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Home , Agave, Agave americana, Aloe, Cactus, Dactylopius, Moneilema

COOPERATIVE E TENSION

Problems and Pests of , , and

AZ 1399 Revised 03/11 Table of Contents

Abiotic (non-living) problems...... 3 Selecting the correct and planting location...... 3 Freeze Damage...... 3 Sunburn...... 3 Planting depth...... 4 Poorly–drained soils...... 4 Irrigation...... 4 Hail damage...... 4 Diseases...... 4 Fungal diseases of pads and ...... 4 Phyllosticta pad spot ...... 4 Anthracnose of ...... 5 Other fungal lesions ...... 5 Fungal crown rot of ...... 5 Pythium rot of barrel cacti...... 5 and crown rot of agaves...... 6 Bacterial necrosis of ...... 6 Sammon’s virus of ...... 6 ...... 6 Agave Snout Weevil (Scyphophorus acupunctatus)...... 7 Cactus longhorn ( gigas)...... 7 scale ( )...... 7 Plant bugs...... 7 Coccid scale, soft scale ...... 8 Mites...... 8 ...... 8 For More Information...... 9

2 The University of Arizona Cooperative Extension Agaves, , cacti and are classified as succulents - paired; but unless the freeze that have highly specialized anatomical features such as is of particularly long dura- thick waxy cuticles, fleshy or minimal leaves, modified leaves tion or exceptionably cold, the (spines), and with extra storage capabilities for food and damage may be only cosmetic, water. These modifications allow them to survive and thrive and the plant will grow out of in harsh environments. They survive long periods of it. When exposed to a severe in areas of sparse rainfall and intense heat. During freeze, portions of columnar stressful periods many succulents cease to grow. They drop cacti will yellow, and then die unnecessary leaves, dehydrate and become dormant until completely (Fig. 2). In freeze- conditions for growth return. damaged barrel- cactus, Despite their adaptations succulents suffer from diseases, the margins of ribs become pests and cultural problems. Some of the more common straw yellow. If temperatures Fig. 2. Severe freeze damage to are not substantially below problems that occur in agave, aloes, cacti and yuccas in Ari- peruvianus. zona are discussed in this bulletin. freezing (a “hard freeze”) and the freeze lasts for only a few hours or less, only the epider- mis may be damaged, and the plant will outgrow the dam- Abiotic (non-living) problems age in several . Yuccas may be damaged by sub-freezing temperatures. The damage will appear similar to that of the Abiotic problems are not caused by living organisms. They freeze damaged agave in Fig. 1. When the freeze is of long include poorly drained soils, sun exposure, and weather duration, extreme, or the is not suited for the local cli- events such as cold and high temperatures, excessive rainfall, mate, damage may be severe. over watering, planting too deeply and hail damage. In trans- planted agaves, aloes, cacti and yuccas, abiotic problems are Freeze damage can be prevented. It is important to become probably the most common problems that growers and hom- acquainted with temperature requirements of the particu- eowners encounter. lar species. Protective measures often can be taken to assure survival. Cold-sensitive plants should be grown in areas that Selecting the correct plant and planting location receive radiated heat at night from a patio or wall or in hilly areas where air temperatures are slightly warmer. Careful selection of species that are suited to your local con- ditions is necessary and will eliminate or diminish serious Covering the plant with a cotton sheet will help on nights problems. Choose species that are found in your neighbor- that are just at or slightly below freezing. Another strategy hood or area. Visit specialty cactus and succulent nurseries is to place a 60-watt light bulb under the cotton sheet, taking and discuss cold hardiness, heat and cold tolerance, mature care that the light bulb does not touch the plant or the cotton size of the plant, growth rate and known problems of a specific sheet. Do not cover the plant with plastic sheeting. Plastic plant with the nursery personnel. Contact your local Coopera- is a poor insulator and will transfer the cold directly to the tive Extension office for expert advice. Visit local arboreta that plant wherever it touches the plant. Containerized plants can have extensive succulent collections. Choosing the right plant be moved indoors until freezing weather has passed. If kept for the right place is the first step in successfully growing these dry and placed in a brightly lighted area, they will survive unique plants. without damage. Most succulent species originate in areas of diverse . Extremely low temperatures may cause a loss of turgor in For example, many agaves grow in pine and oak forests, open . This causes sagging of (arms) or death grasslands and even in barren open areas. By researching a of the apical (growing tip) that results in saguaros little about your plants and their special requirements, they with many stems or ‘heads’. can be planted in areas of your yard that fulfill most of their requirements. Sunburn Freeze Damage Sunburn is a common problem in greenhouse or Many of the more showy and shade house grown plants. It exotic succulents originated in is also problematic in plants frost-free climates. As a result, grown in open beds or fil- when temperatures remain be- tered sunlight in nurseries low freezing for several hours, when these plants are trans- they suffer freeze damage. The planted into open landscapes. damage originally manifests it- Those parts of the plant that self as blackening of the exposed have not been acclimated to parts of the plant (Fig. 1). After Figure 3. Sunburn on golden barrel cactus. direct sun will burn easily. a few weeks, the blackened area Sunburned plants turn yel- Figure 1. Freeze damage on Agave. will dry out and become crisp. low. As the damage progresses, the epidermis turns straw Freeze damage cannot be re- yellow and dies. Barrel cacti and columnar cacti are very

