how long can you keep an asparagus bed going?

I have a nearly 16-year-old asparagus bed which is, to all outward appearances, thriving.  But Rodales publications and Extension websites say that asparagus beds can last 10-20 yeas,or up to 20 years.  That's all they say about it--I don't see anything about whether they fade out slowly, or stop producing suddenly, or whether there is any way to renew them. I'm trying to figure out whether I need to start a new asparagus bed in another part of the garden. If any of you have grown asparagus over a long period of time I'd be glad to hear about your experiences.

Background info: In 2002 I planted 25 crowns of asparagus--I think they were Jersey Knight, but in the confusion of our first year on the land I mislaid the records--in a 50-foot-long trench in the middle of my garden. (The native soil here is basically sand and stone; we've been pouring compost into the garden for the last sixteen years.)  Production ramped up slowly and seems to have held about level for the last ten=plus years, with some fluctuations which I ascribed to weather. We're running drup irrigation on it (I just learned this winter that I should stop watering in September. Oh well...) In fall I cut and remove the ferns (because we have a lot of asparagus beetles) and put on 1-2" of compost (which stays there) and another 6"or so of hay and/or leaves (which come off in spring.) I've seen no signs of disease, though the beetles are persistent. I also side-dress with compost after the harvest ends in late June or early July.

(In case this doesn't just appear in my signature, I am in zone 4/5, upstate NY near Lake Ontario, where the weather fluctuations,both of moisture and temperature, are extreme and getting more so.)

My asparagus are only 6 years old.

With this level of attention I don't see why this level of production should not continue . Remember that this is not commercial production we are talking about , such producers have different economics . I suspect they achieve larger yields but then have huge inputs and after twenty years the ground is warn out .whilst you are building fertility every year

David

Most literature on Asparagus beds will quote 20 years of productivity.
This is most likely so you will buy more crowns to plant.

Case in point, I have harvested from a bed that was 18 years old (not mine) and I know people who are still harvesting from a 50 year old planting (one acre).
If you are not building the soil but harvesting all spears possible every year, then perhaps the plants would exhaust themselves after 20 years.
More likely, if you harvest for 6 to 8 weeks then let the rest of the spears grow out and you don't cut those but let them die back on their own, then you might never have to replant, ever.
The crowns will reproduce if allowed to and that means that while a specific plant might die, there would already be replacements in place.

I know of a bed in Up state NY that in 1968 had been producing for over 100 years. It was planted by the land owner's great, great grand father when he was a child.
Knowing that, I can't tell you how long one can survive but it would seem to me that 200 years would not be out of reach. I think it would mostly depend on the harvest pressure and soil care.

Since you know the planting date, if you were to keep a record book on this bed, you would be able to document every phase as well as all the soil care given. That would be awesome data to have access to for future planning.

Redhawk

Asparagus are biennial. As Redhawk mentioned, if you leave some each year to die off naturally, you're just getting those last plants to stock the soil's seed bank next year for the following season.

If you are treating the bed as a perennial crop, your concern will be ensuring that the soil stays vital and nutrient and mineral-rich.

-CK

I have a bed about 20 years old that has been fading on me.  I think the crowns are too dense and need to be split, but have been warned it may require a backhoe to get them up!

I also started to have problems with asparagus beetles a few years ago and that coincided with the decline as well.  I think those are under control (hand collection and cleaning up the seeds in which they overwinter) but that might be a contributing factor in my situation.

My family farm has an asparagus patch planted by my great-grandfather. Probably in the 1920s or 30s.
It is a slowly spreading patch, so every spring we give away huge amounts. Only shoots that haven't started branching are harvested and only in May and June.
Asparagus is a heavy feeder, so some sort of compost is important. Our patch gets animal manures, cattle manure for many years, more recently composted sheeps manure and composted chicken bedding. This has been going on for so long that the asparagus patch is a hill.
Keep pilling the compost on your patch and it will get better every year.

We had one at another house. We moved after 10 years, but since it was Mary Washington, it had seeds, and new plants were growing all the time.  I think it could have grown indefinitely with proper composting, diversity, water, etc.
John S
PDX OR

Hey Kids,

The old farmer known as Mom, says that for true production they would harvest the roots and replant. Mainly space and ground issues. However, in the garden, she says it can be indefinite but they moved them for disease and they just did better. Fair enough. Asparagus is not her fav product so she did not dwell on it. Dad said his mom planted under certain trees and then in the summer used it as flower beds. between the rows of fern. Hmmmmm I wonder if there was a relationship? My relatives threw out all her notes. Sorry, I cant do more for you. The ferns are nice. I remember walking among them as a kid.

I will note. Waste from the barn (composted a year) and kitchen went into those beds.

Asparagus is perennial, and most varieties have both male and female plants, and the female plants can produce copious seeds. If yours haven't produced a whole lot of new seedlings over the years, then it sounds correct, that you planted the male-only Jersey Knight.

Our asparagus bed is 100+ years old. Our family has been here a long time. It was here before us. The rhubarb bed next to it has been here just as long.