Growing Grapes in Maine


David T. Handley, Vegetable & Small Fruit Specialist, University of Maine Cooperative Extension
January 2013


Table of Contents


Grape Expectations

What are your goals?

  • Personal
  • Financial
    • Grapes = high-risk crop
    • Invest wisely
    • Or not at all
  • Scale
    • Home Garden/Hobby
    • Commercial
  • Table Grapes
    • Market?
      • Quality, quantity, competition
  • Wine Grapes
    • Variety very limited
    • Quality/quantity of product
    • Market?

Potential (likely) Problems

  • Winter injury
    • Buds, Cane, Trunk
  • Short growing season
    • need early maturity
  • Pest Problems
    • Diseases, insects
  • Markets

The Grape Plant

Perennial Vines

  • Long-lived (?) trunk
  • Fruit on 1 yr. old canes
    • Lubrusca types: buds 3-5
    • Vinifera types: buds 1-3
  • Self-layering (rooting)
  • Self-fertile (mostly)
  • Long growing season (160+ days)
  • Winter-tender

Trunk

  • Long-lived (?), perennial
  • 1’-7’ tall, depending on the training system
  • Winter hardy to -10º to -40º

Cordon

  • Permanent branch, perpendicular to the trunk
  • Supports fruiting (1 yr old) canes
  • Improves exposure, eases harvest

Cane

  • One-year-old vine growth
  • Supports buds, fruiting shoots
  • Health of cane determines the quality of the crop
    • Most productive: moderate vigor
    • 3/8” thick
    • Chocolate brown color
  • Internodes: space between buds

Shoots

  • Current year’s growth (green)
  • Support fruit at nodes
  • Will be canes next year

Grape Growth

parts of the grape plant: cane, buds, flowers, shoots

illustration showing internode, lateral, node, and fruiting caneShoot Growth

  • Buds form at nodes
    • At leaf base
  • Next years shoots (dormant)
  • May produce laterals
  • Fruit clusters
  • 1-2 cluster/shoot
    • Remove excess clusters
    • Furthest from base
    • Better fruit size, ripening

Vine Growth

Vines can grow 15’+/year! Make sure they have adequate space and light.


Grape Varieties

What should you look for?

  • Hardiness
  • Early maturity
  • Hardiness
  • Table vs. wine quality
  • Hardiness
  • Disease resistance
    • Hardiness

Lubrusca Types
(Vitus labrusca)

  • Native, hardy
  • Sweet, strong “foxy” flavor
    • e.g. “Concord”
  • Blue/black, red, white
    • Some seedless
  • Mostly table quality
  • Limited wine utility

Vinifera Types
(Vitus vinifera)

  • European orgin
  • Not hardy
  • No “foxy” flavor, less sweet
    • e.g. “Chardonnay”, “Cabernet”
  • Blue/black, red, white
  • Limited table utility

Hybrid Types
(labrusca x vinifera [x ripera])

  • Interspecific crosses
  • Improved hardiness over vinifera
  • Improved wine quality over labrusca
  • Active northern breeding programs
  • Improved potential for NE wines

Hardy Grape Varieties

Concord (Lubrusca) Types

(Click on thumbnails to view enlargements.)

Blue/Black: Table and Juice

  • Lubrusca-type grapesBeta
  • King of the North
  • Valiant
  • Bluebell
  • Fredonia
  • Worden

Beta, King of the North

  • King of the North grapesVery hardy
  • Early maturity
  • Small, blue/black fruit
  • Seeded
  • Juice, jelly, table

Valiant

  • Valiant grapesVery hardy (ripera cross)
  • Early maturity
  • Small, blue/black fruit
  • Seeded
  • Juice, jelly, table
  • Flavor only fair

Bluebell

  • Bluebell grapesVery hardy
  • Early-mid maturity
  • Medium, blue/black fruit
  • Seeded
  • Juice, jelly, table
  • Good flavor
  • Disease resistant

Fredonia

  • Fredonia grapesHardy
  • Mid-late maturity
  • Med-large blue/black
  • Seeded
  • Juice, jelly, table, wine?
  • Good flavor (Concord)

Candice

  • Candice grapesHardy?
  • Early-mid maturity
  • Small-med red/pink fruit
  • Seedless
  • Table, juice
  • Good flavor; v. sweet

Reliance

  • Reliance grapesHardy?
  • Early-mid maturity
  • Med. red/pink fruit
  • Seedless
  • Table, juice, wine?
  • Good flavor

Vanessa

  • Vanessa grapesHardy?
  • Early-mid maturity
  • Med. red fruit
  • Seedless
  • Table, juice, wine
  • Good flavor, texture

Somerset

  • Somerset grapesHardy
  • Early-mid maturity
  • Med. red fruit
  • Seedless
  • Table, juice, wine
  • Good flavor, texture
  • Disease resistant

Edelweiss

  • Edelweiss grapesHardy
  • Early-mid maturity
  • Med. white fruit
  • Seeded
  • Table, juice, wine
  • Good flavor, texture
  • Disease resistant

Hybrid Types

(Click on thumbnails to view enlargements.)

