VOL. 8, NO. 6 The University of Arizona Cooperative Extension JUNE 1997

Cochise County Master Gardener

Nen/diette^,The University of Arizona and U.S. Department of Aqnculture cooperating.

PLANT PROFILE-

Desert Willow

Botanical name: Chilopsis linearisFamily: BignoniaceaeRange: Dry washes between 1,500 and 5,000feet throughout the Southwestern United Statesand Northern Mexico

Desert willow is not a true willow but with

it's long, slender weeping leaves it's a bettersubstitute than the willow for the arid southwest

region. A fast groAving tree, it cangrow2-3 feeta year and reach heights of 30 feet. By natureit's a multi-trunked tree but can be prunedinto asingle trunk specimen or grownas a small shrub.Because it lacks thorns and the roots are not invasive, it can be planted close to walls and pavings without causing structural problems.

The flowers are fragrant, orchid-like and hangin clusters of five or more and range from whiteto pink to purple. Blooming from April to latesummer the flowers are frequently visited byhummingbirds and butterflies. Desert willow isdeciduous and the 8 inch seed pods will hang onthe tree through the Avinter sometimes giAang it a"shaggy appearance."The pods may be trimmedoff, but consider leaving them on to providefood for birds. Inspection of a pod will revealslender seeds with "hairs" on it. Hummingbirdsuse this to build nests Avith.

Desert willow prefers full sun but c^ takepartial shade. Tolerant of drought, heat, wind,and cold, once it becomes established it can sur-Aidve on rainfall alone. A deep watering once amonth during the hot season will keep it moreattractive looking. Discontinueirrigationin earlyfall as new groAvth can be damaged by frost.Thinning and shaping is best done in early summer. Seeds need no pretreatment for germination and desert wiQow are very easy to growfrom seed. Because it has a very long tap root, Ifind it easier to start them in one gallon buckets.Plants will bloom the first year.

A related species, Chitalpa, Chitalpa X tash-kentensis, is a hybrid of the desert willow andcatalpa. Taking the best of both worlds, it matures at a height of 25 feet with a rounded canopy of stout branches. The leaves are darkgreen, an inch wide and three inches long whichproduces denser shade than the desert Avillow.The flowers are larger, bloom profusely, and aresterile so does not produce seed pods and givesit a cleaner appearance in winter. Taprooted likeit parents, it can also be planted near structuresand shares the same tolerances of harsh desert

conditions.

Chilopsis linearis - grow a grove of them!

Cheri Melton

Master Gardener/Staff Writer

Cochise County Cooperative Extension1140 N. Colombo, Sierra Vista, AZ 85635(520) 458-8278, Ext 141

450 Haskell, Willcox, AZ 85643(520) 384-3594

Cuttings'N'

Clippings• Peggy Dierking has pellet-fed horse manure - free, youhaul. CaU her at 378-7125

(leave message).

• Cochise County Master Gardeners Association will be cele

brating the graduation of thenew Master Gardener class at a

picnic on June 17. For information, contact Carolyn at458-0272.

• The June 19 meeting of theSierra Vista Area Gardener's

Club will be a tour ofMt. View

Aquatic Plants. The group willleave promptly at 1:30 pm fromthe Ace Hardware parking lot inSierra Vista. Questions? CallYvonne at 378-2833.

• Remember, Cado Daily ofthe WaterWise Program is available for free water audits of

your property. Call her at458-8278, Ext. 141.

Newsletter Staff:

Peggy DierkingCarolyn GruenhagenCheri Melton

Virginia Westphal

Robert E. Call,Extension Agent, Horticulture

Pnae 1

Puncturevlne(aka Goathead,

Sandbar)

Tribulus lerrestris L.Zygophyllaceae(Caltropfamily)

Puncturevlne, Goathead,Sandbur. No matter what thename, children without shoes,most outside dogs, and bicycletires, soon know the presenceofthis weed. Unfortunately, itreadily attaches to the soft solesof most shoes and is too easilybrought into one's home whereit hides in carpeting and rugs,waiting to vaccinate the barefoot of its next victim.

Known for its dark-green,trailing stems, Puncturevlneboasts up to eight small pairs ofoval-shaped leaflets. Its strikingly bright, tiny yellow flowersare divided kito five petals, andare highly attractive. The spinyfinit and sharp burs break intofive sections, with each sectionsporting up to four seeds. Julythrough October are the seed-bearing months for this weed.The seeds can remain dormantin soil for up to five years andwill grow in almost any location: fields, pastures, roadsides,even in cultivated lawns.