The University of Arizona Cooperative Extension 3 susceptible to this kind of damage (Fig. 3). The entire plant Irrigation usually does not die, but it is permanently scarred. Similar One of the most serious abiotic problems is over-water- damage occurs on Y. aloifolia, Y. gloriosa, and Y. recurvifolia, es- ing. This combined with poorly drained soils is a recipe for pecially during summer months. The apex of the or the plant failure. Plants should dry moderately to thoroughly area where the leaf naturally curves will become yellow. In between irrigations depending on the plant type and spe- severe cases leaves may die, but if damage is not severe, they cies. Conversely, in times of drought or no for pro- may recover at cooler temperatures. longed periods, supplemental water will diminish prob- Sunburn can be minimized in nursery-grown plants by lems associated with heat and sun damage. As a general placing the plant in the same direction as it had been previ- rule, watering succulents in well drained soils on a 10 - 14 ously growing. Many nurseries will mark one side of the day interval is sufficient to insure plant health and growth plant so it can be transplanted in the same orientation. Placing during summer. On heavier soils such as clay soils the wa- shade cloth (30%) or cheese cloth over newly-acquired plants tering interval may be decreased. On sandy or very rapidly reduces sunburn. If possible, purchase locally grown plants draining soils the frequency will have to be increased. Check that have been grown in full sun or partial sun (depending on the root zone 2‒3 inches (5‒7.5 cm) below the surface. If the the species) and acclimated to sunlight. soil is even slightly damp, wait until it has dried to irrigate. Greenhouse-grown plants that will be planted in the open By regularly checking the root zone before watering, you garden can be acclimated by gradually moving them out into can get a good idea of your plants’ water needs. A thorough full sun over a period of weeks or planting in shade of a decid- irrigation followed by a 2-14 day dry period (no rain, no uous tree or . Planting in late winter when solar radia- supplemental water) will give the soil a chance to dry out tion is less intense and using inorganic mulch such as gravel completely which in turn will reduce the incidence of soil or decomposed granite around new plants also will reduce borne pathogens. As the daylight decreases in fall and win- sunburn. Application of a mulch about two to four inches (5 - ter, irrigation may be reduced. When nighttime tempera- 10 cm) deep will help retain soil moisture and reduce reflected tures drop below 60�F. (16˚C.), discontinue irrigation; when light and heat, but be sure the mulch does not cover the base nighttime temperatures are above 60˚F, water as described of the plant and create a moist environment for rot organisms. above. Most of these plants can survive on natural rainfall Many species will benefit from partial or dappled shade. By through late fall, winter and early spring. planting near a deciduous tree or shrub, the plant will be pro- Hail damage tected from the summer sun and winter freezes. In some areas of the Planting depth desert southwest, hail storms cause consider- Proper planting depth is essential for the survival of many able damage to young succulents. In columnar cacti such as saguaro, green stem aloe, cacti, agave or other tissue should not be below ground. This is commonly done succulents. Hail damage with Carnegiea gigantea (saguaro) and other columnar cacti and on barrel type cactus re- leads to poor establishment and death of the plant. Do not at- sults in wounds at the tempt to ‘match’ plant sizes so that all the plants are identical point of impact leaving in height by planting some deeper than others. Young prickly scars that can vary from pear (Opuntia spp.) should be planted deeply enough so that Fig. 4. Opuntia pads damaged on one side by very small spots to larger they remain upright after planting. This usually is ½ to ¾ of hail (L) and reverse side (R) undamaged. lesions. On Agave spe- the depth of the lowest pad. cies, leaves may be perforated by the impact of the hail. When hail storms are accompanied by strong winds, damage to the Poorly-drained soils plant may be on one side of the plant only (Fig. 4). This distri- All succulents require fast-draining soils. Special ‘cactus’ bution of damage is helpful in recognizing hail damage. mixes are available at many retail nurseries. These mixes are There is no protection from hail unless plants are covered formulated for potted plants. Poorly-drained soils will predis- before a hail storm begins. Small areas or a few specimens pose the plants to attack by soil-borne, root-rotting pathogens may be covered with a heavy blanket or tarp to minimize the that may result in the death of the plant. Careful irrigation damage. management is critical in growing cactus, agave, and yucca successfully in heavy clay soils. In outdoor landscapes, add- ing copious amounts (up to 25%) of will improve Diseases drainage and soil structure. Fungal diseases of pads and leaves Sandy soils should be avoided because they will drain very Phyllosticta pad spot rapidly and retain little water and nutrients. They should be Lesions on pads of prickly pear cacti (Opuntia species) may be amended with well-rotted compost or peat moss. Fresh or un- caused by several different pests or environmental conditions. composted manures should not be used as soil amendments However, the most common pad spot on the Engelmann’s because the high salt content found in manures is detrimental prickly pear in the desert of Arizona is caused by a species of to root development. the fungus Phyllosticta. The disease is found throughout the

4 The University of Arizona Cooperative Extension desert. Lesions are almost should be replaced with completely black because of more tolerant species of the presence of small black Agave or another type of reproductive structures plant. called pycnidia produced Fungal lesions also may on the surface of infected develop on barrel cacti plant tissue (Fig. 5). Spores (Fig. 8). These infections produced within these usually develop during reproductive structures spring and are more are easily disseminated by common on plants that wind-blown rain or dripping Figure 5. Phyllosticta pad spot on Opuntia. are shaded. Infections Figure 8. Fungal lesions on barrel cactus. water and infect new sites rarely kill the plant but on nearby pads. Pads on the lower part of plants are often most cause irreversible cosmetic damage. If cacti are planted in an heavily infected since the humidity is higher and moisture area that is routinely problematic, the plants should be moved often persists after rain. Once pads dry, the fungus becomes if possible. Heavily infected plants should be removed, inactive and the lesions may fall out. placed in plastic bags and disposed of in the trash to reduce Severely infected pads or entire plants should be removed the spread of the fungi to nearby susceptible plants. from landscapes to prevent spread of the fungus. No other Fungal crown rot of Echinocereus controls are recommended. Soft rot of several species Anthracnose of agaves of Echinocereus is caused by Another fungus, a a species of Helminthospori- species of Colletotrichum, um, a fungal pathogen that causes a disease known produces airborne spores as anthracnose. It can abundantly. These spores be a problem on agaves are easily disseminated in during moist conditions splashing water and wind- or occasionally when borne rain. They require agaves are grown in the free water for germination shade and overhead Figure 9. Crown rot of Echinocereus cactus causes and penetration into the irrigated. Infections cause dark sunken areas in which tissue has rotted. host. Most occurrences lesions on the leaves have been in plantings in Figure 6. The anthracnose fungus causes and/or crowns. When commercial nurseries on lesions on Agave leaves in which spores are produced during wet weather. the fungus is active, it Echinocereus species, but produces a to orange the fungus is found on pad spore mass within the lesions (Fig 6). The spores are distributed cacti occasionally. The by splashing water and windborne rain. Leaves with active first symptom of infection lesions should be removed. In areas where disease has is dark, sunken areas that occurred, overhead watering should be avoided. Application are soft and water soaked of such as thiophanate methyl during wet weather (Fig. 9). In Echinocereus, may prevent new infections, but efficacy of disease may begin any- treatments has not been established. Figure 10. Internal rot of Echinocereus cactus. where on the upper part of the cactus and causes an Other fungal lesions internal soft rot (Fig. 10). In pad cacti, sunken soft-rotted Stem and leaf lesions areas appear on the pad surface. on cacti and agaves have Water management is probably important for prevention been associated with of this disease, but to date no research has been done to de- other fungi as well. They termine the optimum conditions for disease development. usually occur during Applications of fungicides such as thiophanate-methyl may prolonged periods help prevent infection where disease has been problemat- of cool, wet weather. ic. Infected plants should be removed so that they are not There is a great deal of sources of spores that will infect nearby plants. variation in susceptibility among Agave species. For Pythium rot of barrel cacti Figure 7. Fungal lesions on example, severe lesions develop during cool moist weather conditions. An internal soft rot of barrel cacti is caused by species of have been observed on Pythium, a soil borne pathogen that is favored by moist con- Agave weberi while other species growing nearby are not ditions (Fig.11). Golden barrel ( grusonii) is com- affected (Fig. 7). Species that are susceptible to fungal lesions monly affected. Pythium sp. can cause root and/or crown