Frontenac, +Gris, +Blanc

  • Frontenac Gris and Blanc grapesVery Hardy
  • Mid-late maturity
  • Small, blue/black fruit
    • Amber (Gris)
    • White (Blanc)
  • Wine
  • Disease resistant

Marechal Foch

  • Marechal Foch grapesVery Hardy
  • Early-mid maturity
  • Small, blue/black fruit
  • Wine (blending)
  • Disease resistant

St. Croix

  • St. Croix grapesVery Hardy
  • Early-mid maturity
  • Small, blue/red fruit
  • Wine, table
  • Disease resistant

Sabrevois

  • Sabrevois grapesVery Hardy
  • Early-mid maturity
  • Small, blue/red fruit
  • Wine
  • Disease resistant

Marquette

  • Marquette grapesVery Hardy
  • Early-mid maturity
  • Small, blue/red fruit
  • Wine
  • Disease resistant

Kay Gray

  • Kay Gray grapesVery Hardy
  • Early-mid maturity
  • Med-Large, white fruit
  • Wine
  • Disease resistant

Prairie Star

  • Prairie Star grapesVery Hardy
  • Early-mid maturity
  • Medium, white fruit
  • Wine
  • Disease resistant

St. Pepin

  • St. Pepin grapesHardy
  • Early-mid maturity
  • Medium, white fruit
  • Wine (sweet)

DIY Grape Variety Trials

  • Test them yourself!
  • Talk to other growers
  • Always trial new varieties in small plantings (reduce risk)
  • Plant new varieties next to a standard for your area
  • Observe for at least two harvest seasons before “buying in”
  • Get customer feedback

Site Selection

row of grapevines wet, muddy soilExposure

  • Full Sunlight
  • Protected from wind
    • Windbreaks
  • Run rows North to South
  • 0 to 8% slope

Soils

  • Many types acceptable
    • Sand to silt, but not clay
  • Well-drained
  • High % organic matter
    • (4-6% or more)
  • Soil pH: 6.0 to 6.8
  • Take a soil test!

Site Preparation

man rototilling garden field of weedsSoil Test

  • pH, nutrients, o.m.

Soil Amendments

  • Lime, dolomite, sulfur
    • Modify pH to 6-7
  • Fertilizer (N-P-K)
  • Organic Matter
  • Compost, manure

Eliminate Weeds

  • Tillage
  • Herbicides
  • Pre-Plant Cover Crops
    • ↓ Weeds
    • ↑ Organic Matter
  • Fallow

Planting Grapes

  • newly planted vine row of staked grape vines, using grow tubesUse 1-year old plants
    • Bare root or potted
      • $5-10 ea.
      • 600 to 800/acre
  • Soak roots before planting
    • 1-3 hours (don’t drown them)
  • Plant at nursery depth
  • No fertilizer!
    • Add compost to backfill
  • Support stake
  • Prune to 1-2 shoots
  • Water in
  • Apply grow tubes?
    • 3.5” dia. x 30” height
  • Mulch: ↑ moisture, ↓ weeds
    • Woodchips, bark, plastic
  • Remove in fall
    • Sun & mouse damage
  • Spacing:
    • 8-10’ between plants
    • 8-14’ between rows
    • 600 to 800/acre
  • Use stakes or string to train shoot up to trellis wire (or grow tubes)

newly established grape vineEstablishing the Vineyard

  • Establish sod between rows
    • Fall prior to planting
      • Eases planting activities
      • May compete with vines
    • Fall after planting
      • No competition
      • Must control weeds
    • Use slow-growing lawn mix
      • Hard fescue/bluegrass

Trellising Grapes

  • Endposts
    • Set at least 2’ deep
    • Angle away from row 45º
    • Anchor with wire
  • Posts every 24’
  • Attach two trellis wires
    • At heights of 2.5’ and 5’
    • #9 galvanized wire
      • Adjustable tension

(Click on thumbnails to view enlargements.)


irrigated grapevinesIrrigation

  • Adequate water is critical!
    • Establishment
    • Fruit sizing, quality
  • Avoid watering foliage
    • Encourages disease
    • Wastes water
  • Trickle or drip systems best
    • Require less water & pressure
    • Require clean water
      • Filters

Training Grapes

Video: Caring for Young Grape Vines (YouTube)

Video: Four Arm Kniffin System for Growing Grapes (YouTube)

 

Trellis: 4-Arm Kniffin

  • Two Wires
  • Low wire, 3 feet
  • High wire, 5 feet

First Year:

  • Remove all but one strong cane
  • Cut remaining cane to 2 buds
  • Tie to stake for support

SecondThird Year:

  • Train trunk to the top wire
  • Remove all shoots between wires
  • Cut shoots on the low wire to two buds

Mature Vines

  • 4 to 6 canes (1-year-old)
    • 5 to 12 buds each
  • 4 to 6 renewal spurs
    • 2 buds each
  • Total 40-60 buds per plant

(Click on thumbnails to view enlargements.)

Training grapevines: 4-Arm Kniffin
4-Arm Kniffin

Video: Umbrella Kniffin System for Growing Grapes (YouTube)

First – Second Year:

  • Remove all but one strong cane
  • Cut remaining cane to two buds
  • Tie to stake for support

Second – Third Year:

  • Train trunk to the top wire
  • Remove all but two shoots at top of the trunk
  • Drape over top wire, secure to low wire

Mature Vines

  • 4 canes (1-year-old)
    • 10 to 12 buds each
  • 2 to 4 renewal spurs
    • two buds each
  • Total 40-50 buds per plant

Click on images to view enlargements.

Training grapvines: Umbrella Kniffin
Umbrella Kniffin

Illustration showing how to train tender varieties or for cold sites: Canes, R. spurs, Trunk, "Hinge"Tender Varieties & Cold Sites

  • Bend 1st-year shoot 90º for ~12”
  • Bend back up to form “hinge”
  • Use stakes & wire to train shoot
  • Pull plant off trellis in fall
    • Hinge allows trunk to bend
  • Cover with soil or mulch
  • Return to trellis in spring

Fan System or VSP (Vertical shoot positioning)

First – Second Year:

  • Remove all but one strong cane
  • Cut remaining cane to two buds

Second – Third Year:

  • Shorten two canes to 3-4 buds
    • Remove all others
  • Tie 2-4 canes to wires
    • Spread to fan pattern

Mature Vines

  • 4 to 6 canes (1-year-old)
    • 10 to 12 buds each
  • 2 to 4 renewal spurs
    • 2 buds each
  • Total 40-50 buds per plant

(Click on thumbnails to view enlargements.)


Growing Grapes

grapes growing on trellisesWalls, fences, arbors, etc.

  • Protected, full sunlight
  • Keep trunk, canes low
  • Lower and cover for winter
  • Prune to 40-60 buds/plant
    • 5-15 buds/cane
    • 4-15 canes or spurs/trunk

Pruning Grapes

pruning grapevinesDecember – March

  • When canes are fully dormant

Prune out

  • old canes (2+ years)
  • weak canes
  • injured\diseased
  • “bull wood” (> ½” thick)

Select 1-year old canes

  • 3/8” diameter
  • Chocolate brown
  • Healthy (green interior)

Retain 1-6 fruiting canes

  • 5-12 buds each

Retain 2-6 renewal spurs

  • two buds each

pruned grapevine showing healthy cane with 5-12 buds, renewal spur with 2 buds, abd the trunk


Fertilizing Grapes

  • Maintain pH at 6-7
  • Soil test every two-three years
  • Spring
    • Apply ~ 2oz. N, 1 oz. P & K
    • Or ½ lb. 10-6-4 per plant
    • ~20 lbs. N per Acre
  • Mid-June
    • Repeat application

Harvesting Grapes

ripe grapesLong Season Crop

  • 120-160 frost-free days
  • Color before ripe
  • Need to develop sweetness
    • Brix: 15-20+
  • Test by taste
    • Won’t improve postharvest
  • Yield 0-25 lbs. per plant
    • 0-4 tons/acre
    • 12 lbs. yields ~ 1 gal. juice

Grape Problems

Winter Injury

  • Dry, light brown or gray canes
    • No green within canes
    • No green within buds
  • Labrusca types
    • -15 to -20º: bud & cane injury
    • -25 or lower: trunk injury
  • Vinifera hybrids
    • 0 to -10º: bud & cane injury
    • -15 or lower: trunk injury

Weeds

  • weeds around grapevinesMost significant pest
  • Delay establishment
  • Reduce plant growth
  • Reduce yield and quality
  • Harbor insects and diseases
  • Management
    • Eliminate pre-plant
    • Cultivation
    • Mulch
    • Some hand-pulling will be necessary!

