Tumbledown Farm .9 Acres (give or take an acre or two)

Introduction

If we did not eat it every day, perhaps we too would be amazed at the sight of an edible grass with "an ear as thick as a man's arm, to which grains [are] 'affixed by nature in a wondrous manner and in form and size like garden peas'." (Michael Pollan, The Omnivore's Dilemma: A Natural History of Four Meals, quoting Columbus, 1493)  The crop that Squanto taught the pilgrims how to plant in 1621 (and that was grown in the colony of Virginia in 1608) is still the best and most dependable native American crop for producing the most food from the least ground...except when it is used for fuel (ethanol) instead of food! 


The word "corn" is the generic English word for a grain of anything--wheat, oats, barley, even salt.  The term "corn" was eventually adopted and adapted more narrowly in American English to designate the native American plant "Indian corn" or "maize."  Zea mays is a native plant!  No wonder it grows so well on Tumbledown Farm!  

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Gene Logsdon calls corn "America's Amazing Maize" (see bibliography below).  That's because corn is both a feed for animals (the grain is fed to horses, cows, hogs, chickens, and rabbits; and the fodder can also be fed to all of these, as well as to sheep and goats).  People will eat corn too!  There's nothing better than sweet corn picked fresh and served less than thirty minutes after picking.  Or popcorn you grew yourself.  ...or even field corn buttered and roasted on the grill.  Not to mention cornbread, corn pudding, hominy, grits, tortillas, corn chips, corn flakes (and other forms of cereal), starch, sugar, corn syrup, corn oil, and...above all, whiskey.  King Corn can even heat your home and drive your car!  (OK, that's corn as a "commodity"; some of these, especially the whiskey, are not recommended home garden uses of corn.)

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[Photo: Grinding corn with a Porkert hand mill into corn meal for cornbread.]
Nothing beats steaming hot cornbread fresh from the oven with a fresh glass of buttermilk.

So, if corn is so great, how do you raise it in the garden?  Here's how I do it.  The first step, as usual, is to figure out what variety to sow and where to get the seed.  But before we get there, let's take a short look at the natural history of the plant.

Zea mays Gramineae.

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[Photo: Botanically speaking, corn (maize) is a native grass!  Here you see the tassel bending in the wind.]

Zea mays is a native of America.  It is a true grass, a warm-weather annual, though none of the wild grasses resemble it very closely.  It was being cultivated by Native American tribes when Columbus came to the Americas.  He brought some home to Europe and the rest, as they say, is history.  Corn was used in Native American myth, ritual, and religion--even being found in ancient burial sites in some parts of Peru and Mexico.  Botanically, since it is a grass, corn belongs together with timothy, wheat, and blue grass.  The fibrous roots spread several feet in every direction.  (Hence the need to stop cultivating between plants after the first month and to stop cultivating between rows after the corn reaches knee high and the tops begin to close over the rows.)  When the plant reaches knee high or taller, thick roots begin to grow visibly from the joints closest to the ground.  These are bracing or stabilizing roots to help the plant stay rooted in the wind.

My experience is that tall corn will always get blown down in heavy weather in the garden, especially single rows of corn.  (Larger fields in my observation do not tend to be flattened as much.)  Before I learned better, I tried to prevent this "problem" or to correct it after the fact, even going so far as to "stake" the garden corn like you would tomatoes!  Much better just to leave it on the ground.  In a day or two it will right itself and be stronger for the effort!

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[Photo:  Corn blown over by fierce rain storm.  It was standing tall again in about 36 hours.]

The height of corn plants varies (according to the variety sown) from 2 to 20 feet, but the usual height for corn is 5 to 10 feet.  Field corn is on average significantly taller than sweet corn.  The large size of the corn plant and the need to plant it in blocks of 4 or more rows (see below) rules it out as a plant for some home gardeners.  The flowers are monoecious (male and female parts are on different flowers" of the same plant; male part is the tassel at the top of the stalk, the silks on the ears are the visible female parts).  Pollination occurs by gravity and blowing of pollen from the tassel to the silks.  This method of pollination means: 1) that a lone corn plant (or lone row of corn) usually does poorly (too little pollen reaches the silks) and results in poorly formed ears with few fully developed kernels of corn and 2) that it is very difficult to maintain pure varieties, because pollen can be blown a considerable distance depending on the wind speed and physical barriers to the pollen (estimates vary: e.g., up to a mile in a 10mph wind, 400 yards, 200 rods).

