ROSES IN THE GARDEN AND LANDSCAPE:
CULTURAL PRACTICES AND WEED CONTROL
Integrated Pest Management for Home Gardeners and Landscape Professionals
Roses in the landscape grow within an made them a welcome and colorful upright plants, mounding shrub roses,
interrelated system that includes other addition to the landscape. and ground covers:
plants, environmental conditions, pests, " Upright plants grow as
and other organisms. Through careful Modern garden roses may be classified medium-to-large
selection of plant varieties and manage- into several categories based on lineage shrubs with uniform
ment of environmental conditions with and flowering characteristics. Most foliage and bloom.
proper cultural practices, beautiful hybrid teas and grandifloras were de- These varieties can
roses can be grown with a minimum of veloped primarily for their large, be used as border
pest problems. Initial placement of showy flowers and differ greatly from plantings, screens,
roses into a suitable site gives plants the each other in their disease susceptibil- or for vertical ac-
best opportunity for growth with mini- ity. Because of their profuse bloom and cents in a landscape
mal maintenance. Once established, disease resistance, the cluster-flowered design. Multiple
healthy roses provided with appropri- floribundas and low-growing polyan- plantings can be
ate fertilizer and irrigation are less sus- thas are more suitable for landscape use maintained as an
Polyantha rose
ceptible to some pest problems. than hybrid teas and grandifloras. informal hedge.
Sanitation efforts such as picking up Varieties include  Sevillana,  Pink
fallen leaves and winter prunings can A relatively recent occurrence in rose Meidiland, and  Simplicity.
contribute to reducing disease and in- breeding has been the development of " Mounding shrub roses are more ram-
sect incidence in spring. Finally, weeds landscape roses, also called shrub roses, bling than upright varieties. Uses
must be managed to reduce competi- which are cultivars selected specifically include borders and mass plantings.
tion and provide an attractive land- for use as flowering shrubs in the land- Varieties include  Bonica,
scape. For details on insect and mite scape. These varieties have enhanced  Flutterbye,  Lady of the Dawn,
pests and their management, see Pest disease and insect resistance and re-  Lavender Dream, and  Scarlet
Notes: Roses in the Garden and Landscape quire less pruning than the traditional Meidiland.
Insect and Mite Pests and Beneficials. To garden varieties of roses. Planting is " Ground covers are low-growing variet-
find out more about diseases of roses easier because thorns are smaller and ies that are useful as covers for slop-
and how to prevent them, see Pest less numerous than those on other vari- ing banks, borders for walkways, or
Notes: Roses in the Garden and Landscape eties. Because petals cascades over walls. Some varieties
Diseases and Abiotic Disorders. Both pub- separate cleanly from reach 21D 2 feet in height. Varieties
lications are listed in References. the stem, deadheading include  Alba Meidiland,  Baby Blan-
(the removal of old ket,  Carefree Delight,  Eyeopener,
flowers) is not re-  The Fairy,  Flower Carpet,  Ralph s
CULTIVAR SELECTION
quired. In cold Creeper,  Red Ribbons,  Red
Perhaps the earliest specific use of roses weather areas, the Meidiland, and  Sea Foam.
as landscape plants in the United States own-root propagation
occurred in the late 1800s and early of landscape roses
CULTURAL PRACTICES
1900s. Hybrids of Rosa rugosa roses means plants can regen-
from China and Japan were extensively erate true-to-type even if
Establishment
planted as hedges and snowbreaks killed to the ground by
Roses are often purchased in late winter
around farmsteads on the Great Plains. cold temperatures.
or early spring as bare-root plants. To
Although the flowers of R. rugosa culti- Landscape roses are
maintain plant health, these plants
vars are small, the ability of plants to available in three
should be held in the nursery under
survive, even in temperatures of -30°F, growth forms: Grandiflora rose
Publication 7465
PEST NOTES
University of California
Agriculture and Natural Resources
Revised July 2003
July 2003 Roses: Cultural Practices and Weed Control
cool conditions with their roots kept warmest months. Mulches help to de-
Table 1. Suggested Soil pH, ECe, and
moist. Packaged plants should also be crease water loss from the soil through
Nutrient Levels for Growing Roses.
kept cool because warm temperatures evaporation and may enhance growth
hasten loss of carbohydrate reserves of the root system. Soil characteristics Unit Low High
and contribute to gradual desiccation
pH (acidity/alkalinity)  6.0 7.5
Soil and Nutritional Requirements
of wood and the resulting difficulty in
ECe (electrical conductivity) dS/m 0.5 2.0
establishment. As day temperatures rise Roses prefer well-drained soil with a
NO3-N (nitrate-N) ppm 35 150
above 70°F in late spring, establishment pH near the neutral value of 7.0. Many
NH4-N (ammoniacal-N) ppm 0 20
from bare-root stock becomes more diffi- California soils are still suitable despite
cult. To increase the percentage of sur- a pH above 7.0, but the likelihood of
P (phosphorus) ppm 5 50
vival when planting bare-root stock in micronutrient deficiencies becomes
K (potassium) ppm 50 300
May or June, mist the wood once or greater as pH increases, especially for
Ca (calcium) ppm 40 200
twice per day and place mulch around pH values above 7.5. Roses are not salt
Mg (magnesium) ppm 20 100
the base of the plant to increase tolerant, so electrical conductivity (EC )
e
B (boron) ppm 0.1 0.75
humidity. values, which measure the level of salt
Fe (iron) ppm 0.3 3.0
ions in the soil, should be less than 2.0
Roses may be planted throughout the dS/m. Soil test results with levels suit- Mn (manganese) ppm 0.2 3.0
summer from nursery containers. How- able for roses are given in Table 1.
