Guidelines for Sweetpotato Seed Stock
and Transplant Production

Revised 9/90 -- Author Reviewed 1/98 HIL-23-C

Jonathan R. Schultheis
Extension Horticultural Specialist
Department of HorticulturalScience
North Carolina Cooperative Extension Service
North Carolina State University

Sweetpotato production should be planned as a part of your total annual farm management scheme. Sweetpotatoes should not be grown just "once in a while" or just in those years you think you'll be able to "get rich quick." Commitment to an ongoing production program is required in order for you to be a successful grower.

Having your own good seed program indicates that you are committed to sweetpotato production and gives you confidence in the quality of the transplants you use for your crop. It gives you control over transplant production by providing you with the freshness and quantity you need when you want it.


The North Carolina Crop Improvement Association has been certifying sweetpotatoes for more than 50 years. The North Carolina Certified Sweetpotato Seed Growers Association works closely with them to supply the sweetpotato industry with quality seed. Field and storage inspections assure that your seed stock will have:

  1. Varietal purity
  2. A minimum of mutations
  3. Little or no serious disease problems

In most years, it is not possible to buy sufficient certified seed stock to grow your entire sweetpotato crop. Therefore, you need to develop and maintain your own seed program and integrate this into your commercial production program.

  1. Always use N.C. certified seed stock.
  2. Fill one-tenth of your total annual commercial seed stock needs with certified seed stock.
  3. Increase this certified seed stock for the following year's commercial crop.
  4. Keep your seed operations separate from your commercial operations.


  1. Handle seed stock (for production of next year's crop) separately from seed stock for the commercial crop.
  2. Presprout seed stock. Raise the temperature in the storage house where seed sweetpotatoes are to 75 to 85oF with 90 to 95% relative humidity for about 3 to 4 weeks. Provide some ventilation. Presprouting results in earlier plant production and 2 to 3 times more transplants.
  3. Bed site selection.
  4. Bedding.
  5. Cut transplants from the beds.
  6. Destroy bedded seed stock when you've finished harvesting transplants, by herbicide application, disking, etc.
  7. Planting.
  8. Harvesting sweetpotatoes.
  9. Cure seed sweetpotatoes at 85oF and 90 to 95% relative humidity for 4 to 7 days to help minimize potential losses in storage. Curing should begin as soon after harvest as possible.
  10. Storage.

For more information please refer to Growing and Marketing Quality Sweetpotatoes, North Carolina Agricultural Extension Service Bulletin No. AG-09, 1989, by L. George Wilson and Charles W. Averre. This publication can be purchased for $2.00 from: Department of Agricultural Communications, North Carolina State University, P.O. Box 7603, Raleigh, N.C. 27695-7609.

Always use pesticides according to label directions. The use of trade names does not imply endorsement of the product named nor criticism of similar ones not mentioned

Published by

North Carolina Cooperative Extension Service

Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. Employment and program opportunities are offered to all people regardless of race, color, national origin, sex, age, or disability. North Carolina State University at Raleigh, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating.