rOhio Florists' Association Bulletin No. 695, Septemoer, 1987 Page 3

The Postproduction Guide For Care And Handling OfFoliage Plants For Interiors

INTRODUCTION

The useful lifespan of a foliageplant can be broken clown intofour phases. Production is by

growers,

including suchspecialities astissue culture

laboratories,plantpropagators, and

T. M. Blessington plant finishers.Postproduction storage is carriedout by shippers and wholesalers.Interior plantscapers, florists,

garden centers,and mass

marketdistributors are

responsible forthe retailhandling ofplants. The finalphase is called

consumer care, where interiorkeeping quality is determined bythe practices of the consumeralone or by a plant maintenancecompany. These phases aresignificantly distinct by functionand chronological order within theplant's lifespan; but, they are notindependent of each other. Thekeeping quality of a plant isdetermined not only by theconditions encountered during anyone phase, but is influenced atany one point in time by theinteractions of the present phasewith all proceeding ones.Decisions made within each phaseaffects potentials for success inthe other phases.

PRODUCTION FACTORS

The production phase includespropagation and growth of theplant to a finished, saleablecondition. Healthy, high qualityplants at this point are not onlyan attractive commodity, but theyalso maintain quality betterthroughout the stresses of storage,transport, and placement indoors.Production factors that influenceinterior keeping quality of a

Pamela C. Collins

Thomas M. BlessingtonPamela C. CollinsTexas A&M University.Agricultural Research and Extension

Center,2-115 East Highway 83,Weslaco, TX 78596

foliage plant are light,temperature, nutrition, water,medium, problems of disease orpests, and cultural disorders.

Light—Recommendations forproduction light levels aredetermined by genetic compositionof the species and by interior lightconditions to which the plant mustadjust. Some species are naturallyadapted to heavy shade of forestfloors and perform well under lowlight levels. Other species requirehigh light levels to grow properlyand are seldom used in interiorsettings unless sufficient directsunlight is available. A third groupof plants can adapt to reduced lightif they are produced or acclimatizedunder specific light levels. Asproduction light level is decreased,these plants become increasinglytolerant to marginal lighting.Physical changes such as growthhabit, leafsize, leaf color, and trunkcaliper usually accompany theacclimatization process. Thesechanges may or may not bedesirable to the producer ordesigner/retailer. If major changesin growth habit are not acceptable,some plants can be produced underhigh light levels and then placedunder shaded conditions until thefoliage is fully acclimatized. Thisprocess may take six weeks to sixmonths or even longer, dependingon species and size of specimen.Even then, these converted plantsare not as fully conditioned to lowlight situations as those producedentirely under shade (1).

Temperature—Plant specieschosen for use in interiors aremostly tropical plants, although afew subtropical and temperateclimate plants also perform wellindoors. Therefore, mostrecommended greenhouseminimum temperatures range from60-70°F (16-21 °C) to assureconstant, uniform growth rates.Ability to sustain short periods ofcool, non-freezing temperatureswithout chilling injury variesconsiderably by species. Likewise,ability to tolerate hightemperatures without damage orreduction in growth rate is quitevariable. Careful selection oftemperature tolerant crop speciescan be important where economy in

fuel consumption or lack of heatcontrol is a major consideration.The acclimatization process itselfisonly minimally affected byproduction temperature (2,3).

Nutrition —Fertilization duringthe production phase definitelyinfluences interior keeping qualityof foliage plants. Overfertilizationdecreases acclimatizationeffectiveness indoors, either byincreasing respiration rate or byroot damage from high solublesalts. Low levels ofnutrition reduceplant growth and quality. The mostefficient fertilizer rate and ratiodepends on many factors. ExtremepH imbalances in potting mediablock availability of essentialelements. Where clay-containingsoil is used in a potting medium, a1:1:1 fertilizer ratio isrecommended to assure adequateavailability of phosphorus andpotassium. In soilless media, a 3:1:2ratio is suggested to decreasesoluble salt levels and costs offertilizer components. Most pottingmedia require the addition ofmicronutrients. Most recentresearch reports recommend theomission of superphosphatecompletely from the growingmedium, as foliage plants do notshow a specific need for theamendment. In fact, several generaof important foliage plants aresensitive to fluoride present insuperphosphate. Fertilizer ratesalso depend on production lightlevels. Recommended fertilizer andlight levels are based on a balanceofgood growth and acclimatizationneeds. Plants produced under highlight levels may require increasedfertilizer rates, while plantsproduced under heavy shade willneed less fertilization to maintaina balanced growth. In addition,temperature affects fertilizerapplication decisions. Less fertilizeris needed during the cool seasons,and more fertilizer is requiredduring warmer times of the yeardue to difference in growth rates.Temperature levels similarly affectthe release rate of encapsulatedfertilizers. Where heavy rainfall oroverhead irrigation is a frequentoccurrence, upward adjustment infertilizer application must beconsidered (1).

