you can crowd em a bit and , after about a ywar, the sparagus will start sending up spears . You pick em when they are no thinner than a pencil. (In the beginning of the season, after about 4 years, they will produce heavily about 3 spears per day per plant (assume that you water and feed with horseshit or sheep **** compost) no carnivore or omnivore **** compost.
When you first picke em, they will be firly thick and, as the season progresses (YOU WILL GET TIRED OF ASPARAGUS) , or about 3 weeks, the spears will start getting thinner and thinner. I stop picking hwhen that pencil size is reached (If a couple of thick ones come up and a few pencil sized ones, leave the pencil sized ones go and pick the fatter ones). Soon they will all be thin and you stop picking for the year. Then I always side dress with some hay or manure and let em grow and bloom and do whatever it is they like doing.
Ive had an asparagus patch that we inherited with this farm and that was over 27 years ago and the previous owners said that they lived there 40 years and it was there when thye moved in. The secret was to go in with a tiller every 5 or so years and tear up the rooted crowns, then the plant sets out newer crowns like a forsythia bush.
I then planted 25 more bushes and that fed a family of four with enough to take to school or work and give em away to whoever wanted em. They can get like zucchini where people will see you coming with a big armfull of asparagus and they will cross the campus waay out in front so they dont have to meet up with you and take asparagus.
those 25 bushes were planted aboput 15 yers ago and they are all MALE bushes so they dont screw around getting ready and wssting time in the bathroom when you are late for dinner or you have an important engagement and she is all, like "Ill be down in 5 m inutes " and 20 minutes later youre still....... WAIT,, (deep breath , must only consider asparagus).
The male bushes dont produce the seeds and will start producing heavily after year 2. They are a bit more expensive , but they have a better return. They are hardier when planted and, they really set out fronds all summer. An asparagus is also a neat border plant with daisies or any procumbent plant like trailing mint or thyme. You can mix other veggies in there and they keep a nice habit all summer.
2 adults, = 10 asparagus will give you enough to eat fresh and also for freezing.
Now get going and order the fronds.
IF THEY COME WITH MOLDY BOTTOMS (fleshy roots) send them back because they rot easily in transit if they are not handled well.