Cu (copper) ppm 0.001 0.5
ever, the current season s stock is more
Zn (zinc) ppm 0.03 3.0
vigorous than container stock held over Nitrogen is the nutrient typically in
Mo (molybdenum) ppm 0.01 0.10
from the previous year. With the excep- shortest supply. Although nitrate
tion of miniatures and smaller cultivars, (NO3-N) levels may be lower than the
roses generally do not perform well suggested value, this nutrient is easy to Table 2. Suggested Values for Nutrient
Levels in Rose Tissue.
when maintained in nursery pots for add so that a low supply of NO
3-N is
more than one season. usually not problematic. For landscape
Nutrient (unit) Low High
plantings or home gardens, adding
N (%) 3.0 5.0
Planting sites may have full sun to par- nitrogen in the form of soluble or slow-
P (%) 0.2 0.3
tial shade; however, roses do best with release fertilizer at the rate of 1 pound
K (%) 2.0 3.0
6 hours or more of direct sun. actual nitrogen per 1,000 square feet
Ca (%) 1.0 1.5
twice per year, spring and fall, should
Irrigation Mg (%) 0.25 0.35
provide an adequate amount of this
Zn (ppm) 15 50
Roses need to be irrigated in most loca- nutrient.
tions in California. Drought stress leads
Mn (ppm) 30 250
to defoliation and sunburn of canes and Tissue tests may be used to provide
Fe (ppm) 50 150
may contribute to spider mite prob- information on the current nutritional
Cu (ppm) 5 15
lems. However, overwatering or poorly status of the rose plant. Suggested nu-
B (ppm) 30 60
drained soils may lead to root disease trient levels are presented in Table 2.
and nutritional deficiencies. Water may
Pruning
be supplied via overhead sprays, flood
irrigation, or drip tubing. Irrigation Pruning provides an opportunity to winter before buds swell, although it
with over-the-top delivery should take direct growth and invigorate rose may be delayed where
place in the morning so foliage dries plants. Pruning requirements vary late spring frosts are
during the day. Frequency and dura- among types of rose plants. Hybrid common. A starting
tion of irrigation will depend on teas, grandifloras, and many floribun- point in pruning is to
weather conditions and soil texture. das benefit from annual pruning in remove diseased and
Checking after irrigation to determine which three to five canes remain in a damaged wood. Between
soil moisture status and rate of deple- vase-shaped configuration. Landscape one-third and two-thirds
tion is helpful in scheduling irrigation. varieties may be hedged or left of healthy wood may be
Roses do best when 50% of available unpruned, although removed through a com-
water is depleted between irrigations. rejuvenation pruning bination of heading and
Pruning cut
Daily irrigation should not be necessary or removal of older thinning cuts, which
even in the desert areas of California. stems every 2 to 3 should be within 1D 4 inch above
For example, in the Central Valley, years will renew outwardly growing lateral buds or
irrigation twice per week is usually vigor in the plant- branches. Removal of more wood re-
satisfactory for roses in landscapes; rose ing. In most of Cali- sults in fewer but larger flowers with
plants in production fields are irrigated, fornia, pruning longer stems; less pruning preserves the
Vase-shaped
at most, at 8-day intervals during the should be done in size of plants and results in a greater
configuration
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July 2003 Roses: Cultural Practices and Weed Control
number of smaller flowers. Pruning In extensive plantings or professionally stems in addition to the leaves. Glypho-
paint or other wound dressings are not managed public or commercial land- sate damage may appear at bud break
necessary. scapes, mulches and hand-weeding the following spring after a summer or
may be supplemented with herbicides. fall application that contacts leaves or
During the growing season, the rule-of- Some of these materials may be avail- stems; symptoms include a prolifera-
thumb for cutting blooms on first-year able only to professional applicators tion of small, whitish shoots and leaves.
plants is to make the cut above the first and not to home gardeners. The For more information on weed control
outwardly facing five-leaflet leaf. On preemergent herbicides oryzalin in the landscape, see Pest Notes: Weed
well-established plants, cut blooms (Surflan and Weed Stopper) and pen- Management in Landscapes in References.
