’: White, very fragrant, very productive but bruises easily, hybrid tea look.
·    ‘Magma’: Yellow with peach-orange-red edges.
·    ‘Fantasia Mondiale’, ‘Masquerade’ and ‘Pinguin’ held up well in the heat and humidity of Mississippi summers (Benzakein, 2006).
There are many more roses that have potential as cut stems. The very old cultivar ‘Cecile Brunner’, for instance, has good fragrance and good vase life with an old rose look. Try several types for more variety.

For hips: Many roses can be grown for their hips. The traits to look for include long, upright, thornless stems; annual fruiting; good color and fruit retention; and disease resistance (Bent, 2004).

·    ‘Amazing Fantasy’: Orange red hips, turning to bright red. Available from Kolster.
·    ‘Autumn’s Pride’: Red hips from late summer to winter. Available from Kolster.
·    ‘Cupid’: Large pear-shaped hips are yellow and orange. Plants grow 15 feet (4.5 m) tall. Hardy to Zone 6.
·    ‘Dortmund’: Large oval red or orange-red hips. Plants grow 6 feet (2 m) tall. Hardy to Zone 5. Available from Kordes.
·    Fair series: Includes ‘Fair Diamond’ (red, fewer thorns), ‘Fair Fall’ (orange-red), ‘Fair Orange’ (orange/green, oval), ‘Fair Pearl’ (purple and green), ‘Fair Pink’ (pink) and ‘Fair Red’ (red). Available from Bartels Stek.
·    ‘Forest Queen’: Small red hips.
·    Fruitilia series: Includes ‘Big Fruitilia’, ‘Coffee Fruitilia’, ‘Orange Fruitilia’ and ‘Red Fruitilia’. Available from Kordes.
·    ‘Giant Fantasy’: Very large, red hips, few or no thorns. Available from Kolster.
·    ‘Herbstfeur’ (‘Autumn Fire’): Large, pear-shaped red hips, large but few prickles. Plants grow 8 feet (2.4 m) tall. Hardy to Zone 6.
·    ‘Jewel’: Small red fruits. Available from Bartels Stek.
·    ‘Madame Gregoire Staechelin’: Pear-shaped hips are yellow-orange or orange-pink. Plants grow 13 feet (4 m) tall. Hardy to Zone 6.
·    ‘Magical Fantasy’: Deep red hips, harvest period is up to 3 weeks earlier than most cultivars. Available from Kolster.
·    ‘Magical Miracle’: Orange-green hips are oval, matures later in fall, smaller plants. Available from Kolster.
·    ‘Magical Mystery’: Green hips, matures later in fall, smaller plants. Available from Kolster.
·    ‘Magical Queen’: Large, green hips in mid- to late fall, small plants. Available from Kolster.
·    ‘Pumpkin’: Huge orange hips. Vigorous plants look like R. rugosa, growing 5 feet (1.5 m) tall. Very popular cultivar among growers. Available from Bartels Stek.
·    ‘Scharlachglut’ (‘Scarlet Fire’): Large hips are orange-red and urn-shaped, few large prickles, red flowers. Plants grow 9 feet (2.7 m) tall. Hardy to Zone 4.
·    ‘Sensational Fantasy’: Red hips, very few thorns, red branches, long production season. Available from Kolster.

Rosa canina: Dog rose or briar rose has elongated orange-red hips and is native to Europe, but wild-growing plants can be found in the eastern United States. The flowers are simple and pink. Plants have lots of prickles and grow 8 to 10 feet (2.4 to 3 m) tall. Hardy to Zone 5.
·  ‘Abbotswood’: Semi-double flowers.

Rosa glauca (which also includes R. rubrifolia): Red-leaved or blue-leaved roses have reddish-purple foliage, pink flowers, and bright red or dark red elliptical hips in clusters. Flowers are produced on old wood. Plants grow 6 to 7 feet (2 to 2.1 m) tall and are disease resistant. Hardy in Zones 2 to 8.

Rosa macrophylla: Known as big hip rose, there are two cultivars well-suited for production.
·    ‘Doncasteri’: Pink flowers are followed by very long, bottle-shaped bright red hips. Plants grow 7 feet (2.1 m) tall. Hardy to Zone 4.
·    ‘Master Hugh’: Bright red hips are huge. Pink flowers. Shrubs grow 15 feet (4.5 m) tall. Hardy to Zone 4.

