Growing asparagus from seed - either in pots or directly into the beds - gives the best viability, with a survival rate of around 100%. In addition, with direct sowing there is no transplanting or root shock to delay valuable root development.
The best time to sow asparagus seeds is around mid-April when the ground is warm enough to initiate germination. A good tip is to soak the seeds in water for a couple of hours before planting. You will find that this will help to speed up the germination process considerably.
As soon as the bed has been prepared, rake over the top layer into a fine tilth, then sow the seeds into thin rows down to a depth of about 2 inches. Each subsequent row should be between 12 and 18 inches apart. Water them well if conditions are dry. The new seedlings should emerge in about 3 weeks. As soon as they are large enough they can be thinned out to about 2 inches between plants. Once the seedlings reach about 6 inches high they can be thinned out again to around 16 inches apart. For the rest of the year you just need to keep the beds weeded and the plants well-watered. You will need to remove any female forms as soon as they become identifiable - normally from their berries.
It is best to sow the seeds in individual pots. It doesn’t hurt to soak the seeds for several hours in warm water prior to planting. Place the pots in a warm room at under lights. Germination should occur within 3 weeks. Once the danger of frost is passed you will need to “harden off” for at least a week. Once they are ready to be moved out into the asparagus bed they can to be planted fairly deeply, leaving a couple of inches of soil above the level of the compost. Keep them nicely watered over the summer period and - as always - keep the bed free of weeds, especially perennial weeds which will compete with your seedlings roots for nutrients. Growing your own plants can delay establishment of your bed by an additional year, but it does ensure that you are starting with new crowns that have not lost vigor from being lifted, stored and shipped. Begin harvesting the second year.