If the bed is established, you normally should be eating all the early spears, picking the spears encourages the bed to grow more. Then stop harvesting and let the shoots mature into plants later to gather solar energy all summer. There are many opinions on the best way to grow asparagus, you could research and compare.

Most stuff I read said do not pick spindly spears, so I left some. I am reading more but have not found the answer to my question. In a nutshell when do the spears start giving back more then they take from the crown?

The spears of any size grow taller and taller and then make ferny side foliage which feeds the roots and allows them to make more spears/foliage to continue to feed the roots. Does this answer your question?

In an older, established bed the roots are quite large and the first/larger spears can be cut at ground level as food. When the spears become pencil-thin it is wise to stop cutting and let those develope the foliage that will now feed the roots.

Do you get good thick spears to eat now? I would cut them all now, even small ones. If they die with frost, you are right, there is no point in letting them grow up.

Now if you are getting mostly really thin spears with little to eat, that would be an issue, the bed may not be doing well and may need to be replanted or moved.

Also, Dave, are you fertilizing? A lot of people put on a layer of manure in the winter when all the foliage has been cut to the ground and all is snuggled-in for the Winter. Manure was never an option for me so I lightly dug-in vegetable garden fertilizer and that seemed to work too.

We have a hard freeze forecast for Sunday morning and 35F tonight. I am in a valley microclimate so I wouldn't be surprised if we get a frost tomorrow morning too if the skies are clear. I'll cut all my spears down that are over a few inches and hope for the best.

I'll put some AG19 over the beds but the winds are supposed to be over 20 mph so I doubt it will stay put.