Kinds of Maize, Varieties of Corn for Planting in the Garden

Corn is classified in various ways and varieties are usually distinguished in seed catalog descriptions by the following characteristics:

Open-Pollinated and Hybrid

1) Open-Pollinated Corn

Open-pollinated varieties grow true from seed ("true" = seedlings are very much similar to the parents). Open-pollinated varieties are sometimes called "standard" or heirloom varieties.  They are pollinated in an uncontrolled way, naturally (in the case of corn, by the wind), not by human intervention.  Seed can be saved to plant the following year, and may even keep for more than one season under  dry conditions.  These days, most varieties sold are hybrids, so the few examples of open-pollinated varieties are listed here according to sub-category and hybrids are listed more extensively under the classifications that follow this section.

Examples of Open-Pollinated Field Corn:  Boon County White (Shumway), Earthtones Dent or Earth Tones Dent (Ornamental, Johnny's, Shumway), Eureka Ensilage (Shumway), Goliath Silo (Ensilage Seed, Shumway), Green Oxacana Dent (Shumway), Hickory King (Shumway), Lancaster Sure Crop (Shumway), Longfellow (Flint), Minnesota 13 (Flint), Norfolk Market (Shumway), Nothstine Dent (Johnny's), Painted Mountain (Ornamental, Johnny's), Rainbow Flint, Reid's Yellow Dent (Shumway), Silver Mine (Shumway), and Silver King or Wisconsin No. 7 (Shumway), Tait's White Dent (Shumway), and Trucker's Favorite White or Yellow (Shumway)

Examples of Open-Pollinated Popcorn:  Calico (Shumway), Japanese White Hull-less (Shumway)

Examples of Open-Pollinated Sweet Corn:  Black Mexican (Shumway), Country Gentleman (Shumway), Double Standard (Johnny's), Golden Bantam (Shumway), Howling Mob (Shumway), Pencil Cob Corn (Shumway), Six Shooter (Shumway), Stowell's Evergreen (Shumway)

2)  Hybrid Corn

Hybrids are the result of controlled cross-pollination of parent plants that are genetically different.  Hybrid seeds do not usually produce "true" to type and it is therefore not advisable to save seed that results from a hybrid planting.  The seedlings differ too greatly from the parents.  Examples of hybrid varieties follow below.

Field Corn

Dent Corn (Field Corn; open-pollinated or hybrid)

Dent Corn has traditionally been used mainly for animal feed and corn meal.  However, the commodity market now makes everything from ethanol and plastic to food processing agents from dent (field) corn. Examples: Best O' Show 722 (Shumway), E-Z-Pik 355 (Shumway), Hybrid Goliath Silo (Shumway), Vigor Root 550 (Shumway), XTRA Early 330 (Shumway)

Flint Corn (Ornamental Corn or Indian Corn; open-pollinated)

Flint corn is often multicolored (hence "ornamental"; some dent corns are also multicolored).  Some flint corns can also be used for corn meal and for animal feed.  Most mature in 90 days or less and are therefore more suited to northern planting.  Examples: Fiesta (Johnny's),   

Popcorn (open-pollinated or hybrid)

Popcorn is usually consumed as a low-calorie snack (low-calorie, that is, until you pour on the butter). Examples:  Giant Yellow Hybrid Type (Shumway), Robust 128YH (Johnny's), Snow Puff White Hybrid (Shumway)

Sweet Corn (white, yellow, and bicolor; open-pollinated or hybrid)

Sweet Corn is the garden favorite, because, well, "It tastes sweet!"  It tastes like sugar!  Sweet Corn comes with a confusing alphabet soup of genetic designations related to the sugar content of the kernels, time from picking to conversion of sugars into starches, and tenderness of kernels:

