Growing Grapes 3-5-10

Laguna Hills Nursery

 (949) 830-5653 

www.lagunahillsnursery.com

 

            Grapes are native to all continents in the Northern Hemisphere.  There are 2 types of major importance. 

The European grapes (Vitis vinifera) are most familiar.  Most commercial table and wine grapes are European.  Most European grape varieties perform better in inland Orange County where the summer is quite warm.  Within 15 miles of the coast they must be treated for Powdery Mildew disease. 

The American grape (Vitis lambrusca) originated in the Northeastern United States.  Most American grape varieties need little heat to perform and are resistant to Powdery Mildew disease.  Typical American grapes like Concord, have tougher skins and softer flesh. 

The hybrid grapes are American grapes that have been bred with other species (usually European).  Hybrid grapes often combine characteristics of both parents.  In coastal Orange County the recommended hybrids combine the mildew resistance of American grapes with the tender skin and crispy flesh of European grapes. 

We offer grapes grown on their own roots.  Many commercial vineyards acquire grafted plants that use a rootstock that is tolerant of Phylloxera (an insect that infects roots) however the University of California is not yet convinced of their value in areas where Phylloxera is not present and the rootstock does alter the flavor. 

 

 

Table Varieties:

Canadice (Hybrid) Seedless medium size, round berry with red blushed skin.  Rich vinious flavor of very good quality.  Good for table, juice, jelly, wine and raisins.

Concord (American)  Seeded large round berry with tough, black skin.  Juicy and sweet with an outstanding foxy flavor.  Ripens mid-summer.  Good for table, excellent for juice and jelly.  Performs well throughout Orange County.  Will produce good fruit with just a few hours of direct sunlight. 

Flame (European)  Seedless medium size berry with red skin and firm, crispy flesh of very good quality.  Good for table and raisins.  Ripens mid-summer.  More reliable when grown well away from the coast.  This is a very popular commercial variety.

Interlaken (Hybrid)  Seedless small, round berry with greenish-yellow skin.  The strong, sweet flavor combined with tender skin and crispy flesh makes this an outstanding variety and would be far more popular if the berries were larger. 

Lakemont (Hybrid)  Seedless, medium size fruit similar to Thompson Seedless (its parent) with a milder flavor.  Unlike Thompson Seedless this variety performs well locally with no mildew. 

Suffolk Red (Hybrid Russian/American)  Seedless, large berry with a bright red blush.  This has been the taste test winner of the Hybrid grapes.  So far we have seen no mildew.  This fairly new introduction is available in limited quantities. 

Venus (Hybrid)  Seedless medium size berry with nearly black skin.  The skin is slightly tough.  The clusters are unusually tight.  Incredibly productive even when grown in part sun.  Very good for table or wine.  HIGHLY RECOMMENDED. 

 

Wine Grapes:

Gary admittedly has little experience growing wine grapes.  When the variety performs best in cool summer climates we assume that it wants summer high temperatures that average below 85°F.  This is usually found within 10 miles of the coast or above 4000 foot elevation in the local mountains. 

Cabernet Sauvignon  Red wine.  Small, round seedy berry with black skin that ripens late.  Best in cool summer climates.  Except for susceptibility to Powdery Mildew disease it is relatively easy-to-grow.  Adaptable to most soils, but ripens earlier on gravely soils. 

Chardonnay  White burgundy wine and the most popular in California.  Small round berry that ripens early.  .  Best in cool summer climates.  Easy-to-grow and prefers clay, chalky or limestone soils. 

Merlot  Red wine.  Medium size, round berry with bluish-black skin.  Best in cool summer climates.  Prefers clay, chalky or limestone soils. 

Pinot Noir  Burgundy wine.  Small round berry with black skin in small pinecone-shaped clusters.  Best in cool summer climates.  Difficult to grow, susceptible to many diseases, but quite popular because of the quality of the wine. 

Shiraz (Syrah)  Red wine.  Large, long, loose bunches on a vigorous, disease resistant vine.  Prefers poor soil and hot climates.  The most popular wine grape in Australia. 

