Biennials are crops that take two years to reproduce.
Which means you need to exercise a bit of fore-thought and planning when it comes to growing your own seeds for things like cabbage, carrots, and onions.
Biennial crops grow vegetatively during their first season. They store lots of carbohydrates in their leaves, roots, or bulbs respectively. Which is why these parts of the plants taste so good. Of course, if our plates don’t get in the way, these stores of carbohydrates will be used as food for seed in the second season. The plants want to produce as much seed as possible, as quickly as possible.
The key to seed production in the second year is vernalization: a period of cold temperatures that will prompt flower development. In the natural cycle of things, this period of cold is technically called Winter. In the more contrived process of a seed farm, the period is called a walk-in cooler.
At the end of last season, we harvested Calibos cabbage, Dragon carrots, and Rossa di Milano onions with our friends and collaborators at Blue Heron Farm. We packed the vegetables securely in clean sawdust and over-wintered them in the cooler at Blue Heron. Harvesting and storing the crops – instead of just leaving them in the ground – serves two important purposes.
First, we can be certain that the crops will be safe and secure for the second season. Leave them in the ground as Nature would do it and you run the risk of loosing your crops to rot, rodents, or other uncontrollable factors.
Second, pulling these vegetables out of the ground let us make an initial round of selections for color, shape, and size. There’s absolutely no reason to put time or energy into saving vegetables we don’t want to reproduce the following season.
When we pulled the crops out of the cooler early this spring, there was a second round of selection. The only crops going into the ground are those in excellent condition. How the cabbage, carrots, and onions looked on the outside was important: good color and no rot. But looking inside was important too, so we cut open the onions and carrots. We were looking for onions with only a single growing point and carrots with the most robust color of orange. Cutting open the carrot also let us do the all-important taste test.
Admittedly, it feels weird to cut open plants that you plan to put in the soil. But there are some counter intuitive benefits. Cutting away the leaves of the cabbage make it easier for the apical bud to emerge and grow. The same is true for cutting an onion in half and planting the round bottom portion. Cutting the tip off a carrot at a diagonal allows for better contact with the soil. And one more taste test before planting.
Biennials are crops that take two years to reproduce. Which means we’re only half way to our intended goal. But so far, so good.
We’ll see what these particular vegetables still have to teach us this season.