To grow asparagus, you'll first need to choose between growing from seeds - which takes up to a year longer, or growing directly from crowns. Once the decision is made, choose a sunny spot with proper drainage, dig a trench in the dirt, and plant your choice, covering them with around 2 inches of dirt to start. Choose a spot carefully because asparagus need lots of space, and will continue to grow year after year for up to 20 years.
Consider the climate carefully when planting asparagus. California varieties are more heat tolerant, while Jersey Giant tips may loosen in warmer weather, so matching the proper variety to the weather conditions is essential. When growing from crowns select fresh firm roots. Roots which are shriveled looking will not result in healthy plants.
Once the trench is dug, plant the crowns 6 to 8 inches in the ground. Space the plants 15 to 18 inches apart and leave five feet between rows. This allows good air circulation to all of the plants, and helps to prevent disease. Be sure to control weeds in the area where the asparagus are planted as well, and protect asparagus from pests such as the asparagus beetle. Inspect asparagus for black eggs and remove with a dull knife or fingernail.
Asparagus have an extensive root system, and therefore do not typically require a lot of water, unless they are planted in a very dry climate. Harvest spears by hand, just about the level of the soil when they are six to eight inches tall. All of the stalk harvested is edible.