How does one tell asparagus males from the females, & what difference does it make? Can't seem to find much info on this subject. Although 'everyone' agrees that male plants are better, I have not heard an explanation about why or what to do about it other than planting an all-male variety to begin with.

I planted a bed of Purple Passion from seed 3 years ago. 25 seeds made 25 plants, which I put into a 4x12' raised bed. The spears I get are luscious, sweet, tender ... but sparse. I think the plants are mostly females. Last year by fall it looked like a fern forest in that bed, and the plants were totally covered with little red berries. This spring there are only a few plants that have made spears at all. There are huge numbers of seedlings (surprise!).

Question: Do I mark, dig up & replace the female plants at the end of the season? Are the productive plants (the ones that are up now) the male ones? In that case, maybe I should dig up the skimpy ones now & replace them with new crowns immediately. Can one tell the difference between M & F in the spring? And, will the seedlings come true? Should I save them, or are they "weeds"?