somewhat lower to ensure new canes dimethalin (Pendulum) can be used
can support the weight of the blooms. around roses before weeds emerge or
REFERENCES
Cuts can be made above the first out- after weeds are removed, but before
wardly facing five-leaflet leaf up from others germinate. These herbicides will Flint, M. L., and J. Karlik. 1999. Pest
the base of the shoot. Removal of spent not control established weeds. While Notes: Roses in the Garden and Landscape
rose blossoms allows the plant to con- these herbicides primarily control Insect and Mite Pests and Beneficials. Oak-
serve energy and leads to further flower grasses, they also control broadleaf land: Univ. Calif. Agric. Nat. Res. Publ.
production. To deadhead a rose plant, plants such as chickweed, fiddleneck, 7466. Also available online at
use the same guidelines as those for knotweed, lambsquarters, pigweed, www.ipm.ucdavis.edu.
cutting blooms. Landscape varieties do prostrate spurge, oxalis (from seed),
not need to be deadheaded. and purslane. The postemergent herbi- Karlik, J. 1998. Weed management for
cides fluazifop-p-butyl (Fusilade), roses in landscape plantings. Proc. 50th
sethoxydim (Grass Getter), and Annual Calif. Weed Sci. Soc., pp. 12-14.
WEED MANAGEMENT
clethodim (Envoy), which are used to
Weeds are common in many landscape control grasses, should be used when Karlik, J., and M. L. Flint. 1999. Pest
situations including around rose plant- the grass plants are small and will not Notes: Roses in the Garden and Landscape
ings. Mulching with 2 to 4 inches of injure rose plants. Direct these sprays to Diseases and Abiotic Disorders. Oakland:
organic material such as wood chips the base of the weeds for best control. Univ. Calif. Agric. Nat. Res. Publ. 7463.
will help reduce annual weeds and Be sure to consult labels for permitted Also available online at
make hand-weeding easier. Woven sites and rates. www.ipm.ucdavis.edu.
landscape fabrics placed under organic
mulch will provide weed control for Roses are sensitive to postemergent, Karlik, J., and C. Harwood. 1991. Land-
several years. In most home gardens, broadleaf herbicides used in the land- scape roses bred for performance. Calif.
mulches supplemented with regular scape such as 2,4-D, triclopyr, and di- Landscape Mag. 16(3):28-29.
hand-weeding or roguing (digging out camba. Use broadleaf herbicides with
the entire plant, roots and all) should great care when rose plants are present Wilen, C. A., and C. L. Elmore. 2001.
provide satisfactory weed control. Me- in the landscape so as to not cause dam- Pest Notes: Weed Management in Land-
chanical cultivation devices such as age from drift. Roses are also very sen- scapes. Oakland: Univ. Calif. Agric. Nat.
hoes must be used with care because sitive to glyphosate (Roundup), which Res. Publ. 7441. Also available online at
roses are shallow rooted. can be absorbed through the green www.ipm.ucdavis.edu.
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July 2003 Roses: Cultural Practices and Weed Control
For more information contact the University
of California Cooperative Extension or agri-
cultural commissioner s office in your coun-
ty. See your phone book for addresses and
phone numbers.
AUTHOR: J. F. Karlik
EDITOR: B. Ohlendorf
TECHNICAL EDITOR: M. L. Flint
DESIGN AND PRODUCTION: M. Brush
ILLUSTRATIONS: Karen Ling
Produced by IPM Education and Publica-
tions, UC Statewide IPM Program, Universi-
ty of California, Davis, CA 95616-8620
WARNING ON THE USE OF CHEMICALS
Pesticides are poisonous. Always read and carefully follow all precautions and safety recommendations
This Pest Note is available on the World
given on the container label. Store all chemicals in the original labeled containers in a locked cabinet or shed,
Wide Web (http://www.ipm.ucdavis.edu)
away from food or feeds, and out of the reach of children, unauthorized persons, pets, and livestock.
Confine chemicals to the property being treated. Avoid drift onto neighboring properties, especially
gardens containing fruits or vegetables ready to be picked.
Do not place containers containing pesticide in the trash nor pour pesticides down sink or toilet. Either
use the pesticide according to the label or take unwanted pesticides to a Household Hazardous Waste
Collection site. Contact your county agricultural commissioner for additional information on safe container
disposal and for the location of the Household Hazardous Waste Collection site nearest you. Dispose of
This publication has been anonymously peer
empty containers by following label directions. Never reuse or burn the containers or dispose of them in such
reviewed for technical accuracy by University of
a manner that they may contaminate water supplies or natural waterways.
California scientists and other qualified profes-
sionals. This review process was managed by the
The University of California prohibits discrimination against or harassment of any person employed by
ANR Associate Editor for Pest Management.
or seeking employment with the University on the basis of race, color, national origin, religion, sex,
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supported by the Extension Service, U.S. Department and Federal laws. Inquiries regarding the University s equal employment opportunity policies may be
of Agriculture, under special project Section 3(d), directed to the Affirmative Action/Staff Personnel Services Director, University of California, Agriculture
Integrated Pest Management. and Natural Resources, 300 Lakeside Drive, 6th Floor, Oakland, CA 94612-3550, [phone].
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