The University of Arizona Cooperative Extension 5 rot if plants are placed plant tissue for long pe- in the ground too deeply riods of time. The bacte- when transplanted or are rium is spread by insects wounded and then over- and in infested soils. watered. Infections take place at Barrel cacti should be wound sites on roots, planted so that the roots trunks and branches, es- are placed firmly in the pecially those made by soil but no soil is placed insects, weather-related around the base of the events, or rodents. Dead and dying plants serve as Figure 11. Internal rot of barrel cactus caused plant. Care should be tak- Figure 14. Bacterial necrosis of saguaro causes reservoirs of the bacterium by Pythium. en to avoid wounding the soft tissue to break down leaving only the and as sources of bacterial fleshy part of the barrel woody skeleton. when planting. Since the rot is internal, it is often too late to inoculum for new infec- treat cacti once disease is detected. Preventive treatments tions. In large natural stands where disease occurs, proximity of mefanoxam or phosphytyl-Al may be warranted in valu- of saguaros to dead and dying plants significantly influences able species, but the best prevention is proper planting and mortality. watering. If noticed in time, new infection sites can be treated when very small (less than two inches (5 cm) in diameter) by care- Root and crown rot of agaves fully removing the infected tissue, along with a small margin Several soil borne pathogens including a species of the of healthy tissue, using a clean sharp knife. Allow the wound bacterium Erwinia and the fungus Fusarium have been impli- to heal on its own. Older infection sites exuding dark liquid, cated in root and crown rots of agaves. Disease is usually in especially those at the base of the plant, are not treatable. concert with infestations by the agave weevil, and currently Plants with advancing decay should be removed to prevent it is thought that weevil feeding enables these pathogens infection of nearby saguaros and damage or injury of persons to enter and cause disease when they normally would not or property. All infested plant material should be completely be pathogenic on healthy plants. See the section on agave removed from the site and away from any other saguaros. weevil for more information on this insect vector. Other than preventing wounds in the plant, such as those caused by the Sammons’ virus of Opuntia agave weevil, there is no control for the bacterial and fungal Opuntia Sammons’ virus infections once the microbes have entered the plant. is common on Engelmann prickly pear (Opuntia en- Bacterial necrosis of saguaro glemannii). It causes light Bacterial necrosis of yellow rings with some saguaro is caused by the mosaic pattern in the bacterium Erwinia cactici- pads and is often called da. The initial symptom a ringspot virus (Fig. 15). is a small, light-colored The disease is more of a spot with a water-soaked curiosity than a problem margin on the surface of since infections do not the trunk or branches that Figure 15. Characteristic rings on Opunti pads cause noticeable harm to may easily go unnoticed. infected with Sammons’ virus. the plant. The only known The tissue under the in- native hosts are species of Opuntia. Opuntia Sammons’ virus fection site soon becomes has no known insect vector, but it is sap transmissible. It is Figure 12. Symptoms of bacterial necrosis of brown or almost black. a member of the Tobamovirus and is closely related to saguaro. As disease progresses, the viruses such as tobacco mosaic virus. It is typically spread tissue may crack and ex- by propagating cuttings from infected plants. Do not use in- ude a dark brown liquid fected plants as a source of propagation material. No controls (Fig. 12, Fig. 13). If decay are recommended. is slow, the tissue may not have the liquid exu- dates. As infected tissue Insects breaks down the woody There are several insects that can potentially damage many skeleton is exposed (Fig. aloes, cacti, agave and yuccas. Most do not require chemical 14) treatment for adequate control. A healthy, non-stressed plant The pathogen, E. cac- will withstand the occasional insect better than a plant Figure 13. Bacterial necrosis of saguaro causes ticida, survives in soil or stressed by planting in poorly-drained soil, improper plant- exudation of dark brown liquid