Zinfandel  Red wine.  Medium size, round berry with purple to black skin in large, tight bunches.  Ripens fairly early.  Vigorous vine.  Excellent for cool or warm climates. 

 

 

Location

            American & Hybrid grapes can be grown anywhere they can receive at least half sun.  A full day of sun will result in larger clusters and better flavor and sweetness, however I am continually amazed at the excellent production of many of these varieties under marginal conditions. 

European grapes have to be located where there is excellent air circulation, or where they can be easily treated for Powdery Mildew disease.  Give European grapes at least a half-day of sun, but most do best with a full day.  Many vineyards have a rose garden nearby because during the year roses tend to show symptoms of Powdery Mildew 2 weeks before the grapes are affected. 

 

Soil & Irrigation

            Grapes require a well-drained soil.  The soil type can be anything from gravel to clay, but drainage is a must.  As with any other plant we do not recommend incorporation of organic matter into the soil.  We do recommend mulching the surface with organic matter to provide insulation and nutrition.  Drainage can be improved by raising the planter and/or incorporation of pumice, perlite, decomposed granite or sand.  Raised beds are most beneficial.   

Grape plants prefer average to ample moisture.  Moisture stress during bloom can cause poor fruit set.  Lack of water will lead to undersize fruit.  Inconsistent watering can cause fruit to split.  Drip or trickle irrigation is widely used in California.  Keeping the leaves and fruit dry does prevent certain diseases. 

Wine grapes are often grown under mild moisture stress to produce smaller fruit with a higher sugar ratio and higher acidity.  This may be difficult to achieve in a home garden if plants in the surrounding areas require more irrigation. 

 

Fertilization

            Grapes do not require much fertilizer.  Excessive feeding results in rampant growth at the expense of fruit quality and quantity.  We recommend organic fertilizers.

 

Diseases

            Powdery Mildew can cause total crop failure on most European grapes but rarely affects American or Hybrid varieties.  Powdery mildew is a surface fungal infection that affects both foliage and fruit.  If not controlled the skin of the berries will crack before harvest.  Organic products include various horticultural oils and plant oils applied as a spray repeated weekly during mildew weather.  Mildew is promoted by our typical early-May through mid-July gloomy weather.  (Iceberg roses planted nearby will pick up Powdery Mildew in spring about 2 week before the grapes.)  Sulfur dust is also an effective treatment. 

            Pierce’s Disease is the most serious local disease that you may or may not encounter.  It was originally called Anaheim Disease after it destroyed the Anaheim Colony vineyards in the 1870’s.  Most European grapes are affected.  Some American and some hybrids have shown tolerance.  This bacterial infection is spread primarily by insects called sharpshooters.  So far I haven’t seen literature suggesting that pruning tools can cause infection, but I would think it possible.  The sharpshooter sucks sap out of the stem causing an infection that severely limits the flow of sap beyond that point.  The infection spreads quickly upwards and more slowly down the stem.  The foliage on the stem gets a scorched look.  Either the leaf’s edge or sections of the leaf turn yellow or red with scorched edges.  Any developing fruit shrivels and the following years the growth on the affected branch is underdeveloped or fails altogether. 

            Cutting off infected branches before the infection spreads is the only way to cure a grape plant.  Badly infected plants should be removed.  There is no treatment that can cure the infected portion.  Treating surrounding vegetation for Sharpshooter insects can help.  The main problem with Pierce’s Disease is that it can infect many plants other than grapes, but have no outward symptoms. 

 

Shaping the Vine

            Generally grapes are excellent producers and without any training will produce a bumper crop.  The reasons for training grapes are to limit the size of the vine, lower the cost of maintenance, improve the quality of the grape, and control the harvest period.  Around the World there are probably over a hundred named training methods.  Vineyards often use different systems for different varieties or different climates.  In inland areas foliage cover is essential for preventing sunburn on the fruit.  In coastal areas it is important to have less foliage cover for better air circulation.  The goal is to have the clusters of fruit covered by 1-1/2 layers of leaves.  If the production branches are covered too deeply there is insufficient light to get quality or sustain production.  Here I will list the most common methods.

  1. Heading  The grape plants are trained like little trees with no support system used.  For varieties like Zinfandel with low vigor, this is quite popular. 
  2. Single Fruit Zone  The grape plants are trained on wires so that the developing fruit forms a straight line running down the vine row.  This is by far the most popular design.  The vines can be trained straight up, allowed to hang straight down, or anything in between, so long as the bunches are hanging at the same height.
  3. Divided Fruit Zone  The grape plants are trained on wires so that the developing fruit forms two straight lines running down the vine row.  The fruit lines are in parallel rows (separated by at least 2 feet) either side by side or stacked vertically.  When the lines are stacked vertically, the bottom and top do not mature at the same time or with the exact same fruit character. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Illustrations have been reproduced with permission by The Fruit Growers News

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

On farms there is a set distance between rows (3-12 feet) and plants (3-8 feet).  In experiments the harvest volume went up as the distance between rows decreased, however, the spacing of plants along the row made little difference.  Of course small distances between rows makes maintenance more difficult.  The size of farm equipment usually dictates the distance between rows.  There are some vineyards that use overhead trellises that cover the entire plot.

            The table grapes in my own yard have no set design.  Four vines are growing on small trellises, one is on a wrought iron fence, and two others are on top of our patio lattice.  All produce more than we can eat. 

 

Winter Pruning 

Grapes produce fruit on branches growing off of year old wood.  This means you must save some of last year’s growth to have fruit this year.  Grapes will produce fruit without pruning.  Proper winter pruning will create a more uniform, high quality crop.  There are several ways of doing this.

  1. No Pruning  There are some vineyards that don’t prune at all except to skirt the vines to keep leaves off the ground.  Production is higher but quality suffers.  There are variations on this theme. 
  2. Spur Pruning  This is traditional for wine grapes.  Year old branches are cut back to 1-3 nodes depending on vigor.
  3. Cane Pruning This is traditional for table grapes.  Year old branches are cut back to 2-3 feet long. 

 

 

 

 

Outline

 

Grapes native to N hemisphere

1.                  European

2.                  American

3.                  Hybrids with American

 

Varieties recommended for coastal Orange County

 

Location

            Sun exposure

            Air circulation

            Rose Garden

 

Soil

            Well-drained clay to gravel

            Ample to average moisture highly important to table

            Carefully controlled moisture stress important to wine grapes

 

Fertilizer

 

Disease management

            Powdery Mildew-begin treatment 2 weeks after roses

            Pierce’s

 

Shaping the Vine

            Goals-highest production without losing too much quality

1.      Foliage cover 1-1.5 layers thick

2.      good air circulation

3.      ease of harvest and maintenance

4.      Sustainable production

Most common methods

1.      Heading

2.      single fruit zone

3.      divided fruit zone vertically or horizontally

Distance between rows 3-12’

Distance between plants 3-8’

Direction of the rows N-S, E-W, NE-SW, NW-SE

Winter pruning

1.      Spur

2.      Cane

3.      none

4.      alternate years

 

                 

 

Vitis vinifera

Native to around the Black Sea. 

 

Cultivated by man and brought to Mesopotamia by 6000 BC.  Hard evidence of cultivation and wine making around 3200 BC.

 

Established across the Mediterranean by 2000 BC.   Greeks created vineyards in Italy, Southern France, Sicily and Spain. 

 

Romans refined grape growing and wine making techniques.  Used them primarily as sweeteners. 

 

After collapse of Roman civilization 400 AD the church kept viticulture alive and refined wine making. 

 

Welch 1869 invented unfermented grape juice using pasteurization process.

 

1860 Vitis vinifera nearly disappeared due to Phylloxera on roots of vines in France.  They saved the industry by grafting the vines.  Phylloxera is native to Eastern North America where it harmlessly feeds on grape leaves of American grapes.  They saved European wine grapes by grafting onto American grape rootstock. 

 

California grows over 90% of US crop

 

Average production of table grapes 8-12 tons per acre (0.5 lbs per sq. ft.)

 

California crop average 6 million tons per year

50+% wine

36%  raisin

13% table