Asparagus that is available in the market is mostly one year old but if you are really eager to start harvesting, you can also buy the older ones. Keep in mind that if you buy one year old plants, they will require about three years before you can harvest them. Some nurseries do carry asparagus plants but they commonly come in mail order. At the time of collecting the crowns, you must ensure that they are disease free. It is recommended that you order your asparagus crown in fall, so that you receive them in time and harvest them at the start of the spring season.
Site of plantation
As long as the soil has good drainage, asparagus can be planted in almost any kind of soil. You should add a lot of nutrients for the roots to collect and any compost incorporated into the soil will enhance the drainage. It is strongly recommended that you use a garden fork or a tiller to break up the soil to approximately 12 inches deep. This should help you in getting rid of any kind of debris that is present. It is important to know that asparagus should not be planted in an area where corn has been planted in the past.
Plant the crowns
If you are living in the US, early spring (from April 15 to May 15) is the best time to plant the asparagus crown. Dig trenches which should be four feet apart and about six to eight inches deep. Mix a couple of inches each of sand and manure into the bottom of the trench if the soil was not amended earlier. Spread the crown in the trench and fill in around them to the top. You can fill the rest of the trench in the same manner.