potato guide final

8/10/2019 Potato Guide Final

1/7

rowing Potatoes

in Your Home arden

AGuidetoGrowingPotatoes

InYourHomeGarden

Yespotatoesare

nutritious! Theyarea

greatsourceofvitamin

C,potassium,fiberand

protein,

all

with

no

fat!

Potatoes,alongwith

manyothervegetables,

canbepreparedas

partofahealthydiet.

Luckily, potatoesare

versatileandareeasy

toprepare.Whether

baked,boiled,roasted

orfriedtheyarea

deliciousadditionto

Potatoesare

native

to

the

AndeanregionofSouth

America. Europeanexplorers

introducedthepotatoto

Europein1536butitdidnot

arriveintheUnitedStates

until1719whenIrish

immigrantsbroughtthe

potatowiththemtotheNew

World.

Haveyouevergrownpotatoesin

yourgarden?

Growingpotatoesisfunandnotthathard!

Homegardenerscangrowuniquevarietiesthat

arenotsoldinlocalsupermarkets.Potatoes

comeinalldifferentshapes,sizesandcolors. Did

youknow

that

there

are

purple,

red

and

yellow

potatoes?Potatoesmakeagreatgardenproject

foryourchildrenorgrandchildren.

Kelly

A.

Zarka,

Donna

C.

Kells,

David

S.

Douches

and

C.

Robin

Buell

Michigan

State

University

anymeal.

Shouldyoueattheskin? Yes! Werecommend

it! Theskinofthepotatocontainsthemajority

ofthepotato'sfiber,andmanyofthenutrients

arelocatedclosetotheskin.Washthepotato

thoroughly,cutawaygreendiscolorationand/or

sprouts,andenjoyyourpotatowiththeskinon.

Potatoesarethenumberonenongrainfood

cropintheworld. IntheUnitedStates,over1

millionacresareplantedeachyearfor

commercialproduction. Potatoesare

importanttodevelopingnationsaswell.

Potatoescangrowinharshclimatesandmany

potatovarietiescanbeproducedin90daysor

lessonsmallparcelsofland.

Potatoes

are

important

in

our

world!

Figure1.Childrenlovehelpinginthegardenand

gettingdirtyisanaddedbonus.

Figure2.

Source:

U.S.

Food

and

DrugAdministration

Arepotatoesnutritious?

Wheredidpotatoescomefrom?

MichiganState

University

and

the

Potato

Breeding

and

Genetics

Program

Figure3.Peru,South

America.Photocredit:

AllardSchmidt


2/7

Allabout

potatoes

ThepotatoisamemberoftheSolanaceae

(nightshade)family,whichincludestomato,

pepper,eggplant,petuniaandtobacco.

Theenlarged,edible,undergroundstorage

portionofthepotatoplantiscalledatuber.

Thetuberdevelopsfromundergroundstems

calledstolons. Dormantbuds(eyes)developon

thetuber. Tuberformationbeginswhenplants

are6to

8inches

tall,

or

five

to

seven

weeks

afterplanting,andresultsfromtheproduction

andmovementofstarchintothedeveloping

tubers. Manyvarietiesdevelopfruitsand

flowers,butthesepartsarenotedible. The

fruitslooklikesmallgreentomatoesand

containthetrueseedofthepotatoes;however

theyaregeneticallydifferentfromtheparent.

Plantsgrownfromthisseedwillnotnecessarily

resembletheoriginalvariety. Commercial

potato

production

and

home

gardeners

use

tuberpiecescontainingatleastonedormant

bud(eye)thatwillsproutandformapotato

plant.Thesetuberpiecesaresometimes

referredtoaspotatoseedorseedpieces.

Thepotatoisraisedasanannualcrop,however,

tubersleftinthegardenthatdonotcompletely

freezeduringthewinter,mayemergeas

volunteerpotatoplantswhenthesoilwarms

again.

Potatotypes

and

uses

Potatovarietiesvaryaccordingtoshape,flesh

colorandskinappearance. Theyareclassified

accordingtothetubertypeslistedbelow(see

Figure4).

Long

Russet

(A): Athickskinnedpotatowitha

longshapeanddrytexture;goodforbakingand

frying(Frenchfries).Thisisthemostpopular

markettypeintheUnitedStates.Variety

example:Goldrush.

Allaboutpotatoes

Round

white/Long

white

(B):

Athinlightbrownskinned allpurposepotatowithfirm,

creamytexture;bestforboilingandfrying.

Varietyexamples: Onaway,Kennebec,Superior

(Round),

Shepody andCalWhite(Long)

Round

red

skin

(C): Athin,redskinnedpotato

withfirm,creamytexture;goodforboiling.

Varietyexamples:RedNorland,Chieftainand

RedPontiac.

