FALL PLANTING - WHAT TO PLANT, WHEN, WHY
by Jerry Parsons, Ph.D.
Horticulture Specialist, Texas Agricultural Extension Service
in San Antonio
"Now is the time for all good gardeners
to arise, take up your hoe and strike a blow for fall vegetable
This beautiful quote above did not spring from
an intellectual philosopher-just from a mere Texas A&M
Extension vegetable specialist. The time is now, folks!
Why NOW? Common sense tells us that all vegetable
crops require a certain growing period before harvest can
occur. Experience tells us that certain vegetables require
a longer growing period than others to reach maturity.
For instance, vegetables such as beans, cucumbers,
okra, tomatoes, pepper, squash, beets, broccoli, cauliflower,
Swiss chard, collards, kohlrabi, lettuce, and spinach require
at least 2 months of growth before harvest can begin. Crops
such as cantaloupe, potatoes, black-eyed peas (Southern peas),
corn, eggplant, watermelon, Brussels sprouts, cabbage, carrots,
onions, parsley and rutabagas require a growing period of
at least 3 months before harvest can occur.
When you realize that the first 6 vegetable
crops listed in each of the above categories are warm season
vegetables which can be damaged or killed by frost, you quickly
understand the urgency of planting certain fall vegetables
now. Two months from today is October; 3 months from today
is November. Since the San Antonio area's first frost occurs
in late November, frost-susceptible crops should be planted
or transplanted as soon as possible to insure an adequate
harvest period before cold damage occurs.
Planting of the frost-tolerant crops listed
can, and should be, delayed until mid-August or September.
Why? When soil temperatures are still too hot, the resulting
poor seed germination is a real dilemma for fall vegetable
producers. Vegetable seeds have optimum soil temperatures
at which they will sprout and grow best, and if the soil temperatures
exceed the maximum high, they will not sprout at all!
The maximum soil temperature for seeds of cabbage,
broccoli, cauliflower, cucumber, corn, okra, cantaloupe, pumpkin,
squash, turnip, and watermelon is 105 degrees F. The optimum
soil temperature for this group is 90 degrees F.
Vegetable seeds such as snap beans, beets,
carrots, chard, eggplant, onion, pepper, radish, and tomato
have a maximum soil temperature of 95 degrees F. at which
they will germinate; they love 85 degrees F. The cool-soil
lovers which will not tolerate soil temperatures above 85
degrees F. but grow like weeds at 75 degrees F. include lima
beans, lettuce, parsley, parsnips, peas, and spinach.
What should all of this mean to the fall vegetable
gardener? Simple! With air temperature having been over 95
degrees F. for the last several months, soil temperatures
will certainly be over 100 degrees F. This means that gardeners
will have better success in germinating vegetable seeds in
the first category (105 degrees F.). Yet some of the vegetables
listed in the second category (maximum temperature of 95 degrees
F.) such as eggplant, pepper and tomato must be planted now.
The answer is simple--use transplants of these
crops. Healthy transplants of recommended varieties are now
available at local nurseries. Crops such as cucumber, okra,
cantaloupe, squash, turnips, and watermelon can be planted
by seeding directly into the garden area. Wait until later
this month or early September to plant seeds of the others.
Soil temperatures can be somewhat modified
by adding organic matter which will loosen the soil. Also
helpful: mulching and maintaining soil moisture. However,
as I indicated last spring, the majority of home gardeners
do not own one of the most important growing aids available--a
soil thermometer. If you plant seeds in the spring when soil
is too cold or in the fall when soil is too hot, the results
are the same--disaster! Choose crops carefully for fall planting.
Consider the length required to reach maturity, as well as
Average Dates for First Frosts
To estimate when planting should begin for
a particular area, you must know the average first frost date.
November 20 is the average first frost date for the area south
of a line from Del Rio to Uvalde, San Antonio, Austin and
Beaumont. North of this line will experience a first frost
date in late October. Gardeners south of a line from Eagle
Pass to Pearsall, Pleasanton and Victoria should enjoy frostless
days until early December.
Remember these are "average" first
frost dates for each region. "Average" means that
frost can occur earlier, but, hopefully, it will be much later.
With these frost dates in mind, a gardener can decide which
frost-susceptible vegetables to plant, when to plant and whether
to use transplants or seeds.
Fall vegetable crops are categorized as long-term
and short-term crops. Duration of these crops is dependent
upon when the first killing frost occurs and the cold tolerance
of the selected vegetables.
Plant long-term, frost-tolerant vegetables
together. Frost-tolerant vegetables include beets, broccoli,
Brussels sprouts, cabbage, carrots, cauliflower, chard, collards,
garlic, kale, lettuce, mustard, onions, parsley, spinach and
turnips. Group short-term, frost-susceptible vegetables together
so that they can be removed when they die after the first
frost. Frost-susceptible vegetables include beans, cantaloupes,
corn, cucumbers, eggplants, okra, peas, peppers, Irish potatoes,
sweet potatoes, squash, tomatoes and watermelons. (Planting
a cereal rye cover crop facilitates frost protection if such
a grouping system is used.)
