77 Days to Maturity.  Bi-Color Extra Tender 277A F1 Sweet Corn Seeds produce exceptionally sweet corn with outstanding flavor. Isolation is required to avoid cross pollination, and warm soil temperature of at least 65 degees is recommended.  Treated seed.  100 seeds per package. To extend your corn harvest, make successive plantings weekly up to mid-July, or plant varieties with differing maturity dates.Grows best in full sun (at least 6 hours of direct sun per day). Cultivate carefully to avoid damaging surface roots. Use USDA Hardiness Zone 3 - 11 as your guideline for the appropriate climate for this plant. Refined ears with 18 to 20 rows of bicolor kernels are produced on 6 to 6-1/2' plants that are tilled. The cylindrical, well-filled ears are covered with tight, medium green husks and attractive flag leaves. Eating quality is exceptional, with outstanding sweet flavor. Intermediate resistance to NCLB, SCLB, and Stewart's wilt. Isolation required.

Zea mays: Synergistic corn has 75% sugar enhanced kernels and 25% Supersweet kernels. It combines the exceptional tenderness and sweet corn flavor of SE/se varieties with the extra sweetness, extended shelf life and field-holding ability of sh2 varieties. For best results, isolate Synergistic corn from any other corn. For best germination, soil temperature should be at least 70°

 Vegetable Garden – Tips on Growing Sweet Corn From Seed

Sowing

• Corn Seed Depth: 1" (2.5cm)
• Germination soil temperature: 80º F (27ºC)
• Days to Germination: 4
• Sow indoors: Not recommended
• Sow outdoors: 1 week after last frost

Growing

• pH range: 6.0-7.0
• Growing soil temperature: 65-75º F (18-24ºC)
• Spacing in beds :8".
• Watering: Moderate early, then heavy from flowering to harvest.
• Light: Full sun
• Nutrient requirements: N= high, P=high, K=high
• Rotation considerations: Precede with nitrogen fixing cover crop
• Good Companions: Bush beans, beet, cabbage, cantaloupe, cucumber, pea, parsley, pumpkin, squash.
• Bad Companions: Tomato

Sweet Corn will need plenty of space for 2 reasons:

• One it is a heavy feeder, and it is primarily pollinated by wind. As the grains of pollen are shed by the tassels that grow from the plants' tops, they must first find their way to the delicate strands of silk that emerge from newly formed ears. To make sure that the silks are nicely showered with pollen, grow corn in blocks of short rows rather than in a long, single row. In a small garden, 15 plants set 1 foot apart can be grown in a 3 x 5-foot bed. Growing corn on this tiny scale is a good way to introduce yourself to the crop if you’ve never grown it. After the first year you will probably want to increase the size of the planting to at least 4 rows 10 feet long.
• Corn plants are not like tomatoes and most other vegetables that bear over a long period. Instead, they form a few ears per stalk and they are finished. Because of this, gardeners who have the space often make 2 or 3 plantings 2 weeks apart to keep the harvest coming.

Corn plants need a place in the garden that will get full sun and has fertile, well-drained soil with a pH of 6.0 to 6.8. Seedlings can be set out as soon as the last spring frost has passed. Space transplants of larger-growing varieties  8 to 12 inches apart. In case of a surprise late frost, be prepared to cover seedlings with a fabric row cover.

In cold climates you can plant in a raised bed covered with black plastic (infrared transmitting plastic) that will warm the soil. If possible, lay the plastic a week or so before planting. Plan to fertilize twice because corn is a hungry plant. Before setting out seedlings, amend the soil with compost and mix a balanced organic or timed-release fertilizer into the soil. About a cup of 10-10-10 per 10 feet of row is a good general rate, but trumps that with the rates given on the label of any fertilizer you are using. About 6 weeks or so later, when the plants start to produce tassels, fertilize them again. (If you amend the soil with cottonseed meal or other high-nitrogen amendment, it may not be necessary to feed the second time.) Use a hoe or trowel to mix the fertilizer into the top inch of soil between the plants. After this booster feeding, water your corn weekly if the weather is hot and dry.

Normal plants should grow fast with dark green healthy leaves. Corn will tell you if it is hungry by turning very light green. If so, feed again.

Corn grows fast and needs lots of water to grow properly. It also has shallow roots that make it susceptible to drought. Soaker hoses will insure that your corn gets the water it needs. However, for a large planting, soaker hoses may not be practical, in which case you will need a sprinkler or two with a large coverage area.

Native Americans in arid climates planted corn in basins to catch spring rainwater and help keep the corn roots down where water would be available longer. The basin was about 4 inches deep and 2 to 3 feet wide with a raised ridge made from the excavated soil around it. Plants were arranged so that they formed a spiral from the center to help with support in wind and with pollination. If you live in an arid climate or a hot climate and have poor sandy soil, as in the Coastal Plain, this technique could help insure a good harvest.

Most corn plants will yield at least 2 ears per stalk. Hybrids may yield more.

