One of the hardest parts of gardening is deciding what dies. I am not a mean person, but sometimes things just have to go, and in the plant world that means death. I have to kill delicate little harmless green sprouts that had the potential of producing amazing edibles that could have gone to me or my friend’s plate.
In your gardens, the seedlings should be coming up now and will be putting on their first true leaves. It is an amazing part of gardening. The hard work of tilling and planting is over and now there are green rows of plants offering the promise of tasty meals to come. But this is only going to happen if there is enough space.
When I taught a weed science course at Washington State University, we had a plant competition lab where we planted barley (the weed) with radishes (the crop) in large pots. Every pot got eight radish plants, but the barley plant number was variable (0, 2, 4, 8, 16 or 32). After a few weeks, the students harvested all the plants and weighed the barley (leaves) and radish plants (leaves and bulbs). The weed-free radishes were great and after weighing, they were eaten. Pots with eight or more barley plants did not have any radish bulbs, even though there were lots of radish leaves.
At eight radish plants per pot, we had the perfect spacing for the plants. Any new plants introduced competed for resources. The plants in our study had plenty of water with fertilizer so that was not the problem. The problem was the lack of enough light. The amount of light could not be increased based on the number of plants in the pot. As a result the radish plants growing with the barley spent their energy growing leaves to get the light they needed and nothing was left for the bulbs.
This lab scenario is the same problem we experience in our gardens. We can give the plants water and nutrients, but we cannot give them extra light if they get crowded. Therefore we have to thin and that means killing the weak. Seed packages come with row-spacing information and spacing between plants in a row. Follow those directions. You will not get a carrot that you can take to the Tanana Valley State Fair to enter in the vegetable competition if it is growing side by side with four other carrot plants. Look at those five carrot plants growing together. Ask yourself, which are the smallest? And then kill them.
But wait. What is the best way to kill them? Well, that depends. Carrots have long roots and they are small as seedlings. If you pull one up, you might pull up all five. So just cut the tops off the weak ones. If the seedlings are more widely spaced, but still too close, then you can pull the small ones without disturbing the plant that you want to survive.
This need for early thinning is true for all the plants you grow. If you have too many in the space you have to grow them, they will not get enough light and you will get tall, leafy plants with no fruits, bulbs or flowers. Even for leafy crops such as kale or lettuce, if they are too crowded they will spend their energy growing tall. For example, it takes a lot of energy for a kale plant to produce a stem, and that energy loss will result in smaller, more bitter tasting leaves.
So, identify the best plants, kill their neighbors that are too close, and throw their carcasses in the compost. And with that message — happy gardening.
Steven Seefeldt is the Tanana District agriculture and horticulture agent for the Cooperative Extension Service, a part of the University of Alaska Fairbanks, working in cooperation with the U.S. Department of Agriculture. He can be reached at 907-474-2423 or firstname.lastname@example.org.