Page 4 Ohio Florists' Association

Water—Perhaps the best generalrecommendation for irrigationpractices is to avoid extremes.Plants experience stress whenwatered either too much or toolittle. Frequent irrigationsstimulate fragile succulence, andexcessive water retention in themedium reduces root growth andresistance to soil-borne diseases.Insufficient water or excessivedrying of the medium betweenwaterings reduce growth andstimulate leaf abscission. Mostplants maintain good growth andquality when irrigation schedulesallow slight drying betweenthorough waterings. A few speciesrequire special considerations dueto environmental adaptations toclimates with high humidity andconstant moisture or to climateswith low humidity and dry soils.

Media—Water retention, cationexchange capabilities, and drainagecharacteristics of potting media allcontribute to health, growth, andkeeping quality of foliage plants.Many medium components are nowused such as bark, peat, sand,vermiculite, perlite, styrofoam,cypress shavings, and even clay soil.Mixtures of various components aredesigned for the special needs of aspecies and in response to theeconomics of componentavailability and transport costs.Soluble salts, fluoride levels, andany other suspected elementalimbalance should be checked in allmedium components beforeincorporation into the finished mix.Most foliage plants require a pHadjustment of 5.5-6.5 to grow well.Potting media usually requiremicronutrient amendments as

discussed under nutrition. Carefulattention to the mediumpreparation before planting mayavoid costly cultural disorderscaused by deficiencies, toxicities,and poor root development (1).

Problems—All foliage plants showsusceptibility to some disease orpest, although considerablevariability exists among species.Good cultural technique, consistentsanitation practices, and carefulobservation may reduce the needfor heavy chemical controlapplications. Where chemical use ismandated, test a block of plantswith the selected pesticide forsymptoms of toxicity or forundesirable deposits on the foliage.Good disease and pest controlduring production not only provides

a quality plant for sale, butimproves the probability thatquality will be maintained duringshipping. The crowded, enclosedenvironment imposed on plantsduring transit and storage is notonly detrimental to an infestedplant, but increases the likelihoodof spreading problems to healthyplants and compounding economiclosses.

Disorders—Some plantdisfigurements are not caused byattacking organisms, but byphysiological responses to internalimbalances or environmentalconditions. Susceptibility to injuryvaries considerably. Most fernsdevelop phytotoxic responses to abroad spectrum of pesticides,limiting the use of chemicals intheir production. Several importantgenera of foliage plants aresensitive to fluoride or boron ineither potting media, atmosphere,or water. Palms can display poor,stunted growth when deficient inmanganese, iron, or zinc.Production under light levelsexceeding recommendationsproduces bleached, light-greenfoliage color in some plants, whiletoo much shade destroys normalvarigation patterns and stimulatesweak, elongated growth. Chillinginjury is a major problem in severalspecies. The final result of suchdisorders is economic loss ofunsalable, poor quality plants.These plants hurt all ofthe foliageplant industry because they do notship or store well, and they requireextra regrowth time andmaintenance attention in interior

locations.

POSTPRODUCTION FACTORS

The postproduction phase existsfrom the time that plants leaveproduction ranges in shippers'vehicles and are possiblywarehoused by wholesalers untilthey reach retail locations. Theprime goal for shippers andwholesalers is to deliver plants withminimum deterioration in quality.Factors that affect keeping qualityof plants during this period ofshipping and storage are storagelight, temperature, exposure togasses, lasting qualities duringstorage, and care and grooming ofthe plants prior to packing.