This weed is undesirable in

hay and may cause injury tolivestock. The bur damageswool. The puncture-likewounds in the feet of children/adults and in the pads of dogfeet may cause infections todevelop.

Eradication of this weed takes

persistence. All too often.

especially oii large tracts ofproperty in Cochise County, thisweed is ignored, and the seedsare permitted to develop andspread in abundance.

Peggy DierkingMaster Gardener/Staff Writer

Water Factoids

> The human body is morethan three-quarters water. Water is essential to existence, notonly for people but for plantsand animals as well.

> Water, when evaporatedfrom the world's oceans by theheat of the sun, leaves its saltbehind. Winds blow moisture

inland where clouds are formedand some of the water falls to

earth as rain or snow. Then, byone route or another, it returnsto the ocean.

> In the Denver area, approximately 500 gallons per day perhousehold are used, and an average of 150 gallons per household are used before breakfast.

The average daily use in Canadais 1,090 gallons per person, inAustralia it is 876, in Great Britain 185 gallons and in Switerz-erland they only use 77 gallonsper person per day.

-Denver Water Department

The Virtual Gardener-

Alkaline Soils

As I attempt to dig plantingholes on my property at thistime ofyear I am reminded onceagain of just how poor my soilis—at least "poor'' in comparison with those beautiful rich,fluffy loams I see in gardeningmagazines and on television.This prompted me to see what Icould dig up about soils on theInternet. My search was rewarded with an excellent Web

site maintained by the Cooperative Extension of Colorado

State University (http://www.coIostate.edu/Depts/CoopExt/PUBS/pubsmenu.html.)

Water, as most ofus know, ismade up of hydrogen and oxygen in a ratio of two parts hydrogen to one part oxygen(hence the famous formulaH2O). At any particular time in acontainer ofpure water, most ofthe water molecules remain

bonded together while a verytiny number break apart intofree hydrogen ions (IT) and freehydroxyl ions (OH). Normallythere are equal concentrations(about one part in ten million)of each of the hydrogen and hydroxyl ions. A solution withequal numbers of both ions issaid to be neutral, but if something upsets the balance and se

lectively removes either hydroxyl or hydrogen ions, thesolution is said to

become either

acidic or basic (alkaline). Acidsolutions have a larger concentration of free hydrogen ions,and alkaline solutions have alarger concentration of free hydroxyl ions.

The relative acidity or alkalinity of a solution is expressed aspH, which is a measure of therelative number of free hydrogen ions. The pH scale is a littletricky because it's inversely proportional to the concentration ofhydrogen ions, that is, a higherpH number indicates fewerrather than more hydrogen ions.(Forthe technically inclined, pHis the negative of the base 10logarithm of the reciprocal ofthe concentration of free hydrogen ions). A solution with a pHof 7 is said to be neutral. Solutions withpH values higher than7 are alkdine, and those withpHvalues less than 7 are acidic.Another twist to the pH scale isthat each unit value on the scaleindicates a tenfold increase ordecrease in the number of freehydrogen ions. For example asolution with a pH of 6 is tentimes more acidic than a solution with a pH of 7, and onewith a pH of5 is ten times moreacidic than a solution with a pHof 6 and 100 times more acidicthan a solution with a pH of7.

The details of the chemical re

actions that determine the pH ofsoil are complicated, but generally where there is more thanabout 20 inches of rainfall in a

year, the soils tend to be acidic.Where there is less than 20

inches of rainfall in a year, suchas here in the Hgh Desert, thesoils tend to be alkaline. This isimportant to the gardener because certain plants—especiallythose that are most familiar to

people who grew up in theEastem United States where the

soils tend to be acidic—are

adapted to grow in acidic soilsand will not do well in alkaline

soils.

Gardeners trying to growplants in the alkaline soils ofCochise County can pursue twopossible strategies. The first isto attempt to alter the pH oftheir soils by the use of amendments such as sulfiir so that theycan grow the acid-loving plantsthey remember from anotherplace. The second is to go native and grow only those plantsthat are adapted to our alkalinesoils. Although attempts tolower the pH of soils can besuccessful in the short term,

they require the repeated addition of huge quantities ofamendments to maintain even a

small change in pH. Ultimatelythe gardener will lose to Nature.The better strategy is to leavethe soil pH alone and plant onlythose plants that are adapted tothe soils of our area.

GaryA. Gruenhagen, Master Gardener(gruenha@.c2i2. com)

Call before you dig!Blue Stake

1-800-782-5348

Page 3

<J Check tree tiesy Remove stakes iftree can

stand alone

V Mulch trees & shrubsy Removed faded flowers &

fertilize roses

V Stake tomato plants &watch for curly top-remove

y Prevent blossom end rot byeven watering

y Water! Water! Water!

