Growing Organic Heirloom Tomatoes: Old Challenges and New

Growing Organic Heirloom Tomatoes:
Old Challenges and New Opportunities
Jeanine M. Davis
Department of Horticultural Science
N.C. State University
Photos by J. Davis and staff unless noted otherwise
© Jeanine Davis, 2013
Definition of “Heirloom Tomato”
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Variety has been available for at least 50 years.
Seeds are passed on through generations.
Are open pollinated.
Have special characteristics, e.g., flavor, color,
shape, size, earliness.
Heirloom tomatoes
are in high demand
Chefs and consumers are
often willing to pay high
prices for them.
Prices last year ranged from
$2.00 to $6.00 per pound
retail.
Photo from: Matthews Farmers Market
People love heirloom tomatoes
because they:
• Are flavorful
• Are colorful
• Come in unusual
shapes and sizes
• Have fun, interesting
names
• Have nostalgic value
• Are novel
Photo from: Fine Gardening Magazine
So why don’t all vegetable growers
produce heirloom tomatoes?
•They tend to be
thin skinned.
•They crack and
burst.
•Most are not
uniform in shape
and size.
•As a result, they
don’t ship well.
Most heirloom tomatoes have little
or no disease resistance.
This makes them challenging for organic growers to
produce, especially in warm, humid areas.
They are labor intensive.
• Yields and
earliness are very
variety
dependent.
• Reliability in terms
of yield and
quality is often
much less than
with hybrids.
• There can be be
variability from
seed lot to seed
lot.
BUT, production of heirloom
tomatoes can be quite profitable.
4,350 plants/acre (24 inch spacing; 5 foot centers)
Red Brandywine produced 9.2 lb mkt fruit/plant
Retail price of $2.00 per pound
Potential gross return: $80,040 per acre
An Iowa State Univ. budget shows potential net
returns (at $1.75 per pound) of $547 per 400 sq. ft.
of bed space.
This is why we have been conducting studies on
organic heirloom tomatoes since 2003.
How do you grow organic
heirloom tomatoes?
Where summer rains or morning dew
are common, I recommend growing in
greenhouses or high-tunnels.
Provides the best protection from foliar
disease and fruit crack.
This won’t solve all problems, but usually
more successful than outdoor production.
• Is more
expensive than
field
production.
• Many growers
do some of
both.
Photo of Peregrine Farm by Debbie Roos
Follow basic recommendations for
organic greenhouse tomato
production
Photo of Lee Farm by Debbie Roos
Many growers want to produce
heirloom tomatoes outside.
Almost all heirloom tomatoes are
indeterminate varieties that need taller and
stronger support than the standard shortstake, Florida weave system can provide.
Most commonly
used and reliable
method is oldfashioned high
trellising
Position 7-8 feet long posts (2-3 inches in
diameter & not pressure treated) 15 feet
apart in the row.
• Space plants 8-12 inches apart in the row.
• Anchor plants by strings top & bottom.
• Train plants to single stem.
Black plastic mulch, or landscape fabric, and
drip irrigation help reduce disease and allow for
easy supplemental fertilization.
Short-High Stake System
Start out with standard (3-4 foot high) staked
system. Space plants 18-24 inches apart.
Add taller stakes (5-6 ft long), every other stake,
right before putting on last string on short stake.
In this system, plants need to be topped
when they reach the top of the stakes.
Photo from Tomatofest
• In both systems suckers
must be removed and
plants trained to the
strings once or twice a
week.
• If a main stem is broken
off, a sucker can be
trained to take its place.
There are hundreds of heirloom varieties to choose
from and we’ve grown dozens of them!
Brandywine
Stupice
Photos from: Appalachian Seeds, Tomato Bob, and Trade Winds Fruit
The three varieties that had the best yields and
consumer acceptance in our trials:
German Johnson
76 days
From VA and NC. Pinkred fruit are about 1 lb.
Plants are productive but
with little disease
resistance.
Cherokee Purple 85 days
Fruit ripen to a unique dark, dusky pink/purple.
Excellent flavor. Good resistance to Septoria.
Mr. Stripey 56 days
Huge crops of red fruits with yellow-orange stripes.
Rich, tangy flavor. A favorite for taste and color.
Brandywine is a perennial favorite, but there is a
lot of variability between seed sources and it
doesn’t rate that high in taste tests.
Photo from bonnieplants.com
Our tomato breeder, Randy Gardner began
developing “heirloom type” hybrids to deal
with some of these issues. His successor,
Dilip Panthee, has continued to develop
more of these.
Objectives: increased disease resistance,
less cracking, improved nutrition and
better shipping qualities while
maintaining flavor and other
characteristics consumers love.
Heirlooms
Heirloom-type hybrid
In 2009 we grew 20 varieties of tomatoes; 11 were
heirlooms and 9 were new heirloom-type hybrids
with late blight resistance.
These are some of the heirloom varieties we grew
Pink Brandywine
Black Plum
Cherokee Purple
Persimmon
Arkansas Traveler
Mr. Stripey
Akers West Virginia
Orange Banana
These are the heirloom-type hybrids we grew
NC 08130
NC 089
NC 085
NC 08126
NC 08224
NC 0694
NC 08128
NC 08144
NC 131L
The two heirloom-type hybrids, NC 08144 and NC
08224 showed superb disease resistance, gave high
yields of excellent quality fruit, and were the two top
rated varieties in the taste tests.
We grew heirlooms and several heirloom-type hybrids
in two organic systems, a conventional system, and an
untreated control.
Organic 1: Brandt Sporatec and Ecotec.
Organic 2: Serenade, copper, Dipel and Neem oil.
For three years, 2006-2008, yields from the organic
systems was as high or better than in the
conventional system.
Serenade
Eventually came up with a system using
Sporatec, Ecotec, and Saf-T-Side with Serenade,
Neem, Dipel, and copper.
In 2009, late blight came in very early and was quite
severe. This is an example of what many
commercial, certified organic farms in our area
experienced. This photo was taken on August 20.
In our trial, late blight was evident on only a few of the
most susceptible heirloom varieties on August 21.
Within a week, late blight had made rapid progress
through the field. Some of the heirloom varieties
succumbed very quickly, even with regular sprays.
But the heirloom-type hybrids with late blight resistance
continued to produce throughout the season.
By early October, this is what all the heirloom plots
looked like. The sprays delayed the progress of the
disease, but could not stop or control it.
But this is what the heirloom-type hybrids with late
blight resistance and the organic spray schedule
looked like!
Take home message:
• Heirloom tomatoes can be grown organically,
but they are vulnerable to foliar diseases and
cracking.
• Growing in a high-tunnel or greenhouse is the
best insurance for obtaining a healthy crop.
• We don’t have the perfect spray program yet,
but there are materials that will help.
• Growing in a staked system is easier, but yields
will probably be lower than on a trellis.
• The new heirloom-type hybrids have disease
resistance packages that are attractive to many
organic growers.
• Some of the new heirloom-type hybrids taste as
good, or better than, the favorite heirlooms.
Our breeder is also developing openpollinated heirloom-type tomatoes with late
blight resistance!
These studies were funded by the N.C. Tomato
Growers Association, U.S.D.A., and Brandt.