Rosa moyesii: Moyes rose hips are large, shiny red and jug- or bottle-shaped. Plants bear red flowers in summer and have lots of prickles. Shrubs grow 8 to 12 feet (2.4 to 3.6 m) tall. Hardy to Zone 5.
·    ‘Geranium’: Hips are larger than the species.
·    ‘Highdownensis’: Orange hips, fast growth.
·    ‘Sealing Wax’: Red hips.

Rosa pimpinellifolia (which also includes R. spinosissima). Scotch or burnet rose has round, shiny reddish-black hips, white flowers and lots of prickles. Plants grow 3 feet (1 m) tall and sucker. Hardy to Zone 3.

Rosa roxburghii: Chestnut rose has large, spiny yellow hips that fall off as soon as they mature. Plants grow 6 feet (2 m) tall and wide. Hardy to Zone 6.

Rosa rubiginosa (which also includes R. eglanteria): Sweet briar rose has red or orange-red, hairy, oval hips. Pink flowers open in late spring. Plants have lots of prickles and grow 10 to 12 feet (3 to 3.6 m) tall. Cultivars include ‘Anne of Geierstein’ and ‘Meg Merrilies’. Hardy to Zone 5.

Rosa rugosa: Rugose rose is called “sea tomato” for its red, cherry tomato-sized fruits. Hips are produced early and flowers continue to open throughout the summer. Plants grow 4 to 5 feet (1.2 to 1.5 m) tall and sucker to the point of invasiveness. Hardy to Zone 5 and actually prefers cool climates.
·    ‘Scabrosa’: Hips are different colors, from green to tomato red.

Rosa sweginzowii: Red hips are long and bottle-shaped. Plants have pink flowers, long prickles and grow 9 feet (2.7 m) tall. Hardy to Zone 5.
· ‘Macrocarpa’: Larger hips.

Rosa villosa (which also includes R. pomifera): The apple rose has rich red, oval, bristly hips. Plants have pink flowers and grow 6 feet (2 m) tall. Hardy to Zone 5.

Rosa virginiana: Profuse numbers of round, red hips make Virginia rose a winner. They also have the best fall foliage display. Plants are easy to grow, reaching 5 feet (1.5 m) tall. Hardy to Zone 4.

Rosa webbiana: Orange or red hips are elongated and jug-shaped. Plants are 6 feet (2 m) tall. Hardy to Zone 5.

Production

General growth: Ideal growing conditions for roses include high light, warm days [75 to 90ºF (24 to 32ºC)], cool nights, [45 to 65ºF (7 to 18ºC)], excellent soil drainage, slightly acid to neutral soil, good air circulation, low humidity and limited rainfall during the growing season. Rarely do they receive this kind of growing environment.

Roses need full sun in most areas. If there is high light and high temperatures, quality may be improved by growing under shade cloth between 15 and 50%. Shade provides longer stems, larger flowers, less faded flowers, and large healthy leaves.
Some plants sucker, others do not. Some require staking, most do not. Use a complete fertilizer but not too much nitrogen. “Adding potassium shortly before harvest improves the quality of rose hips, and an application of copper strengthens the wood.” (Bent, 2004). Plants produce for 15 to 20 years.

Roses are often considered difficult to grow, but this need not be the case. In the southeastern United States, summer humidity causes diseases such as black spot to become very serious problems. The best antidote is prevention. Choose disease resistant cultivars that are suited to your growing environment. Consider growing roses for hips rather than flowers, since stems are defoliated before sale.

Spacing: Varies from 1 to 4 feet (30 to 120 cm), depending on the cultivar. Two to three feet (60 to 90 cm) is sufficient for most. With close spacing, yields per plant decline but overall yield per square foot increases. Close spacing also decreases air circulation around the plants.

Pruning: Pruning varies by location, species and stem length desired. Some growers prune plants in July to get fruits in September. Others cut longer, older stems and do not prune except to harvest. Ralph Thurston, who grows rose flowers, disbuds his plants during the first few months after transplanting to get stronger plants.

Pests and diseases: Roses suffer from numerous diseases and pests. Black spot is the most frequent problem, particularly for growers living where summers are humid. Powdery mildew, botrytis and rust are also common problems. All of these diseases are caused by fungi. A chemical or organic fungicide will need to be sprayed every 1 to 2 weeks, particularly in high humidity areas. The most prevalent insects are aphids, thrips and spider mites. Deer can also do a lot of damage – do not be fooled into thinking that the thorns will protect the plants.