HummingbirdGardening

I was attracted to hummingbirds two years ago when Iplanted a lone Salvia greggii. Itwas the only plant in the garden.Two days later I heard thisstrange whizzing noise, lookedaround and to my amazement ahummer was feeding at the salvia. Since then I have collected

books and plants to attract thesejeweled beauties. (The booksare for me, not the hummers!)The best time to attract hum

mingbirds is during spring migration and this hinges on twothings: flower nectar and insects. Males arrive before the

females searching for foodsources and if found will signalto the females and the young tofollow. The average lifespanforfemales is three and a halfyearsand for males two and a half.

Since hummingbirds need tovisit between two thousand andfive thousand flowers a day tomeet their huge energy needs, itmakes sense to supplement thehummingbird garden with feeders. Males can be very territorialand sometimes claim a feeder

Page 4

for themselves so considerhanging a ,few around the garden and place them out of sightof each other. I put up a feederabout a week before the malesshow up to ensure that theystick around. I judge the time toput up a feeder by watching theSalvia greggii and when itblooms I hang the feeder. Whenhanging feeders make sure thatthere is enough air space for thebirds to escape from predators.They like to be able to see allaround them.

There are dozens of hum

mingbird feeders on the marketso which one is best? I havefound that a feeder that is easyto clean and doesn't drip is agood priority. My favorite areglass feeders. Dan True, author

of Hummingbirds of NorthAmerica, has found that a glasshamster water bottle is the favorite feeder in his garden. Withour high winds a pan or basinfeeder works well because it is

almost drip proof. You cancombat wind problems by attaching a lead fishing weightfrom the bottom of the feeder.When buying plastic feederslook for a high grade plasticsuch as cellulose-acetate-butyrate or acrylics and polycarbonates that can Avithstand thedesert heat. I also find thathandwashing plastic feeders willextend their life cycle considerably. My favorite cleaning solution is soaking them in the sinkof hot water with dishwashingdetergent and white vinegar.

The vinegar helps cut down onthe soap film making it easier torinse clean. Please note thatvinegar is an acid and can discolor metals.

The ratio for feeder formula is

four parts water to one partsugar-do not use honey or reddye in the solution. This produces a solution of 21 percentsucrose, which is the same ratioof nectar found in most hum

mingbird flowers. In the summer I up the ratio to five partswater/one part sugar. It givesthe birds more water in the heat

and keeps the solution fromgumming up. The solutionshould be boiled on the stove

for two minutes to retard fer

mentation and then cooled. A

large batch can be made and theextra stored in the refiigeratorin a glass container. Experts advise agmnst microwaving thesolution as the radiation alters

the sugar's structure. Feedersshould be cleaned and refilledevery two to four days.

To control bees on feeders re

place yellow bee guards with ared one since bees are attractedto yellow. For ants I find thatrubbing lard or Chapstick on thepole keeps them from crossingthe barrier. If bats are emptyingout the feeders simply take themin eveiy night, but bats eat suchlarge quantities of insects (over2,000 mosquitoes per night!) itmay be worth feeding them also.

The ultimate feeding stationwould also include pieces offimit that attract fhiitflies and

gnats. Next month we'll focuson nesting, plants, and waterfeatures that attract hummingbirds.

Cheri Melton

Master Gardener/Staff Writer

The Agent'sObservations

have a pear tree^^jW^Kthat has some bumps

the leaves. Over

'^^^^^time the bumps turninto brown spots. Is this zincdeficiency?

^w^^pzinc deficiency. The

'caused by mites,most likely the pear leaf blistermites (Phytoptus pyri Pagen-stecher). This mite was introduced fi"om Europe, probablybefore 1900. It is a pest of mostpear growing areas of theworld. Feeding by these mitescauses damage on leaves andfiiiit. Blister mites overwinter as

mature females at the base of

buds or under outer bud scales.