It can be hard to know when an ear of corn is ready to harvest because you can’t see inside the husk. Look at the silks. They should be brown and dry with just a little fresh green at the base. Squeeze the husk to see if the ear inside feels plump, not skinny. If the ear seems ripe, check by peeling just enough of the husk back to expose a couple of inches of the ear. Poke a kernel with your fingernail. The corn is ready to pick if it bleeds a light milky sap like skim milk. If the liquid is clear, the ear is not ready. Ears that are too ripe will look too milky, like cream versus skim milk; they often taste starchy. Of course, remove them, too.

Perfectly ripened ears also taste sugary-sweet when sampled raw. When possible, harvest sweet corn in the morning, when the ears are cool. To remove the ear, use one hand to hold the corn stalk and the other to pull the ear down and away from the stalk, twisting a little until it breaks off. Place harvested ears in the refrigerator right away. When kept chilled, ears will hold their sweet flavor for up to a week. Extra-sweet corn can be blanched and frozen, on or off the cob. Allow ears of grain corn to stay on the plants until the husks dry to tan. Gather them during a period of dry weather, and pull back the husks before using the ears as seasonal decorations. Remove all husks before storing dried ears for the winter in a cool, dry place. Corn plants that are blown over by gusty storms usually right themselves after a few days of sunny weather. As you shuck and clean your corn, pop off ear tips damaged by corn earworms. The different types of corn should not be allowed to cross-pollinate. That means that standard, open pollinated types, and super-sweet types need to be planted in such a way that pollen from one type does not reach another type. If you or a nearby neighbor grow multiple types, be sure that they are isolated by at least 250 feet or that their timing is such that they are not in bloom at the same time. If not, the pollen from types that are not the same can muddy their characteristics to the point of ruining sweetness and flavor.

USDA Hardiness Zone -First Frost Date- Last Frost Date

• Zone 1  -July 15th -June 15th
• Zone 2  -August 15th- May 15th
• Zone 3  -September 15th May 15th
• Zone 4  -September 15th May 15th
• Zone 5  -October 15th April 15th
• Zone 6  -October 15th April 15th
• Zone 7  -October 15th April 15th
• Zone 8  -November 15th March 15th
• Zone 9  -December 15th February 15th
• Zone 10 -December 15th January 31st (sometimes earlier)
• Zone 11 -No frost. No frost.

A Note about Isolation

• The reason for isolating super sweet(sh2) types is the same as isolating white from yellow corn, but more important because of how the ear of corn will be affected.  The sh2 types are isolated to prevent cross pollination with normal sugary sweet corn or field corn. Isolation is done by one of three methods.
• By maturity 10 days to tow weeks.
• By distance of 100-150 feet upwind.
• A barrier planting.

Growing Sweet Corn

Below you will find Gardening Rules in growing successful Sweet Corn

• Isolate: Separate small plantings of the basic three types of corn; super sweet, other types of sweet corn and pop/dry corn types by either one of the following: Distance of 25 feet for home gardening Distance of 100 feet  for acreage plantings OR BY
• Time:   Use 10-15 days in between for a planting date/ maturity date difference. If you do not use one of the above extensive crossing between types will result in tough, starchy kernels in the sweet corn.
• Soil Temperature: Monitor and delay any sowing fungicide or treated seeds until the soil temperature is at least 55ºF. Untreated seeds need a minimum soil temperature of 65ºF.
• Moisture:   Avoid dry soil at the time of planting, especially for the seeds of the super sweet type as this type needs twice the amount of moisture to germinate as other types of sweet corn.
• Fertilize:   Corn is a hungry plant, with high fertility requirement. Fertilize as required and use a high phosphate starter.
• Make sure your seed bed or area is smooth:   It is very important that you have uniform seed depth placement.
• Ideal Depth:    With an absolute soil moisture the ideal depth is ¾ to 1 inch to insure even emergence.
• Half Silk Date:   When tasseling has occurred watch and record the date on which about half of the plants show ear silk.
• Time to Harvest:    Your crop will be ready to pick beginning 18-24 days after Half Silk, depending of course on the temperatures during this period. Warmer weather favors earlier maturity. Allow kernels to get sufficiently plump for full flavor.
• Refrigerate:   As soon as you pick your corn it is very important to Hydro-cool the ears, by placing in ice cold water to remove the internal heat as well as the field heat. This will stop the change from sugar to carbohydrate. Then refrigerate at 32ºF.

Sweet Corn Types

• se and se+= Sugary Enhanced: 100% of kernels are sugar enhanced. Each tasty kernel has higher sugar content than the normal sugar types, but has comparable levels of starch which contribute to its creamy texture and delicious flavor. They too, should be isolated from field corn, popcorn, ornamental corn, and shrunken (sh) types. For best results isolate from Normal (su) sweet corn.
• sh2 = Super Sweet : 100% of kernels are super sweet, with 2-3 times the sugars of normal sugary types. The Supersweets as a class have a low seed density which results in higher seed counts/lb. Growers should wait for ideal soil conditions (soil temperatures of at least 60-65° F. and moist but not saturated soil) before planting. This class will also germinate better if not planted too deep. Depth should be determined by soil moisture level in the field. All supersweet corns can be planted with other supersweet corns, but should be isolated from all other genetic types to ensure their eating quality.
• su = Normal Sugar Type.Sugars convert to starch rapdily after harvest.
• se/sh2 = kernels are 75% of Sugar enhanced and 25% of Super Sweet.