Diseases

  • Caused by fungi
  • Favor moist environment
  • Management Keys:
    • Good air circulation
    • Good pruning
    • Sanitation
    • Fungicides?

Black Rot

  • Management
    • Good air circulation
    • Good pruning
    • Sanitation
      • Remove mummies
    • Fungicides
      • Apply spring to ripening
        • Flint, Pristine, Ferbam
        • Copper

Botrytis Bunch Rot

  • Management
    • Good air circulation
    • Good pruning
    • Sanitation
      • Remove mummies, debris
    • Fungicides
      • Apply spring to ripening
        • Captan, Pristine, Elevate
        • Copper

Downy Mildew

  • Management
    • Good air circulation
    • Good pruning
    • Sanitation
      • Remove debris
    • Fungicides
      • Apply late spring to ripening
        • Prophyt®, Pristine®,
        • Copper, Sulfur*

Powdery Mildew

  • Management
    • Good air circulation
    • Good pruning
    • Sanitation
    • Fungicides
      • Apply at first sign of infection
        • Pristine, Sovran®, Flint®, Procure®
        • Copper, Sulfur*

Insects

Management Keys:

  • honey bee on flower
    Most insects are not pests!

    Keep plants healthy

  • Remove alternate hosts
    • Especially weeds

Management Options:

  • Hand picking
  • Predators/parasites
  • Sanitation
  • Insecticides

Japanese beetle

  • Japanese beetles on grape leaf Japanese beetle trapFeed on leaves, fruit

Management

  • Hand picking
  • Insecticides
    • Sevin®, Assail®
    • Neem, Surround®
  • Traps: ineffective
  • Grub control: ineffective

Leaf Hoppers

  • Feed on leaf underside

Management

  • Sanitation
    • Remove debris
  • Insecticides
    • Provado®, Assail®, Sevin®
    • JMS Stylet oil®

Phylloxera

  • galls on grape leaf caused by PhylloxeraCause galls on leaves
  • Usually not significant

Management

  • Remove infected leaves
  • Insecticides
    • Malathion, Sevin®

Spray Schedule

When Why What
Dormant Black Rot, Anthracnose Lime Sulfur
Bud Swell Flea Beetle Sevin®, Pyrethrum
New Growth ~4” long Black Rot Captan Fixed Copper
Post Bloom Black Rot Captan, Fixed Copper
Cover Sprays 10-14 day apart Black Rot, Botrytis Powdery Mildew Captan, Copper, Oil?
Whenever Japanese Beetle, Leafhopper Sevin® Pyrethrum

Spotted Wing Drosophila

Trap for Spotted Wing Drosophila
SWD Trap, photo by David Handley

Spotted Wing Drosophila

Symptoms:

  • Prematurely rotten fruit
  • Small, white maggots

Management

  • Traps for flies
  • Clean up all rotten fruit
  • Insecticides
    • At first sign of damage
    • Delegate

Birds

netting over grapevines to keep out birds

  • Netting
    • Best method
    • Costly
  • Visual deterrents
    • Scarecrows, owls, tape
    • Set up at ripening
    • Move often
    • Combine with noise

Herbicide (2,4-D) injury

  • Grapes very sensitive
  • Avoid lawn/brush herbicides
    • Spray & granular
  • Talk to your neighbor?

Maine Grapes: Bottom Line

grapes ripening on the vineHigh Risk Crop

  • High establishment costs
  • High labor demands
  • Winter injury likely
  • Challenging pest complex
  • Difficult to get high quality
  • Questionable market
  • 4 to 5 years to production
  • High establishment costs
    • 10,000-$15,000/A
  • High maintenance costs
    • $3000/year
    • Mostly labor
  • Returns can be variable
    • $0-1000 labrusca
    • $0-2000 hybrids

Optimistic View:

  • New hardy varieties
  • Global warming
  • Market for local produce
    • Specialty items
    • Wine, juice, jelly, vines
  • Fun to grow!

Good luck!


Grape Resources

Cold Climate Grape Production, University of Vermont, UVM Grapes: Horticulture