Adults are light to amber yellowin color and cylindrical, tapered

Pear leaf blister mite

(Eriophyes = Phytoptus pyri)

sharply at the posterior end andresemble a short worm. In

spring, when buds begin toswell, overwintering femalespenetrate deeper into the budsand lay eggs on live tissues. Development firom egg to adult requires 20 to 30 days duringspring. Feeding of females andtheir offspring causes blisters on

developing leaves. Blisters aregreen or red at first but turnlight brown to black as affectedtissue dies. As the blisters form,leaf cells near the center of the

blisters die and pull apart as surrounding cells enlarge, creatinga hole. Blisters vary in size, withthe largest about 1/8 inch in diameter. Mites do not live in the

blisters on the fiuit, but the fiuitwill be scarred. Mites ofthe first

spring generation enter blistersthrough these holes and feed onsoft leaf tissue inside. Several

generations develop within theblisters during a growing season. Summer generations require only 10 to 12 days todevelop. When blisters becomecrowded or leaves become

heavily damaged, mites may migrate to growing terminalswhere their feeding producesnew blisters. Fruit damage iscaused by injury to buds beforebloom. Severe damage to foliage can cause leaf drop and reduce shoot growth. Look atyoungleaves before bloom earlyin the spring just as leaves areunrolling. Noticeable light greento light red rough areas wheremites have been feeding will beseen. This damage becomesmore noticeable as the growingseason progresses.

Control: Blister mites are not

normally controlled by naturalenemies. Predatory mites willfeed on blister mites when theyare exposed. Blister mites oftenattack weak, neglected or abandoned trees. If a pesticide is

used to control blister mites the

best timing is after harvest whenmites migrate fironi leaf blistersto terminal and fiuit buds. Theyare exposed on those sites untilbuds swell in the spring. Pre-bloom treatments can preventfiuit damage that occurs just before and during bloom.Source: Orchard Pest Management. 1993. Edited by: Elizabeth H. Beers, et al. Good FruitGrower Publications, Yakima,WA Pages 151-153.

^^^^^Mv mesquite treesbrown round

bumps on many of^^^Pthe limbs. In factsome of the branches have ooze

dripping from them. Is thisscale?

soft brown

^^^^®are a "super family"of over 200 insects that feed on

plant sap while females protectthemselves with a soft or hard

"shell" body covering. Malescan be winged. Scale produceyoung by eggs or by bearing liveyoung. The young, called crawlers, may crawl out from undermother's covering and move toanother location, usually closeby, and then set up "housekeeping." One to five generationswill be produced each year depending on the species and environmental conditions. Scale are

protected by the covering theymake for themselves and it is

^ued infurtherance ofCooperative Extension work, acts ofMay 8 and June 30, 1914, incooperation with the United States Department ofAgriculture, James A. Christenson,Director, Cooperative Extension, College ofAgriculture, The University ofArizona and Arizona Counties coop^ting. The University ofArizona College ofAgriculture isanequal opportunity employer authorized to provide research, educational information and other services only to individuals and institutions that function without regard tosex,race,religion, color,nationalorigin,age,Vietnam Era Veteran's status, or disability.Theinformation given herein is supplied withtheunderstanding thatnodiscrimination isintended and noendorsement byCooperative Extension is implied.Anyproducts, services, or organizations that are mentioned, shown, or indirectly implied inthispublication donotimply en(k>rsement by theUniversity of Arizona.

Page 5

COOPEKATIVE EXTENSION

U.S. DEPARTMENT OF AGRICULTURE

s THQE UNIVERSITY OF ARIZONATUCSON, ARIZONA 85721

OFFICIAL BUSINESS

PENALTY FOR PRIVATE USE $300

very hard to penetrate withpesticides.Control: Physical removal byspraying a hard stream of watermay work, however many timesthey are stuck on the plant verytightly. Even rubbing off thescale with a stiff brush can be

effective. Using systemic insecticides can help control scalebutmany times does not work verywell. Suffocating or penetratingtheir "shell" are methods also

used to kill this pest. Dormantoil sprays are used when plantleaves are no longer than a halfinch in early spring. If used laterleaf damage may occur. Rubbing alcohol applied to scale

will penetrate their waxy shellcovering and kill them. Use70% isopropyl (rubbing) alcohol, mixing 1 to 2 cups of alcohol per quart of water. Sincealcohol can damage some plantsfirst test spray on a small area.Wait for a day or two to see ifdamage occurred. If not it issafe to spray. You can mix in-secticidal soap according to thelabel directions but substitute

rubbing alcohol for half of thewater. A recipe that has proveneffective in the past for scalecontrol and other insects is

made by mixing one cup cooking oil plus 1 tablespoon of dishdetergent (non-citms). Mix one

BULK RATE

POSTAGE & FEES PAID

USDA

PERMIT No. G268

to two teaspoons of this solution with one cup of water.Spray mixture on the infectedplant until it drips off. It is bestto spray a few leaves and thencheck for leaf bum the next daybefore spraying the entire plant.With many of these treatmentsthe scale will not drop off of theplant but will remain attachedeven though they are dead. Prysome off several days aftertreatment to determine if the

scale are dead. If not treat

again.

Robert E. Call

Extension Agent, Horticulture