Planting asparagus from seed has some advantages and disadvantages. It is a little bit more work, but typically costs much less also. The biggest disadvantage is you will have to wait an extra year to harvest your first spears.
Asparagus seeds started indoors should be started in 4 inch pots approximately 3 months before the last frost. They will germinate best at daytime temperatures at around 75-80 F, and a low temperature at night of around 65F. It may take as long as 3 weeks for the asparagus seeds to germinate. To hasten germination, soak the seed for 48 hours in water prior to planting. Sow the seeds approximately 1/2" to 3/4" deep in rows approximately 2 feet wide. Seedlings should be transplanted or thinned to a minimum of 3-4 inches between plants. These seedlings should grow for a summer, and the following year the 'yearlings' should be transplanted to the permanent asparagus bed.