Yellow

(D):

Thereare

several

varieties

with

thin,

goldenskinsandcreamysmoothyellowflesh;

goodforboilingandfrying,someforbaking.

Varietyexamples:YukonGold,YellowFinn.

Round

Red

skin

yellow

flesh

(E):Newvarieties

withvariouscolorcombinationsarebeing

releasedeveryyear.Oneexampleisared

skinnedpotatowithcreamyyellowflesh.Good

forboiling.Varietyexample:RedGold

Purple

(F):Avioletpurpleskinnedpotatowith

purpleflesh;forbakingandfrying.Theyretain

theircolor

when

cooked.

Variety

examples:

AdirondackBlue,PurpleMajesty

Fingerlings

(G):Smallvarietiesthatarenarrow

almostfingershaped.Fingerlingsarefully

maturewhenharvested.Varietyexamples:

Banana,RoseFinnApple.

Figure4:Potatoescomeinmanyshapesand

colors.

Photo

credit:

U.S.

Potato

Board

A B

C

D

E

FG


3/7

VarietySelection,SeedPurchasingandSoilPreparation

VarietySelection

Choiceofapotatovarietyforgrowinginahome

gardendependsonfactorssuchasgardenspace

availability,desireduses,andstorageplans.

Toensurequalityandmaximumproductivity,

purchasecertifiedseedtubers. Certifiedpotato

tuberseedisseedofaknownvarietyproduced

understrictstandardstomaintainseedtubers

thatarevirusanddiseasefree. Savingtubers

fromyour

garden

will

eventually

result

in

decreasedyieldsandsmalltubersduetomore

incidencesofdisease.Forthesamereason,you

donotwanttoplanttubersfromthegrocery

store. Grocerystorepotatoeshavebeentreated

topreventsproutingsoitmaybedifficultto

evengetaplantstartedatplantingtime.

Certifiedpotatotuberseedcanbepurchasedat

areagardennurseriesorthroughtheinternet. If

youareinterestedintryingneworunique

varieties,try

purchasing

from

reputable

online

vendorsincluding:

IrishEyesGardenSeeds

http://www.gardencityseeds.net

WoodPrairieFarm

http://www.woodprairie.com

GardensAlive!

http://www.gardensalive.com

Burpee

http://burpee.com

Potato

Garden.com

http://www.potatogarden.com

SeedPreparation

Dependingonthesourceandthequantityyou

buyyouwillreceiveeithersmalltubersorlarge

tubers. Smalltubers(1to2inchesindiameter)

canbeplantedwhole. Cutlargetubersinto

blockshaped,2to21/2ounceseedpieces

(aboutthesizeofanegg)(Figure5).Theseed

piecesshould

be

firm,

with

at

least

one

eye

persectionandamaximumsproutlengthof

1/4to1/2inchtoensureoptimum

germination. Seedtuberscanbecutand

plantedonthesameday,howeverallowingthe

cutsurfacetohealoverfor47daysmay

reducetheriskofseedpiecesrottinginthe

soil.

Figure5: Tuberseedpiececuttings.

SoilPreparationandFertility

Potatoesgrowonawiderangeofsoils,butare

bestsuitedtoasandyloamorasoilthatiswell

drained. Verysandysoilsmayrequireextra

wateringtomaintainadequatesoilmoisture.

Finetexturedsoilsthatarehighinsiltsandclay

maynotbewelldrained,andtheytendto

producepoorlyshapedpotatoes.

Ifpossible,

asoil

test

can

be

performed

before

planting. ContactyourlocalExtensionoffice

fordetailsonsoiltesting. ThebestsoilpHfor

potatoesisbetween5.5and6.0.ApHabove

6.0mayincreasetheincidenceofcommon

scab(adisease)ontubers.Ifasoiltestisnot

available,followtheserecommended

guidelines:

Rototill intotheseedbedabout2poundsper

50feetofrowof121212(NPK)analysis

fertilizer.


4/7

PlantingandCareofPotatoesinYourGarden

Besidetherow,apply1/3poundper50feetof

rowof4600(urea)fertilizeroneweekafter

plantemergenceandagainbetween4and6

weeksafteremergence. Insteadofworkingthe

fertilizerintothesoil,waterthoroughlysothat

thefertilizermovesintotherootzone.

Donotamendthesoilwithlimeormanureinthe

sameyearthatpotatoesaretobegrown.Lime

andmanureincreasetheriskofpotatoscab

disease.

PlantingandCare

Potatoesareacoolseasoncrop;ideal

temperaturesforcropgrowthare65to80during

thedayand55to65atnight. Thesoilshouldbe

cultivated6to8inchesdeepinthespring,and

largesoilclodsshouldbebrokenuporremoved

beforeplanting. Plantpotatoeswhensoil

temperaturesareabove45F. Cold,wetsoilat

plantingtime

increases

the

risk

of

seed

piece

decay,andplantingintocool,drysoilscancause

delayedsproutingandemergenceofthe

potatoes.