(su)

"Normal" sugary: moderate sugar content, quickly converts to starch after picking.  Examples: Earlivee (Shumway), Silver Queen (Johnny's, Shumway)

(se) and (se+)

Sugary enhanced (se) and fully sugary enhanced (se+):  a genetic variant that when present with (su) increases tenderness and sweetness and delays the conversion of sugar to starch after picking.  Examples: Ambrosia (se+, Shumway), Argent (se+, Shumway), Augusta (se+, Johnny's), Bodacious (se+, Shumway), Brocade (se+, Johnny's), Colorow (se+, Johnny's), Delectable (se or se+, Johnny's, Shumway), Fleet (se+, Johnny's), Luscious (se+, Johnny's), Mystique (se+, Johnny's), Seneca Dancer (se+, Johnny's), Silver Princess (Shumway), Spring Treat (Johnny's), Sugar Buns (se+, Johnny's), Sugar Pearl (se+, Johnny's), Trinity (se+, Johnny's), Whiteout (se+, Johnny's).

(sh2)

Shrunken (sh2): commonly also called supersweet; the "shrunken" name comes from the look of the dried kernel.  Grown by itself, this type offers sweet kernels and slow conversion to starch; but when cross-pollination occurs with any of the other types, the result is tough, starchy disaster.  Examples: Butter and Sugar (Shumway), Florida Stay Sweet (Shumway), Frosty (Shumway), How Sweet it Is (Shumway), Illinichief XTRA Sweet (Shumway), NK199 (Shumway), Northern XTRA Sweet (Shumway), Radiance (Shumway), Silver Queen (Shumway), Super Sweet Jubilee (Shumway), Vision (Johnny's), XTRA-Tender 270A (Johnny's), XTRA-Tender 272A (Johnny's), XTRA-Tender 275A (Johnny's), XTRA-Tender 277A (Johnny's, Shumway), XTRA-Tender 374A (Johnny's), XTRA-Tender 378A (Johnny's),

synergistic

"Synergistic" is a combination of 75% (se) and 25% (sh2) kernels on the same cob.  Examples: Frisky (Johnny's), Honey Select (Shumway), Montauk (Johnny's), Polka (Johnny's), Serendipity (Shumway).

Baby Corn  

Seen on salad bars and in Chinese restaurants for salads, pickling and stir fry.  Actually an example of (sh2) sweet corn.  Shumway offers a hybrid variety especially for picking 2"-4" cobs immediately when silks emerge.

Where to buy Corn (Maize) Seed:

All of the major mail order companies offer a large selection of sweet corn varieties for the home gardener.  It is somewhat harder to find dent (field) corn in the appropriate quantity for the micro-farmer.  However, several great seed catalogs still offer packets of field corn in multiple sizes.  The varieties listed above come from my two favorite "corn" seed sources, Johnny's Seeds and R.H. Shumway's.  For these and other catalogs that carry corn seed, see the Tumbledown Farm Organic Gardening Links page for additional links.

How to Do a Seed Corn Germination Test

It is important to know whether your seed is good before you plant it, especially if you are saving your own seed from an open-pollinated variety and not buying replacement seed every year from a reputable seed dealer.  (And if you are not able to plant a thick stand to thin later, as I do.)  Here's a simple seed germination test using an old sock, a method that was suggested to me by a farmer friend:

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Here I've taken 50 kernels each of seed saved from two different varieties (Reid's Yellow Dent and Hopi Blue Dent).

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Lay the seed out on the sock in rows.

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Roll the sock up and secure it with rubber bands.  Wet the sock thoroughly and keep it damp for the average germination period for corn (1-2 weeks is plenty).

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Unroll the sock carefully and count the germinated kernels.  In this case, 90% of the Reid's Yellow Dent and 94% of the Hopi Blue Dent germinated.  Ideally, germination should be 95%-100%.  You do not want 1 acre in 10 failing altogether!  (But if you plant thick, then thin the stand, you'll not have to worry even with these germination rates.)  The old timers had far more complicated and precise seed corn germination tests, including the use of numbered ears and a germination box (see, for example Wilson and Warburton, pp.  66-70).

