My Burpee Basil Seeds Are Not Germinating

Timing

• Basil is considered a tender annual and requires frost-free weather to germinate and grow. Impatient gardeners sometimes jump the gun and plant too soon. The optimal soil temperature for basil germination is 70 degrees Fahrenheit. If the soil temperature dips below 60 degrees, the seeds won't germinate. Use a heat mat if you are germinating the seeds indoors. Gardeners who direct-sow should wait until the soil warms and replant. To determine the soil's temperature, insert a soil thermometer 4 inches into the soil and record the temperature. Repeat the procedure for at least three days. When the soil temperature is above 60 degrees for three days, it is safe to plant.

Soil Problems

• Basil germinates best in slightly acid soil, with a pH of 6.4; pH testing meters are available at many gardening centers and nurseries. You can also have the soil tested professionally at the county cooperative extension office. After rectifying pH problems, the soil should be aerated to make it loose and airy. If the soil is too heavy or composed mostly of clay, the seed may not germinate. Add coarse sand to the soil and incorporate it to a depth of 4 inches. Avoid walking on the soil.

Planting

• It is important to incorporate fertilizer into the soil before planting the basil seed; 4 oz. of 4-6-4 fertilizer, mixed into the top 6 inches of soil, is sufficient to help germination. If the seed is planted too deep -- more than 1/8 inch deep -- it won't germinate. To assure the proper planting depth, place the seed on the surface of the soil and sprinkle the covering material -- sand or vermiculite -- over the seed.

Disease

• Fungus, bacteria and viruses may live on or in the seed, causing failure to germinate. Some seed companies pretreat or test seeds to ensure that they don't contain diseases. Although some of Burpee's large line of garden seeds are pretreated, basil is not. Burpee offers San Remo basil seeds, which are disease-resistant. Check seed packets to ascertain if the basil seeds are disease-free or resistant. Treat uncertified seeds before planting by soaking them in cold water for four hours and then placing in hot water -- 136 degrees Fahrenheit -- for 20 minutes.