Figure6:Plantseedpieces3to4inchesdeepand

space9to12inchesapart.

Planttuber

seed

pieces

3to

4inches

deep.

Leaving30to36inchesbetweenrowsand

spacingseedpieces9to12inchesapartin

therowwillgenerallyproduceanacceptable

yieldofmediumsizedtubers(Figure6). Five

poundsofseedpotatoesshouldplant40

feetofrowwith12inchesbetweenseed

pieces. Youcanexpect toharvest3to5

poundsofpotatoesperpotatoplant. Larger

tubersareproducedatwiderplantspacings,

thoughsome

varieties,

for

example,

Yukon

Gold,developgrowthdefectssuchashollow

heartatawiderspacing.

Potatoplantsshouldbehilledwhenthe

plantsare8to12inchestall(Figure7).

Figure7:Whentheplantsare812inchestall

theyshouldbehilledtokeeptuberscoveredand

preventgreening.

Moundthesoiltoaheightof3to6inchesand

approximately12to15inchesfromthebaseof

theplant.

Use

care

to

prevent

damage

to

the

plantroots,whichmayextend8to12inches

fromthebaseoftheplant. Hillingmaintains

suitablesoilcoverfortubersastheyexpand.

Tubersthatbreakthesoilsurfacemayhave

greenareasthatcontainbittertasting

glycoalkaloids andshouldnotbeeaten.Discard

orcutoffthegreenportions.


5/7


Avoidplantingpotatoesinthesamelocation

yearafteryear. Tolowertheriskofdisease

andinsectproblems,donotplantinareas

wheretomatoes,peppers,eggplants,radishes

orbeetsweregrownthepreviousyear.

WaterRequirements

Potatoesareverysensitivetosoilmoisture

anddobestwithaconsistentsoilmoisture

level.

Even

soil

moisture

levels

throughout

the

rootzoneshouldbemaintained,thoughover

wetandsaturatedconditionsshouldbe

avoided. Ingeneral,1inchofwaterperweek

fromrainfallorirrigationisadequate. As

muchas2inchesperweekmayberequired

onsandysoilswithloworganicmatter.

Drysoilalternatingwithperiodsofsaturated

soilcanresultinpoorqualitytuberswith

defectssuchasknobs,growthcracks,hollow

heart

and

internal

browning.

Long

periods

of

excessmoisture,particularlynearmaturity,

mayleadtodecreasedyieldsandpoorquality

tubers.

PestandDiseaseControl

Youcanhelpalleviatepestproblemsby

changingthelocationinyourhomegarden

wherepotatoesareplanted,throughregular

inspection,andbyremovingvolunteer

potato

plants,

which

can

serve

as

a

host

for

diseasesthatcandamagethenewcrop.

Shallowcultivationispreferredforweed

control. Forlateseasonweedcontrol,pull

weedsinsteadofhoeingthemtoprevent

tuberdamage. Mulchescanbebeneficialin

weedcontrolaswellashelpingtomaintain

soilmoisture.

Scabdiseasemaybeaproblem(Figure8).

Scabiscausedbyacommonsoilborne

organismthatcausesdiseaseonlyontubers.

Somevarietiesaremoreresistantthanothers

toscab;tolerantvarietiesincludeOnawayand

Superior. Tuberswithscabarefinetoeat. Just

peelorcutoffthecircularroughskin.

Figure8:Commonscabdiseaseinpotato.

InsectssuchastheColoradopotatobeetle

(Figure9)canbecontrolledbydestroyingeggs

whicharelaidontheundersideoftheleaf. This

canbedonebycrushingtheeggsorremoving

theleafwiththeeggsanddisposingoftheminthetrashawayfromthegarden. Additionally,

youwillwanttoremovelarvaandadultsby

hand,disposingofthemwhenthenumbersare

small.

Thepotatoissubjecttoseveralseed,foliarand

tuberdisordersthatmayaffectqualityand

appearance. SeeTable1(Page 6) for

informationonthepotatodisordersmost

commontohomegardeners.

Figure9:TheColoradopotatobeetleeggs,larvae

andadultstages.