6 The University of Arizona Cooperative Extension ing location, and general neglect. Whenever purchasing cacti, Cholla cacti are attacked by the beetle when the adults agaves or yuccas, examine the plant carefully to avoid bringing lay their eggs, hatch and the larvae burrow into the stems. the insects home with you and infecting your other plants. Waste (frass) is pushed out the entry holes and forms a black crusty deposit on the canes. Larvae may burrow into plant Agave Snout Weevil (Scyphophorus acupunctatus) roots and cause collapse and death of the plants. The adult weevil attacks many species of agave. The very Cactus is controlled by hand picking the large or century plant is more susceptible to insects off infested plants. The are most active and weevil damage than the smaller species. The adult weevil easier to detect and destroy in the early morning or late is about ½ inch (12 mm) evening, especially after warm summer rains. Very spiny in length, is brownish- species are less likely to have damage from the beetle due black and has a dull to a natural defense by the spines. Chemical control is not body (Fig. 16). The adult recommended since the populations usually are not high female enters the base and hand picking is effective. of the plant to lay eggs. Decay microbes also en- Cochineal scale (Dactylopius coccus) ter through this injury Prickly pear (Opuntia and as the tissue rots, species) and cholla cacti Fig. 16. Adult Agave Snout Weevil (Scyphophorus the plant has a wilted ( species), acupunctatus). Actual size approximately ½ inch appearance. Infested are attacked by cochineal (12 mm). plants soon collapse scale. The insect covers and die (Fig. 17). The itself with a waxy coat larvae (grubs) devel- that makes it appear as op in the dying plant white cottony tufts - at and infect other hosts tached to the pads and nearby. Agave snout stems of the cacti (Fig. weevil also infests the 19). To positively identi- fy cochineal scale, crush canes of several Yucca Figure 19. Waxy coat of cochineal scale species. the waxy coat with a pencil eraser. If the re- Control of the agave sult is a deep red materi- snout weevil is difficult. al-actually the body flu- Fig. 17. Damage to Agave caused by agave Selecting species that are id of the insect-then it is snout weevil. less susceptible and typi- cochineal scale (Fig.20). cally smaller than the cen- Cochineal scale is used tury plant is helpful, especially in areas where the problem by native peoples as a has occurred previously. With rare or special specimens, source of red and chemical prevention using a broad-spectrum insecticide ap- also as a natural food plied in spring is often effective in reducing damage. coloring in processed foods. Cactus longhorn beetle () Figure 20. Red body fluid of the cochineal Cochineal scale usu- The cactus longhorn scale on Opuntia. ally can be controlled by beetle attacks several using a strong stream of species of cacti including water to wash the insects from the plants. If the infestation prickly pear and cholla is heavy or the insects return, an application of insecticidal cactus (Cylindropuntia soap may be needed. species), barrel cactus Plant bugs (Echinocactus and Fe- rocactus species), young Caulotops barberi, small saguaro cactus (Carn- plant bugs measuring about egiea gigantea), and oth- 1/16 0.6 inches (1.6mm) long, ers. The adult beetle is at- tack agaves and other ro- Figure 18. Cactus longhorn beetle feeding on about 1 to 1¼ inches (2.5 sette succulents (Fig. 21) Large Opuntia. - 3 cm) long, shiny black, pop- ulations may be found on and has distinctive white markings on the antennae. The any given plant. The popula- antennae are often longer than the overall body length of tions reach damaging numbers the adult beetle. Damage to the plants is the result of feed- i n late summer or early fall. ing on the margins of prickly pear pads or terminal buds of Alex Wilde 2006 © The bugs feed on leaves and other cacti (Fig. 18). Fig. 21.Agave plant bug (Cautotops barberi) cause a light yellow-tan magnified

The University of Arizona Cooperative Extension 7 scar at the point of feeding ticides are absorbed and moved within plants and as the insect (Fig. 22). If left untreated, feeds on the plant they are killed. the plant will decline and eventually die. Mites Mites are not insects, Caulotops barberi may be but are closely related controlled by using in- to . Mites are secticidal soap or a broad very small and can be spectrum ornamental observed only with a plant insecticide. Chemi- magnifying lens or mi- cals should be applied in croscope. The mites that Figure 22. Damage to Agave caused by minute early morning or late eve- attack aloe and other plant bug. ning when the bugs are species such as Hawor- most active. Several ap- thia and are eri- plications of the insecticid- ophyid mites, a group of al material may be needed Figure 25. Galling and distorted growth of aloe plant-feeding mites that for complete control. caused by aloe mites. often cause galling or ab- A larger species of plant normal growth of the host plant tissues (Fig. 25, Fig. 26). Un- bug attacks prickly pear like their mite relatives that have four sets of legs, aloe (Opuntia spp.) and leaves a mites have only two sets of legs. They cause malformations tan scar at the point of feed- in plants by injecting a chemical that induces galling into the ing (Fig. 23). The damage plant tissue. Stems, leaves and may be affected. The is cosmetic but can be re- damage to the aloe plant is irreversible, and infected plants duced by application of in- should be removed. After removal, place all infected plants in secticidal soap or a broad Figure 23. Damage caused by leaf footed plant plastic trash bags to prevent re-infestation of remaining plants. spectrum insecticide. bug. Two spotted mitesTetranychus ( urticae) also attack certain Coccid scale, soft scale species of Yucca (e.g. Yucca gloriosa, Y. aliofolia, and Y. recur- Agaves that are stressed vata). They are difficult to see, but under a microscope, two are more susceptible to spotted mites are about 0.02 inches (0.5mm) in length and are soft scale (Coccid spp.) The red, pink, or yellow-green in color with two dark spots on stress may be the result of their body. They have eight legs and no wings or antennae. inadequate water or poor The mites leave a tell-tale speckling of he foliage that eventu- growing conditions. Ne- ally turns tan or gray. With severe infestations, a fine webbing glected plants are most is also present on the undersides of the leaves. When mite in- vulnerable and should be festations get out of control, the plant will slowly die. inspected regularly for Two spotted mites are controlled by maintaining high hu- signs of all pests. By the midity around the plant using periodic misting or washing. time the scale is discov- Washing also will re- Fig. 24. Coccid scale on Agave spp. ered, the plant may be ir- move mite webbing and reparably damaged. help reduce mite popu- Scale insects firmly attach themselves to the agave leaves lations. Chemical control and damage the plant by sucking the plant juices from the includes products known leaves (Fig. 24). Soft scales have a flattened, plate-like cover as acaricides. Always that, when the insect reaches adulthood, is less than 1/8 inch check and carefully fol- (3.0 mm) in diameter concealing the actual insect body that is low the label instructions underneath the ‘shell-like’ cover. If left untreated, the scale will for effectiveness and eventually kill the plant or cause enough cosmetic damage to safety make the plant unattractive. Figure 26. Eriophyid mite damage on Opuntia sp. One option for control of coccid scale is to separate the in- fected plants from the healthy plants. Provide plants with good growing conditions and proper cultural care and appropriate Animals irrigation, so they are more resistant to scale attack. If the scale Ground squirrels, pack rats, rabbits and mice can severely is only attacking an individual plant, discarding the plant is damage agaves, yuccas and cacti. Aloes are relatively free of the best control. When large groups of plants are infected, ju- rodent damage. During periods of prolonged drought these dicious sprays of a systemic insecticide such as imidacloprid mammals attack and destroy both mature and young plants. (Merit®) or acephate (Orthene®) are effective. Systemic insec-

