Thinning Seeds

Killing Plants on Purpose

See how to thin kale and other winter greens in this video.

Thinning is just a fancy way of saying killing or removing seeds that sprouted, so that the resulting plants will have the space they need to mature.

Which is good, because so many seeds are TINY. Like, poppyseed size, tiny. Smaller than a grain of rice. And if you are like me with your fat fingers, there’s no way you can pick up one at a time. And you laughed and laughed when the packet said to put 3 seeds every 18 inches. HA, those things went everywhere.

Your seed packet likely had instructions on when and how to thin, but those instructions are a little sparse. Do you cut them? Or pull them? Do you thin all at once? Or, do you thin over the course of a week or two?

At this point, you might be asking yourself why direct sewing seeds is better than buying transplants from your local nursery. For certain plant types like greens, direct sewing of seeds is often better than buying transplants. A few benefits:

• Economics: One packet of 25 or more seeds can be $3 to $5 dollars, where a single sprouted transplant from the garden center can be the same price.

• Health: Many plant types actually do better when directly sewn, as the shock of transplanting can stunt their growth, and the plant ultimately does not put down a root system that was as healthy as if it was directly sewn by seed.

• Microgreens: Every thinned seed is a microgreen. So, if you feel bad about killing baby plants, just rephrase it in your mind as ‘harvesting microgreens’.

Let’s use Kale as an example. Kale should be planted in a bunch of 3 seeds every 18 inches. The reason is you never know if a seed is going to be a dud. So, you should plant more than one per hole to hedge your bet. But, if you’re like me, you planted like…8 (fat fingers, remember?)

A week later and now you’ve got 7 baby kale that have come up. They are already going sideways because they are fighting for light. This is when you start your ruthless rule as Cesar and your little baby kales are gladiators fighting till the last stalk. A few of them have to go if you want the victor to be strong. So, you pick the weakest 50% of them and CHOP.

A few days later, you do the same again. And a few days later, again. Until you have one victorious plant that will be the plant in that spot.

To thin seeds you can either cut them, or pull them. I personally prefer the cutting method. You’d be surprised how quickly a seedling can put out a root system. When you have 3-10 seedlings in a bunch and you yank out a seedling, it pulls the soil away from the other seedlings in the bunch, which disrupts the seeds you want to stay in the ground and live. So, I prefer to cut the plants out that I want to remove. This kills the seedling marked for death and leaves the soil undisturbed for the survivors.

What you'll need:

• Scissors: The finer the point the better, to wedge the tip between the little seedlings.

• Your hands: Eh, sometimes you do end up yanking out a few.

• Bowl: For all of the microgreens you’ll be harvesting during the thinning process.

Every plant needs enough sunlight, water, and nutrients to survive. Thinning seeds makes sure that the plant that remains is a healthy vigorous producer in your garden. Go ahead - be ruthless.