6/7

CommonProblemsinHomePotatoGardens

Table1. Potatodisorders,causesandremedies

Symptom PossibleCause Remedy

Seed

Disorders

Rottedseedpieces Soiltoowet/coldortoohot/dryatplanting Plantwholeseedwhensoiltemp.is>45F

Foliar

Disorders

Reddishbrowndecayorlesionson

sprout,belowgroundstemandstolons

Rhizoctonia:developsincoldwetsoilsand

whenseedisplantedtoodeep(>34

inches)

Plantwhensoiltemp.isabove45F;plant

seedpieces34inchesdeep

Black,wet

rot

of

stem,

mostly

at

ground

levelBacterial

soft

rot;

referred

to

as

"Blackleg" Plant

whole,

certified

seed

Reducedplantgrowth,palegreenor

yellowleafcolorandinwardrollingof

lowerleaves

Leafrollvirus Purchasenewcertifiedseedandcontrol

aphidstopreventspread

Olderleaveshavesmall,dark

brown/blacklesionswithconcentric

rings. Usuallyonmaturingorstressed

plants.

Earlyblight Removeinfectedfoliagefromgarden area

Avoidplantstressesbysupplying

adequatewaterandnutrients

Dark,watersoakedareasonleavesand

stems.Mayseeawhitemoldgrowthon

theundersideofinfectedleaves.

Lateblight Removeinfectedfoliage fromgardenarea

Keep foliage drybywateringatthebase

oftheplant.

Yellowing

of

lower

leaves

and

early

leaf

drop Normal

maturing

or

nitrogen

deficiency Add

nitrogen

to

the

soil

and

water

Leafandpetioledefoliation;presence

oflarvae,adultbeetlesand/orbright

orangeeggmassesontheundersideof

leaves.

Coloradopotatobeetle Byhandcollectinsectsinacontainer,

placeinfreezerfor1houranddiscard.

Leafdamageincluding:irregularholes,

drybrownleafmargins,inwardleaf

rolling

Insectdamagefrompotatoleafhopper or

cabbagelooper

Byhand collectinsectsinacontainer,

placeinfreezerfor1houranddiscard.

TuberDisorders

Greenskin Exposuretosunorotherlight

Developsovertime

Hillaroundplants,storepotatoesinthe

dark

Raisedand/or

pitted

corky

areas Common

scab Use

certified

seed

of

resistant

varieties.

Avoidlimeormanuretheyearpotatoes

aregrown.Avoidcarrots,beetsand

radishesaspriorcrops

Knobby,misshapentubers Physiologicalfrominconsistentmoisture

levels

Provideuniformgrowingconditions

Splitsinthetuberthatarehealedover

"growthcracks"

Physiological (for example:inconsistent

moisture levels)

Provideuniformgrowingconditions

Large,shallowgougesintubers Whitegrubs(largebrown/creamlarvae

oftencurledintoaCshape)

Gardensnearlonggrassareatgreater

risk

Browncavitiesneartheheartofthe

tuber

"hollow

heart"

Physiological(seedpiecesplantedtoofar

apart;

inconsistent

moisture

levels)

Plantseedclosertoavoidoversized

tubers;

water

consistently


7/7


Harvesting

Timeofmaturityvariesforeachvariety.

Indicatorsoftubermaturityincludecomplete

vinedeath,skinset(tuberskindoesnotpeel

fromthefleshwhenpressureisapplied)and

desiredtubersize. Maturetubersstorebetter

andarelesslikelytobruiseordecaythan

immaturetubers.

New

or

small

tubers

can

be

harvested

early

withoutdestroyingtheentireplantbycareful

diggingandremovingsomeofthetubers. The

remainingtubersshouldbelefttogrowand

reachfullmaturity.

Harvestpotatoesbeforeaseverefrost. Usea

spadeorforktoloosenthesoilandgentlylift

thetubersoutofthesoil(Figure10). Toprevent

greeningandsunburndamage,donotallow

tuberstobeexposedtolightafterharvesting.

Figure10: Sincepotatoesgrowunderground,

harvesttimeisalwaysabigsurprise!

Storage

Fortwotothreeweeksafterharvest,store

tubersinthedarkat55to60Fwithhighrelative

humiditytohealbruisedanddamagedareasthat

couldprovideentrancefordiseaseorganisms.

Storeonlythehealthypotatoesthatare

reasonablyfreefromsoil.

Afterhealing,properstorageconditionsshould

includecool

temperatures

(near

40

F),

darkness

topreventgreening,highhumidityandadequate

ventilation. Storingtubersinplasticbags(orany

tightlysealedcontainer)willrestrictthe

movementoffreshairaroundthetubersand

canleadtorot. Storeabovefreezing(rootcellar)

orgarageifitdoesnotfreeze.

Acknowledgements

Theauthorswishtoexpresstheirappreciationto

thefollowing

for

efforts

in

producing

this

guide:

MSUPotatoBreedingandGeneticsProgram.

DanielZarka,JosephCoombs,KimberlyFelcher,

KarenRenner,RichardChase,AnnaZarka,Evan

Zarka

VisitMSUsPotatoBreedingandGenetics

Programwebsiteat

https://www.msu.edu/~douchesd/

MichiganState

University

and

the

MSU

Potato

Breeding

and

Genetics

Program

potato guide final

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