Planting Corn:

When to Plant Corn

Corn is a tropical plant that cannot abide a frost, however light.  It will not germinate if the ground is cold.  The ground should be at least 60º F or warmer for planting.  (Black plastic over the germinating seed can help keep the soil warm enough for germination in a cold snap.)  Shumway recommends getting a quicker start in cold soils by soaking seeds in distilled water at 77º F for 16 hours, then drying at room temperature (70º?) for 8 hours, then planting immediately.  Corn does not transplant well, but it can be transplanted if done with care (e.g., in peat pots to avoid disturbing the roots).  Gene Logsdon recommends waiting to plant corn until a little later in the season: 1) so that you can get a greater benefit by tilling under more organic matter (corn is a heavy feeder on nutrients; you need the greater fertility that can be obtained by letting the cover crop grow a little longer) and 2) so that the likelihood of drier weather will allow for better mechanical cultivation (a hoe in my case) to keep the weeds down (again, corn is a heavy feeder and weeds are competition for limited nutrients).

From Corn

[Corn emerging from relatively late planting on wet ground after tilling under a cover crop.]

Seeding Rate: How much Corn (Maize) to Plant

Field Corn:  15,000-18,000 kernels per acre.  8"-9" between stalks in a row and 40" rows.  (Spaced for mechanical/field cultivation.)  12-15 inches between stalks if you plan to plant climbing beans between the plants in the row.  You can plant climbing beans between the corn plants when they reach about 6" tall.

Sweet Corn (and Popcorn and Ornamental): 6"-8" between stalks in a row and 30" rows.  (Spaced for hoeing or other hand cultivation.)

I generally plant corn much thicker than the rate recommended above (1 seed per inch) and then I thin ruthlessly as the corn grows and the leaves on the stalks begin to touch.  I keep thinning until I reach the recommended spacing.  I feed the stalks that I thin out to the rabbits.  (This seems to be their favorite early season garden treat!)

The general rule of thumb is to plant in "blocks" of four rows or more for proper pollination.  Any less and you'll have to do some hand pollinating to get full ears of corn.

You'll want enough sweet corn for eating fresh while it is in season (10-15 plants per person, more or less) and more for freezing.

Hand planting (dropping the seeds into a shallow furrow made by the corner of your hoe and covering the seed with a hoe or rake or by hand) can work for up to a quarter-acre, but once you get beyond that you'll want to invest in a hand-pushed planter or garden seeder.



Shumway and Johnny's also offer the Garden Seeder, as do other seed companies.

Seeding Depth: How Deep to Plant Corn (Maize)

The rule of thumb is the dryer the weather, the deeper you plant (to a point).  Start at about 1.5" for sweet corn and 2" for field corn, if there is plenty of moisture.  When the weather is dryer and warmer, plant deeper.  Maximum depth is about 3" to 4".

Cultivating Corn

Weeds compete for both moisture and nutrients with corn, so cultivate frequently until the corn is about knee high.  ("Corn should be 'knee high by the Fourth of July" is the adage in this part of Indiana.)  Stop cultivating at knee high because (with the row spacing recommended above) the roots have spread out beneath the rows.  You do not want to harm the roots.

From Corn

[Corn nearly knee high after recent cultivation between the rows with a hoe.]

Harvesting Corn

Harvesting is different for Sweet Corn than for Field Corn and the other types.

Harvesting Sweet Corn

Harvest Sweet Corn when kernels are "full" and "milky," that is, when they seem large and about to burst with a whitish fluid.  You can usually depend on the silks as a guide.  When the silks turn dry and brown, the corn is generally ready.  Another rule of thumb is to wait 18-24 days after you see the first silks appear.

Harvesting Field Corn (Dent, Flint, Ornamental and Popcorn)

Normally field corn (and the other types noted) are left out for several frosts, but the ears may be picked any time after the husks dry.  Husked ears can be kept in a dry place under cover, traditionally in a covered corn crib, to complete their "curing" (drying).  Traditionally a "corn knife" might be used to cut the stalks, which were then stacked (with the ears still attached) and tied together in shocks to be stored over winter.  This is especially effective for feeding to livestock (stalk, leaves, ear, husk and all).  Popcorn is especially sensitive to moisture and must be thoroughly dried where air can circulate around the ears for good popping.

