A properly cared for bed of asparagus can be a source of joy and tasty meals for many years.
While a good sized bed can be an effort to plant, requiring quite a bit of digging, lots of manure and compost and patience, it's an investment that really pays off - especially if you start with 2 year old crowns and practice a bit of restraint and judicious harvesting over the first couple of years. The great thing about this vegetable is that if you plant it right, you only have to do it once; asparagus is a reliable perennial that will be productive for 15 years or more if given proper care.
The first thing you need to know is how much to plant. The rule of thumb I follow is that it takes about ten to fifteen plants per person to produce enough asparagus over the course of its short growing season. Now when you plant it depends on where you live. In the south, you plant it in the fall; in the north, spring planting is preferred.
Once you have determined the number of plants you need it is important to purchase crowns that are healthy, with roots that are fresh and full of moisture. A crown is the root system of a one-year-old asparagus plant that is grown from seed. Avoid those that are dry and shriveled.
There are male and female asparagus plants. I prefer the new all-male hybrid asparagus varieties such as Jersey Giant, Jersey Prince, and Jersey Knight. These varieties produce spears only on male plants. Female plants expend more energy to produce seeds resulting in lower yields. The seeds can also become a seedling weed problem in the garden.
When you plant your bed, you will be wise to make sure the soil is right from the beginning. Because the plants will produce for years, work in plenty of well composted manure. Then dig a trench long enough to space your plants approximately 18 inches apart and 6 inches deep. Place your crowns in the trench and then simply cover them up with soil and water them in. Take care to not compact the soil over the newly filled trench or the growth of the asparagus will be hindered.
Since asparagus are heavy feeders, the manure gives them a good start, but I also fertilize them a couple of times a year and of course, keep the weeds down around them. And as tempting as it may be, it's best not to harvest the asparagus during the planting year.
Asparagus is a true teacher of patience, since it almost takes three years to really get them started. But once they're off and running, they'll produce for years to come.