Harvest and Postharvest

Stage of harvest: Harvest stage for flowers depends on the market. They can be cut when the sepals are at 60 degrees, or when the outer petals begin to open. Kordes recommends cutting stems down to the 2nd, 3rd or 4th node. Other recommendations are to cut stems back to the second 5-leaflet leaf above the previous cut. “During cooler weather the flower buds should be allowed to develop further prior to cutting” (Kordes, no date).
Hips can be harvested while green, just as they begin to color, or fully colored. If harvesting later, cut before the hips are overly mature or begin to shrivel. The Dutch company Kolster cuts all stems from the plant at one time (coppicing). Expect the first crop the second year after planting. Some growers cut one-year-old growth, others sell two-year-old stems. Cutting after a light frost or two will improve defoliation.

Expected yields: For flowers, young plants will yield about 10 stems each, depending on cultivar (Thurston, 2007). Established plants will yield 30 to 60 stems per year (Benzakein, 2006; Thurston, 2007). For hips, expect 20 long stems, or 0.8 to 2 lbs (400 to 900 g) per plant (Bent, 2004).

Conditioning: Use hydrator or preservative for flowers. Kordes recommends placing flowers into a hydrator (low pH) and holding at 35 to 39ºF (2 to 4ºC) for at least 6 hours.
No conditioning needed for hips. Dole and Possiel (2007) found that hydrator and preservative treatments did not extend vase life of rose hips. Leaves must be removed, either by hand or by sweating. At Kolster, they sweat stems for 2 days under white plastic, then pull off or shake off the remainder by hand. Most growers do not remove thorns.

Storage and shipping: The heads of florists’ roses are wrapped in plastic or cellophane. Buds continue to grow while being shipped.  Hips can be held in the cooler in water for weeks. For long-term storage, treat with a biocide immediately after harvest. Hips do not need a cold chain during transport.

Vase life: 2 to 3 weeks for hips. Dole and Possiel (2007) found that hips of unspecified Kolster cultivars had a minimum vase life of 16 days, averaging 24 to 26 days.


Propagation

Take cuttings during late fall and winter. Rooting hormone is beneficial but not necessary. Keep the humidity high with mist or a propagation tent.

Marketing

Florists’ roses are sold in groups of 12 or 25. Although this does not often apply to small-scale growers, standard rose lengths as determined by the industry are:
    Short             10-14 inches (25-35 cm)
    Medium            14-18 inches (35-45 cm)
    Long            18-22 inches (45-55 cm)
    Extra long            22-26 inches (55-65 cm)
    Fancy            26-30 inches (65-75 cm)
    Extra fancy            30 inches (75 cm) or more

Florists are looking for stems with numerous, small red hips, or for medium-sized elongated or elliptical fruit. Stems of hips are most often sold by length, in bunches of 10 or more. Cut stems may also be sold by weight in 1 pound (0.5 kg) bunches (Unione Cooperativa Floricoltori della Riviera, 1997).  According to several growers, sales potential is high, both for hips and for cabbage roses. Sales of hips are highest in fall.
    
Troubleshooting

Spotted foliage: Black spot is a way of life for rose growers. Institute a regular fungicidal spray program. Spots cannot be “cured” once they appear on the foliage, so begin spraying early.
Poor vase life of flowers: Many fragrant roses have poor vase life. Be sure to hydrate them adequately and limit their storage.
Wilted or shriveled hips: Late harvests, or harvesting after a severe freeze, will cause shriveled hips. There is a market for these, although unhealthy or black stems are not sellable.
Dead plants: Many roses are grafted, which increases their susceptibility to winter cold. Make sure plants are well hydrated after planting and healthy in fall. Mulch plants heavily in winter.

Uses

Cabbage roses can be used with just about anything. Mix them with lilies (Lilium), orchids and clematis (Clematis) seedheads. Even if only a few roses are used in a large arrangement with many other flowers, customers will notice and sniff the roses for fragrance.

Create an all-red arrangement with rose hips, red dahlias (Dahlia), fall foliage of oakleaf hydrangea (Hydrangea quercifolia), smoketree (Cotinus) foliage, and cotoneaster (Cotoneaster) fruit. Hips are often sold preserved or used fresh in wreaths.

Other Comments

Although it has small, glossy red hips, Rosa multiflora (multiflora rose) is listed as a noxious weed in numerous states and should not be grown. Rosa rugosa is listed as potentially invasive, but is not (yet) banned, in Connecticut.