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[An ear of Reid's Yellow Dent Open-Pollinated corn husked and ready for use.]
 

If you are planning to harvest and husk a large quantity of field corn, you'll want a to use a corn husker (husking pegs) and sheller!

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[Photo: Corn Husker (husking pegs)]

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[Photo: Corn Sheller]

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Corn Pests and Diseases:

I generally haven't had problems with pests and diseases.  The biggest pest problem has been how to keep racoons out of the sweet corn.  They always harvest the corn before I do and so I've mostly given up growing sweet corn.  The losses might be manageable in an area where I could grow more corn and where the racoons were fewer, but the ratio here in the suburbs of racoons to sweet corn is too high.  (They'll also attack field corn, but not as much.)  

Insects

Borers and Earworms

The best known of the insect pests are the borers and earworms.  If you aren't squeemish about the occasional worm in an ear of corn, the best method of control is to remove the pointy top of the ear right as you desilk sweet corn.  Ignore them altogether in field corn.  You usually will not lose enough corn to make it worth while (in time or money) to try to control them.

Rootworms

If you have a proper rotation, you shouldn't have any problems with this pest.

Wireworms

Cultivation is your best bet and replanting a new row next to the one that was attacked.

Birds

Birds attack the seed when first sown.  There is little to be done about it other than plant coated seed.  They'll eat some of the harvested field corn too if they can get at it.

Racoons

A terrible pest for sweet corn.  I'm not sure what can be done about them.  They cannot be shot in the suburbs.  Trapping and removing them seems too big a pain.

Diseases

There are various blights, wilts, spots, mosaics, and rots that will attack corn, but I've never suffered a significant loss from any of them.  Planting resistant varieties may help.  

Water and Temperature Requirements for Growing Corn

Corn is not recommended for areas that receive less than 25 inches of precipitation annually.  18 to 20 inches or more of precipitation is ideal for the growing season.  Corn can mature between 85 and 150 days, depending on variety, temperature, rainfall, and the like.  Optimal seasonal average temperatures are 68ºF - 73º F.   (See the National Corn Handbook from Purdue Extension.)

Nutrients and pH for Growing Corn

(Best bet in all cases is to get a soil test before creating a program of soil amendments and to test regularly every three years or so to check the effect your changes in rotation, cultivation, and soil amendments are having.) 

Corn is a heavy feeder on soil nutrients, especially nitrogen.  That means corn should be planted in a rotation that includes a legume (beans or clover, especially alfalfa).  Corn should follow the legume immediately in the rotation to take best advantage of the additional nitrogen provided by the legume.  Soil fertility can be maintained if all of the plant residues are tilled back into the soil, either directly or in the form of animal bedding and manure.

Maintain pH 6.0-6.5 by liming when the pH in the zone of sampling falls 0.2 to 0.3 pH units below the recommended level.  (See Purdue extension corn fertilizer publication AY-9-32 for more information, and for the chemical fertilizer approach outlined below.)  The subsoil at Tumbledown farm is not acid (pH is high), so there is no need for liming.  

Maintaining Soil Fertility for Corn: Traditional Approach

Logsdon recommends a green manure crop (grown for the purpose of plowing the whole crop under) every fourth year, 5-10 tons of manure per acre annually, half a ton of lime per acre as needed (to maintain appropriate pH), two tons of rock phosphate per acre as needed, and an application of potash rock or greensand as needed.  These together with the legume, according to Logsdon, should provide an "adequate" crop.  (Average yield at the turn of the century was about 40 bushels per acre.  But there were many instances of good ground well managed that yielded nearly a hundred bushels per acre.  Wilson and Warburton (see bibliography) recommend the application of no more than "ten to fifteen loads" of manure per acre.  Using Logsdon's recommendation as a guide, I'm guessing that a horse-drawn wagon "load" was probably a half ton of manure.  Wilson and Warburton also recommend the application of phosphorus and potash in the form of commercial fertilizers in addition to manure and green manure crops in the South and East, but indicate that commercial fertilizers usually aren't profitable in the corn belt.  Where useful, they recommend cotton-seed meal, muriate of potash, and acid phosphate (300-500 pounds in two applications; a fertilizer today with an analysis of 5-5-5 would easily meet their recommended fertilizing rate).

