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Horticulture and Home Pest News
Horticulture & Home Pest News is filled with articles on current horticulture, plant care, pest management, and common household pests written by Iowa State University Extension specialists in the Departments of Entomology, Horticulture and Plant Pathology.

Supplies for Starting Seeds Indoors

This article was published originally on 2/8/2012

For many home gardeners, starting seeds indoors is great fun. Successfully growing seedlings indoors requires high quality seeds, a germination medium, containers, lights, and other supplies.
 
Seeds
 
Flower and vegetable seeds can be purchased at local garden centers. They're also available from mail-order companies. Mail-order sources include Stokes Seeds, P.O. Box 548, Buffalo, New York 14240 (www.stokeseeds.com); Park Seed, One Parkton Avenue, Greenwood, South Carolina 29647 (www.parkseed.com); Johnny's Selected Seeds, 955 Benton Avenue, Winslow, Maine 04901 (www.johnnyseeds.com); Harris Seeds, P.O. Box 24966, Rochester, New York 14624 (www.harrisseeds.com); and many others. 
 
Germination Medium
 
The germination medium should be lightweight, porous, and free of pathogens. Excellent seed-starting media are commercially prepared soilless mixes, such as Jiffy Mix. Use a high quality, well-drained potting mix when transplanting seedlings into individual pots or cell packs. 
 
Containers
 
Various containers can be used to germinate and grow transplants. Gardeners can purchase flats, trays, pots, compressed peat pellets, and other products. Previously used flats, trays, and pots should be cleaned and disinfected before use. Wash previously used containers in soapy water, and then disinfect them in a solution of one part chlorine bleach and nine parts water. Cut-off milk cartons, plastic jugs, paper cups, plastic food boxes, and other containers can also be used to start seeds. Holes should be punched in the bottom of milk cartons, jugs, paper cups, and similar containers to allow for drainage.  
 
Uniform moisture levels are required for optimum seed germination. To maintain uniform moisture levels, place clear, plastic wrap over the containers. Flats can also be covered with clear, plastic domes. 
 
Lights
 
While plants can be grown in sunny windows, they often become tall and spindly because of insufficient light. For best results, grow seedlings under fluorescent lights. Light stands are great, but are rather expensive. A standard fluorescent shop fixture containing two 40-watt tubes is a much cheaper alternative. For best results, place one cool white and one warm white tube in each fixture.  The fluorescent lights should be no more than 4 to 6 inches above the seedlings. A timer can be used to turn the lights on and off. 
 
Other Materials
 
A few other materials are also helpful. A rubber bulb sprinkler is a handy watering aid. The sprinkler produces a gentle spray which won't dislodge the seedlings or wash away the potting mix.  Most seeds germinate best when the medium temperature is consistently 70 to 75 degrees Fahrenheit. Placing containers in a warm location in the house, such as on top of a radiator or near a heat register, usually works fine. In cool environments, electric heating cables or mats can be used to insure warm medium temperatures.