Hemp Seed Project for 4-H Clubs

Leaflet 25
University of Kentucky
College of Agriculture and Home Economics Agriculture Extension Service
Thomas P. Cooper, Dean and Director Lexington, Kentucky
March, 1943

Uncle Sam has asked Kentucky to produce in 1943 the hemp seed for the nation. Some of the seed will be used in 1944 to grow another seed crop, but most of it will be used to grow hemp for fiber. Growing hemp gives 4-H Club members a real opportunity to serve their country in wartime. It requires a small amount of fertile land and little or no special machinery; labor requirements do not interfere with school work. Grow at least half an acre of hemp; one to two acres would be better. Land that will produce 50 or more bushels of corn per acre will make 12 to 15 bushels of hemp seed per acre. Club members know how to tackle a new task; try this one.

Select fertile soil.
Select an old feedlot, an old garden spot, or any other fertile area. Better yields are obtained on well-drained bottom soil, but good yields are obtained on productive upland. Only land capable of growing good burley tobacco or 50 to 60 bushels of corn an acre, should be selected. Good drainage is essential.

Use plenty of fertilizer.--Use complete fertilizer on most soils. Apply 200 to 400 pounds of 4-12-8, 4-10-6 or similar analysis, at the hill. If applied broadcast, use 400 to 600 pounds an acre. For soils outside the Bluegrass area, use in addition 200 to 300 pounds of 20 per cent superphosphate broadcast. Stable manure is an excellent fertilizer for hemp.

Prepare seedbed carefully.--Plow in late winter or as early as possible. Disk and drag at once. Pulverize all clods. Immediately before planting, smooth the ground with a light drag or roller, or better still, with a cultipacker. A well-prepared seedbed is essential in getting a stand. Buy your seed.--About 1 1/2 to 2 pounds of seed will plant an acre. Purchase extra seed as it is often necessary to plant the crop over. Plant by hand.--Plant by hand in hills spaced 4 1/2 to 5 1/2 feet apart. Check for two way cultivation. Use the wider spacing for rich bottom land, the closer for upland. Mark off the field with a light sled marker so that the furrows will be shallow. Drop 12 to 15 seeds at each furrow crossing, spreading them out slightly to make thinning the plants easier.

Cover with the foot, pressing the soil down firmly. Unless the soil is quite dry, cover not more than 1 inch. Deep-planted seeds may not germinate, especially if a heavy rain occurs after planting. It is very important to press the soil firmly over the seeds, for they sprout soon and unless the soil over them is solid and compact it will dry out very quickly and the sprouted seeds will die. Getting a stand is one of the biggest problems in growing hemp, therefore plant the seeds with the greatest care. Thin and transplant, or plant over to get proper stand.---Most of the hemp seed is produced on the branches of the plant. When too many plants are in a hill, branches form only near the top of the plant and produce a low yield of seed. With hills spaced 4 1/2 feet apart, there should be 2 to 3 plants per hill on very productive bottom land; 3 to 4 plants on upland. If the spacing is 5 to 5 1/2 feet, there should be 3 plants per hill on bottom land; 3 to 4 on fertile upland. The more productive the soil, the fewer the plants per hill.

If plenty of plants come up in at least three-fourths of the hills, fill out the missing hills by transplanting from other hills with too many plants in them. Follow the method used in transplanting tobacco or tomatoes. Transplanting should be done when the soil is moist, after a rain. If the stand is too poor to be filled out in this way, rework the ground and plant a second time.

As 12 to 15 seeds are planted to the hill it is always necessary to thin out some of the hills. A good time to do this is after a light rain when the plants are large enough to get hold of easily with the fingers--about 8 to 10 inches tall. Roots of larger plants become matted and it is difficult to pull out one of them without injuring the others. As in thinning corn, thinning hemp is best done when the ground is fairly moist. If the plants are a foot or more high, either wait for a rain before thinning, or cut out the plants instead of pulling them.

Cultivate same as corn.--Hemp requires about the same cultivation as corn. Cultivate the crop both ways as soon as the plants are 2 to 4 inches high, even if it is impractical to get close to the hills. Hemp grows so fast that it usually chokes out the weeds in the hills. Use a riding cultivator equipped with good fenders. Because the rows are so far apart, run through the middles with a one-horse cultivator. Discontinue row cultivation after the plants are about 2 1/2 feet high, but cultivate the middles somewhat longer in order to keep down weeds.

Cut out the male plants.--Hemp produces both male and female plants. Because flowers on the female plant produce no pollen they must be fertilized by pollen from the male plants in order to make seed. After the pollen is shed and the male plants begin to die cut them out to give the female plants more room to develop. Male plants interfere seriously with harvesting because the hard strokes necessary to cut the male plants will shatter seed from the seed plants.

Harvest after the seed begins to shatter.--Hemp plants do not ripen uniformly. The date of maturity of plants in the same field varies from 2 to 3 weeks. For this reason it is difficult to determine when the crop should be cut. But these are the signs that it is ready to cut: plants have dropped the large leaves; branches have yellowed; red spots or streaks have appeared on the bark; the clump of small leaves and shuck around the seed have turned brown; and seed on the middle branches have begun to shatter. Examine plants closely every few days after mid-September to determine when to harvest. In cutting, use a strong, heavy corn knife. Be sure the knife is sharp enough to cut the plant with one stroke. Avoid jarring the stalk as the seed of ripe hemp shatters easily. Cut the plant a few inches below the lower branches.

Make strong shocks.--Select 3 or 4 strong plants, one from each of 3 or 4 hills, to make a support for the shock, as in shocking corn. Remove the branches from these plants. Bend them toward each other and tie their tops together. Make a bundle of the branches which have been cut off and place it on top of the support. Put 50 to 100 hills into each shock, depending upon the height and size of the plants. Shocked seed hemp is easily blown down; therefore great care should be taken in shocking. Spread out the base of the shock, draw in tight near top and tie. Bind the shocks above the center with two hemp stalks to prevent their blowing down. Two or 3 days later re-tie the shock to strengthen it and also to help it retain shattered seed. Place shocks about 24 feet from each other.

Thresh as soon as dry.--Handle ripe hemp gently to avoid shattering the seed. From 8 to 10 days after cutting or as soon as the seeds are thoroughly dry, begin threshing and finish it as soon as possible. Prompt threshing prevents heavy loss by shattering if the shocks are blown over; it also prevents damaged seeds if the rainy season sets in; and the heavy toll which birds sometimes take if the shocks stand very long.

Do not attempt threshing when the hemp is damp, either from rain or dew. Hemp comes in case each night and in fair weather dries out by noon. Therefore start threshing at noon and continue into the afternoon as long as the hemp is dry.

Spread the threshing canvas (21" x 21") on the ground between the shocks. Cut the stalks used to support the shock. With a man on each side of the shock and one at the back, push it over quickly so that the shattered seed in the top of the shock will fall on the canvas rather than on the ground. To thresh the seed, beat the stalks with clubs about 1 1/2 to 2 inches in diameter and 6 feet long. Turn the stalks frequently with the aid of the clubs and beat until they are free of seed. Then remove the threshed stalks from the canvas and repeat the process with the other shocks.

Clean Seed Before Marketing

Leaves, pieces of branches, dirt, and so on must be removed from the seed before it is marketed. Two steps are necessary; screening and fanning. You may screen and fan at one operation by using a combine or thresher, but generally for small crops you rub the seed through a "podder" or screen to remove the coarse material. Separate the fine material from the seed with a fanning mill. Directions for making a podder or cleaning screen, and for using the fanning mill may be obtained from your county agent or local leader.

Market Seed as Soon as it is Cleaned

Deliver the seed to established receiving points as soon as cleaned. The receiving points will be announced in the fall before the seed is ready for delivery, by your county agent.

TIME SCHEDULE FOR HEMP-SEED PROJECT

January-- Select well-drained, fertile land for the crop.
February- Apply stable manure.
March-- Work soil thoroughly. Apply phosphate broadcast and work it into soil.
April-- Get a permit for growing hemp. Get seed for planting.
May Work soil again thoroughly. Plant seed. Replant missing hills. Cultivate like corn.
June-- Thin crop. Leave 3 plants to the hill. Continue cultivation.
July-- Keep crop clean of weeds, especially morning-glories.
August-- Remove male or blossom plants after pollen has dropped.
September- Cut and shock early crop. Beat out seed after 8 to 10 days in shock. Clean seed.
October-- Cut and shock late crops. Beat out seed after 8 to 10 days in shock. Clean seed.
November- Finish cleaning seed and deliver to designated receiving station.

Cooperative Extension Work in Agriculture and Home Economics: College of Agriculture and Home Economics, University of Kentucky, and the United States Department of Agriculture, cooperating. Thomas P. Cooper, Director. Issued in furtherance of the Acts of May 8 and June 30, 1914.

Our appreciation to Eric Skidmore for making this doucment available

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To North American Industrial Hemp Council