Have you seen white asparagus?

This is white asparagus

The asparagus remains white because the spears don't receive sunlight, so they don't produce green chlorophyll. 

White asparagus requires the same care as green spears, except you must prevent access to sunlight during the productive weeks when the harvestable spears are putting on new growth.

This is a mature asparagus

They do looks like fern! Unlike most vegetables, asparagus plants are perennial, which means the same plants grow in your garden year after year. The spears that we enjoy as a vegetable are the new shoots that emerge in spring. The most important part of growing asparagus is to realize that it will take a couple of seasons before you taste the first bite of homegrown asparagus. Plants need to be allowed to mature before you can harvest.

 Asparagus can be grown in most parts of the country, but does especially well in cooler regions with longer, colder winters. These periods of dormancy allow asparagus stalks to grow more robustly in the spring than they do in warmer regions with milder winters.

http://homeguides.sfgate.com/grow-white-asparagus-63563.html
https://bonnieplants.com/growing/growing-asparagus/