Light—Transport under darkconditions is currently the mostpractical method of shipment.When plants travel a long distance,

Bulletin No. 695, September 1987

a recovery period is sometimesnecessary to recoup quality lostduring the extended period ofstress. In addition, wholesalerssometimes need to hold a shipmentof plants for a time beforedistribution. Specially equippedgreenhouses or environmentalrooms are ideal places for plantholding. Recommended light levelsfor these locations at 500 to 1,000fc (5.4 to 10.8 klx). Temperature,irrigation, and relative humidityshould approximate normal levelsfound indoors to retainacclimatization conditioning (4).

Temperature —Shippingtemperature specifications havechanged considerably with thedevelopment of guidelines forextended overseas transit. For manyfoliage plants, shipping durationscan be increased whentemperatures are reduced to levelsthat slow down physiologicalprocesses but do not cause chillinginjury. Recommendations for someplants are very specific for differentstorage durations, depending onsensitivity to injury over a longperiod oftime. Where the new long-term guidelines are not available,existing recommendations aregiven (4).

Gases—Ethylene is the gas mostfrequently generated by plantmaterial during transit; however,foliage plants are not particularlyheavy producers. Avoid mixedshipments with fruits or vegetables,which release significant amountsduring the ripening process. Plantdamage is generally not a problemwith storage below 65°F (18°C), asgas evolution and activity isinhibited by low temperature.Ethylene at levels greater than 1 to2 ppm may cause damage ifplantsare held in storage for a long timeabove 65°F(18°C) (4,5).

Lasting qualities—Stressavoidance is the key to plantkeeping quality during shippingand storage. Best quality retentionis obtained with the shortest transittime. Most prepared and packagedplants tolerate 7 days of travelwithout significant quality loss.Ability to survive longer durationsdepends on the species and shippingconditions. Some plants can beshipped up to 4 weeks withoutsignificant deterioration when heldunder carefully controlledconditions of temperature, relativehumidity, and moisture. Keeping

Ohio Florists' Association

quality is also influenced byconditions encountered during theproduction phase. Plants producedwithin recommended ranges oflight and fertilizer ship better thanunacclimatized material. Winter-or spring-produced plants toleratelower shipping temperatures thansummer-grown stock (4).

Care and Grooming—Keepingquality during the postproductionphase may be improved ifplants arewell prepared and packaged beforeshipment. Fertilization should bediscontinued at least a week priorto shipping, especially when slow-release forms are used. Loosegranules shift during handling andfall between the soil ball andcontainer. Schedule the finalirrigation so that the pottingmedium is moist, or approximately50c/c of capacity. Extremely wet ordry medium conditions aredetrimental to plant health duringthe storage period. Development ofdiseases may be reduced if thefoliage is dry during storage. Whenwet foliage is unavoidable atpacking time, lower shipping-temperatures may help retarddisease development. The shippingindustry has developed advancedequipment and handlingprocedures designed to movedelicate, perishable items such asplants. Growers may improveprotection of their commodity byusing moisture-resistant boxes orspecially developed shipping racks.Large specimens may be protectedwith sleeves that envelop thecanopy and are closed at the top.Maintenance of high relativehumidity levels of 80 to 90r'r reducedesiccation during storage time.These levels may be achieved byboxing or by placing the reefer(refrigerated van) air controller inthe closed position. The objectivesof such careful packing proceduresare to avoid physical breakage andreduce desiccation during shipment(4).

RETAIL HANDLING

The retail phase begins withdelivery by shipper or wholesalerand continues until sale to theconsumer or installation into apermanent interior location.Retailers may be interiorplantscapers, florists, gardencenters, or mass market businesses.Shipping durations and provisionsfor poststorage care determine thecondition of foliage plants upondelivery. Length of stay of

Bulletin No. 695, September, 1987 Page 5

inventories depends largely on thenature ofthe business. Regardless,basic plant care is based onenvironmental demands of aninterior location.