8 The University of Arizona Cooperative Extension Damage of the foliage is very typical (Fig. 27, For more information Fig. 28). If the damage Agaves of Continental , Howard Scott Gentry. The is not too severe the University of Arizona Press, Tucson, Az.85721, 1982. plants will recover, but Agaves, Yuccas and Related Plants - A Gardener’s Guide, Mary and prized specimens may be Gary Irish. Timber Press, Portland., Oregon, 2000. Or: www. irreparably damaged. In timberpress.com some cases damage is so Southwest Smart Garden Region Guide, American Horticultural severe that the plant dies. Society. Rita Pelczar and Pat Welsh. DK Publishing, Inc., New York, N. Y.10014, 2004 Or: www.dk.com Figure 27 Rabbit damage of Opuntia. Control measures include exclusion of The University of Arizona Cooperative Extension Bulletins: the pests by fencing, Cactus, Agave, Yucca and Ocotillo, Bulletin Az1225, University of using live and other traps, Arizona, and Life Sciences College of Agriculture, Tucson, and using poison baits. Arizona, 85721 Poison baits should be used carefully and according Control of Bacterial Necrosis of Saguaro. Bulletin # 8837, University to the manufacturer’s of Arizona College of Agriculture and Life Sciences, Tucson recommendations since they Arizona, 85721 may cause injury or death How to Transplant a Cactus, Bulletin #1376, University of Arizona of non-target animals such College of Agriculture and Life Sciences, Tucson Arizona, as . Fencing should 85721 completely surround the Visit this website for more gardening information: plants and be buried 4‒6 Fig. 28. Rabbit damage on Agave spp. cals.arizona.edu/gardening inches (10‒15 cm) below or Cooperative Extension publications at: ground to prevent the animals cals.arizona.edu/pubs from burrowing underneath. Only through diligence can Visit this website for more information on plant diseases these pests be controlled. http://www.ag.arizona.edu/PLP/plpext/ In times of drought, larger animals such as javelinas (wild ) will often grub out many desert plant species. They eat the roots and small portions of the foliage. Fencing is the only effective solution to this problem. Fencing should ARIZONA COOPERATIVE be sturdy and at least 4 ft. high. The bottom 4 - 6 inches (10 - E TENSION THE UNIVERSITY OF ARIZONA COLLEGE OF AGRICULTURE AND LIFE SCIENCES 15 cm) of fencing material should be buried below grade to prevent rabbits from borrowing under the fence. Commercial The University of Arizona growers have reported success with electric fences that deter College of Agriculture and Life Sciences both rabbits and javelinas. Tucson, Arizona 85721

Jack Kelly Commercial Horticulture Agent, Pima County Cooperative Extension

Mary W. Olsen Extension Plant Pathologist, School of Plant Sciences

Contact: Jack Kelly [email protected]

This information has been reviewed by university faculty. cals.arizona.edu/pubs/crops/az1399.pdf Originally published: 2008

Other titles from Arizona Cooperative Extension can be found at: cals.arizona.edu/pubs

Any products, services, or organizations that are mentioned, shown, or indirectly implied in this publication do not imply endorsement by The University of Arizona.

Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, James A. Christenson, Director, Cooperative Extension, College of Agriculture & Life Sciences, The University of Arizona. The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.

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