Keep in mind the relative maturity rate, average
height and frost sensitivity of various garden vegetables.
FS crops (frost-susceptible) will die or be damaged by temperatures
below 32 degrees F. FT crops (frost-tolerant) can withstand
temperatures below 32 degrees F.
The quick (30-60 days) maturing vegetables
Beets (1 ½ feet) FT
Bush beans (1 ½ feet) FS
Leaf lettuce (1 foot) FT
Mustard (1 ½ feet) FT
Radishes (1 ½ feet) FT
Spinach (1 foot) FT
Summer squash (3 feet) FS
Turnips (1 ½ feet) FT
Turnip greens (1 ½ feet) FT
The moderate (60-80 days) maturing vegetables are:
Broccoli (3 feet) FT
Chinese cabbage (1 ½ feet) FT
Carrots (1 foot) FT
Cucumbers (1 foot) FS
Corn (6 feet) FS
Green onions (1 ½ feet) FT
Kohlrabi (1 ½ feet) FT
Lima bush beans (1 ½ feet) FS
Okra (6 feet) FS
Parsley (1 ½) FT
Peppers (3 feet) FS
Cherry tomatoes (4 feet) FS
The slow (80 days or more) maturing vegetables
Brussels sprouts (2 feet) FT
Bulb onions (1 ½ feet) FT
Cabbage (1 ½ feet) FT
Cantaloupes (1 foot) FS
Cauliflower (3 feet) FT
Eggplant (3 feet) FS
Garlic (1 foot) FT
Irish potatoes (2 feet) FS
Pumpkins (2 feet) FS
Sweet potatoes (2 feet) FS
Tomatoes (4 feet) FS
Watermelon (1 foot) FS
Winter squash (1 foot) FS
The dates found on the following website are
dates during which plants can be grown directly from seeds
sown in the garden area. If you decide to plant a certain
crop but it is too late to seed directly into the garden soil
in your specific region, then you should use transplants.
The dates will insure success only if you use the recommended,
fast-maturing varieties. The URL for this website is:
Fall Hybrids and Varieties
"We've come a long way, baby" could
be the slogan for vegetable producers in the San Antonio area.
Major advancements have been in the area of production reliability.
Reliable production has been made possible by new hybrid varieties
of vegetables that
are earlier producers of larger yields. These hybrids are
disease and nematode resistant, as well as vigorous growers.
They offer the best that can be.
For example, 25 years ago the tomato variety,
Homestead, was the most widely planted variety in this area.
Growers were pleased to be able to harvest 1 planting out
of 5 before the fall frost destroyed the plants loaded with
green tomatoes. Then, the Texas Agricultural Extension Service
introduced hybrids such as Spring Giant, and growers began
having a much better chance of fall tomato harvests. Other
tomato hybrids, such as Heatwave, SunMaster and Surefire,
are being harvested before the first fruit is being set on
a Homestead plant.
What is a "hybrid"? What makes it so special-- and
so expensive? A hybrid is the offspring of two plants of different
races, breeds, varieties or inbred lines of a particular crop.
Sweet corn offers an excellent example of how hybrids are
developed. Individual plants are selected from ordinary open?pollinated
(inbred) and the resulting seed from each plant is sown separately
the following year and selected plants are again self-pollinated.
This procedure is repeated for several generations until the
plants of each inbred line become very uniform. The inbreds
are then combined in various F-1 hybrid combinations and evaluated.
The hybrids which appear to be superior are tested extensively
and some may achieve commercial acceptance.
Because the development of hybrids and hybrid-seed
production entail extra work and expense, the hybrid crop
must have gained some advantage. One such advantage of most
hybrids is that they have greater vigor, i.e. a plant of greater
size, higher yield or earlier maturity.
Another important advantage of some hybrids
is greater uniformity. Most of the broccoli hybrids now being
grown are considerably more uniform in plant and head characteristics,
and especially in time of maturity than the open-pollinated
varieties they have replaced.
A disadvantage of hybrids is that the seed
is usually more expensive than that of true?breeding varieties.
This is primarily due to the special techniques necessary
in hybrid seed production. By one means or another, the pollen
of the seed-producing parent of a hybrid must be destroyed,
and pollen from the desired male parent must be allowed to
function instead. In commercial hybrid seed production, the
two parents of a hybrid are usually inter-planted in the same
field, and pollen producing flowers or flower parts are removed
by hand from the seed producing line. Obviously this requires
time and labor. Because of the seed expense, purchasing transplants
of hybrid vegetables enables a gardener to enjoy the benefits
of hybrid plants without the cost and care of producing hybrid
All hybrids are not good. The tomato hybrids
Heatwave, SunMaster and Surefire are well adapted to this
area, while and hybrids such as Big Boy and Beefsteak are
not, and therefore, in comparison, are not as productive.
The Texas Cooperative Extension continually tests new hybrids
to determine if they are adapted. Believe me, you can't base
a decision on claims made by the seed companies. According
to each company, their hybrid is the best! And it may be -
in Michigan - but not in Texas. Regardless, hybrids do offer
solutions to some serious problems with which Texas gardeners
have to contend.