Maintaining Soil Fertility for Corn: Chemical Fertilizer Approach

If an "adequate" crop is inadequate for some reason--in other words, if you want to nearly double your corn production by direct chemical applications--you'll have to resort to some concentrated chemical form of Nitrogen fertilizer: e.g., anhydrous ammonia, urea, ammonium sulfate, or ammonium nitrate.  Anhydrous ammonia requires specialized equipment to handle and apply and is hazardous to handle.  Urea converts in less than two weeks to nitrate N.  Loss of N can then occur through denitrification (loss of nitrogen through breakdown of the nitrate), leaching, and volatization.  Ammonium sulfate suffers little or no loss from surface volatilization, but it increases the acidity of the soil.   Ammonium nitrate suffers leaching and denitrification.  In other words, expect to pay a lot (and to let loose a lot of N by volatization and leaching) to obtain your higher yields.  Be sure to consider the environmental costs, along with the actual money costs before deciding that 100 bushels an acre is inadequate.

Corn in a Garden Crop Rotation

The following chart is adapted from Logsdon's book (see bibliography).  I have used this six-year rotation in the past (and still use a similar one for strawberries), but my vegetable garden plan now calls for a four-year rotation which will rarely include corn.

1st Year	Plant Corn (spring); sow red clover [or rye] between the rows at last cultivation (corn about knee high)
2nd Year	Plow under clover [or rye] and plant peas (spring); plant cole vegetables (fall)
3rd Year	Tomatoes
4th Year	Beans (spring/summer); sow winter wheat (fall)
5th Year	Wheat (harvest in June); sow with clover in spring (at last freeze)
6th Year	Clover plowed under; plant corn (spring); sow red clover [or rye] between the rows at last cultivation (corn about knee high)

How to Cook Corn

There are more ways to cook corn than there are corn varieties--too many to count!  My favorites are to drop sweet corn freshly picked (minus the husk and silks) into a pot of boiling water for a few minutes and then smother it with butter and salt and pepper to taste.

In order to be used for human consumption, field corn must undergo an additional step of preparation.  I grind my field corn into corn meal using a Porkert hand mill (kitchen mill; see photo above).

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[Photo: Sifting Corn Meal]

Mama Glover's Southern Style Buttermilk Cornbread Recipe:

1 cup of ground cornmeal (above)
1 Tbsp of oil (olive oil or any vegetable oil; or the drippings from fried bacon)
1 Tbsp of baking powder
1/2 teaspoon of salt
1 egg
3/4 cup of buttermilk

1.  Preheat oven to 450º F
2.  Put oil in 10" or larger iron skillet and place in oven until hot (a drop of water will sizzle on surface)
3.  In a bowl mix cornmeal with baking powder and salt; add egg and buttermilk; mix (stir with a fork or whisk until the mixture is the consistency of pancake batter)
4.  Retrieve skillet and pour 1/2 oil (most of the excess oil) into the batter (stir it in)
5.  Pour batter from bowl into well-oiled, hot skillet
6.  Place in oven and bake 15 minutes at 450º F.

Corn (Maize) Bibliography:

Corn Fertilizer Publication, Purdue Extension.
King Corn, the Purdue Department of Agronomy website and Corn Growers' Guidebook.
National Corn Handbook, Climate and Weather.  Purdue Extension.
Logsdon, Gene. Small-Scale Grain Raising, pp. 10-64.
Sweet Corn, Purdue Extension Publication HO-98.
Rodale's All-New Encyclopedia of Organic Gardening. "Corn," pp. 149-151.
Wilson, A.D. and G.W. Warburton, Field Crops, pp. 47-134.