Light—Plants may require arecouperative period upon arrival,and the ideal location is in a holdinggreenhouse or room with lightlevels of 500 to 1,000 fc (5.4 - 10.8klx). Temperature, irrigation, andrelative humidity shouldapproximate normal levels foundindoors to retain acclimatizationconditioning. Where such facilitiesare not available, provide at leastthe minimum sustaining lightlevels given under each plantlisting. Plants held under less thanminimum light will be unable tomaintain quality for very long (4).

Temperature—Most tropicalfoliage plants maintain goodquality with temperature andrelative humidity levels that arecomfortable for humans. A fewsubtropical and temperate climatespecies have special preferences forsomewhat cooler nighttemperatures or higher humidities.

Water—Foliage plants usuallyperform best indoors when thepotting medium is moist, but well-drained. Extremely wet or drymedium conditions stress plantsand cause loss in quality. A fewspecies require special moisturerecommendations based onadaptations to native climates ofhigh moisture and humidity or oflow moisture and dry soils.

Disorders—The major problemswith foliage plants at this stage aredue to stress from shipping andstorage. Most are temporary andcorrect themselves with a littlerecouperation time in a holdinggreenhouse or room. More severelosses are incurred when latentdiseases or disorders from theproduction and postproductionphases are passed on to the retailer.

CONSUMER CARE

The useful lifespan of a foliage plantwithin its permanent interiorlocation depends largely on thesuccessful matching of a plant tothe environmental conditions of aspace and on the care provided byeither the consumer ormaintenance service. Any latentproblems brought from earlierphases will reduce keeping qualityunder interior environmentalstress and increase the effort

necessary to maintain anacceptable appearance. Factors thataffect the keeping quality offoliageplants after interior installationare temperature, location, wateringpractices, grooming, disorders, andcultivar selection.

Temperature—Most tropicalfoliage plants maintain goodquality with temperature andrelative humidity levels that arecomfortable for humans. A fewsubtropical and temperate climatespecies have special preferences forsomewhat cooler nighttemperatures or high humidities.Location —Successfulinstallations occur when plantselections are matched carefullywith interior locations. Somelocations have severeenvironmental limitations, whereplant choices are few in number.The limiting factor is usually light,or rather the lack of light. Plantswith natural or acclimatizedadaptation to low light levels arethe most successful in thesecircumstances. Ability to tolerateminimum light levels varies evenwithin this group. Changes ingrowth habit may be expected intime as plants adjust to the location.Under marginal conditions,durability and lifespan aresignificantly altered. Keepingquality potential improves wherelight can be increased. As lightingconditions approach the naturalrange of a plant, growth and qualityreach peak capabilities. At thislevel, maintenance becomes amatter of keeping growth in boundsrather than an effort to retardsenescence. Variety in species andcultivar selections also increases aslighting approaches moderatelevels. In locations that have directsunlight, marginal interior plantselections requiring high levels maybe used with good keepingexpectations. Specific guiderecommendations list bothoptimum light ranges andminimum/maximum toleranceswhere the information is known.

Water—Foliage plants usuallyperform best indoors when thepotting medium is moist, but well-drained. Extremely wet or drymedium conditions stress plantsand cause loss in quality. A fewspecies require special moisturerecommendations based onadaptations to native climates ofhigh moisture and humidity or oflow moisture and dry soils.

Page 6 Ohio Florists' Association

Grooming—Under most interiorconditions, maintenance efforts topreserve existing quality levels isrequired more often than growthcontrol maintenance. Plants are notstatic objects, and therefore growthand/or decline is inevitable.Specific recommendations attemptto identify expected trimming andrepotting needs. Less fertilizationis necessary under interiorconditions. Specific recommendationsare listed where known.

Disorders —Weak, damaged, ordiseased plants will not survivelong if placed indoors. Healthy, highquality plant material is better ableto resist the stresses of suboptimalinterior conditions. Problems thatdevelop after placement indoorsmost often are caused by low light,low humidity, drafty locations, orair pollutants. Poor maintenancecontributes to quality loss whenplants are overwatered,underwatered, undusted, poorlyfertilized, and otherwise neglected.Stressed plants are moresusceptible to attack by pests and

diseases. Considerable variabilityexists between different foliageplant species.

Cultivars—The foliage plantindustry has a wide range of speciesto provide variety in texture, color,size, and cultural adaptability. Inaddition, numerous cultivars areavailable that have marketableattributes such as increased foliagecolor, interesting variegation, orgrowth habit, disease or pestresistance, or improved ability totolerate specific interior conditions.Plant introduction or breedingprograms and tissue culturelaboratories are continually addingnew"cultivars to the market. Eachnew cultivar should be thoroughlytested to develop guidelines thatproduce a high quality plant withgood interior keeping capabilities.All available cultivars cannot bediscussed within this current guide,but where possible, commerciallyavailable related species andcultivars of the listed plants arebriefly described.

Bulletin No. 695, September, 1987

SOURCES OF INFORMATION

1. Conover, C. A. and R. T. Poole.1984. Light and fertilizerrecommendations for productionof acclimatized potted foliageplants. Foliage Digest 7(8):l-6.

2. McConnell,D.B.,R.W.Henlev,and R. L. Biamonte. 1981.Commercial foliage plants, p.544-593. In: J. N. Joiner (ed.).Foliage plant production.Prentice-Hall, Inc., EnglewoodCliffs, N. J.

3. Conover, C. A. and R. T. Poole.1984. Acclimatization of indoorfoliage plants. HorticulturalReviews 6:119-154.

4. Conover, C. A. and R. T. Poole.1986. Factors influencingshipping of acclimatized foliageplants. ARC-Apopka ResearchRpt. RH-86-11. Univ. of Florida.

5. Conover, C. A. and R. T. Poole.1983. Handling and overseastransportation of acclimatizedfoliage plants in reefers. FoliageDigest 6(5):3-4.

Canadian Floriculture Imports Into The United StatesAs a way ofintroduction, allow meto relate a little about our firm. Wegrow in excess of 40 acres of holiday

blooming plantsand azaleas oneastern LongIsland. Most ofthe production isunder glass withsome plastic.The operation isspread through

five locations. Additionally, we have12 acres of production of glass andsaran on the west coast of Florida.

We are located directly in themiddle of the region serviced byOntario, Canada growers; an areanorth and south from Boston,Massachusetts to Virginia and asfar west as Chicago. We havecompeted with the Canadians forthe last 20 years in varying degrees.Speaking for myself, and I am surefor most growers in thenortheastern United States, I wishthat Niagara Falls werea lot higher,wider, and deeper. To say that the

mRussell Weiss

Russell WeissKurt Weiss Florist, Inc.95 Main StreetCenter Moriches, NY 11934

Canadians are good tradingpartners, and that we haveopportunity here in the northeastto do business in both directionswith them, would be a completefabrication. Our 20 year associationwith the Canadians has beentotally one sided with the UnitedStates in many cases being adumping ground.

I think it is important tounderstand why Canadians havebeen so successful with theirproducts in the United States in thepast, what the situation is atpresent, and what we can do in thefuture. If we as growers bemoanthe fact that the Canadians haveunfair advantages and look forU. S. government interventionand protection, we will be out ofbusiness. Nothing has come fromour government in the way ofassistance in the last 20 years, andit is not likely to come in the next20 years. Canadian floriculturalimports are a very small part of thetrade between the United Statesand Canada. As a nation as a whole,the United States probably shipsmore merchandise to Canada thanwe receive. Agricultural products,

and specifically floriculturalproducts, are allowed into theUnited States free of duty or at verylow rates in order to appease ourforeign trading partners. Thissystem of relegating agriculture toa secondary position in our societyhas been going on for a very longtime, and will not likely change inthe future.

Historically, however, Canadianproducts would not have come intothe United States at any price werethere not a need. As the floricultureindustry in the United States grew,America growers did not fill thegap. Canadian growers were there,in the past, with acceptable qualityat good prices. I, however,emphasize was there, with goodand many times better quality.Later I will go into what exists atpresent and what I believe thefuture could hold.

In the past, Canadians were bettergrowers than their U. S.counterparts. Along with beingbetter growers goes being betterbusinessmen, better marketers,better packagers, and bettershippers. Canadian exports fromOntario to the United States have