In the Garden: Grow beet family crops, and cover them to keep pests away

Some of my favorite cool-season crops are beets, spinach and Swiss chard. They all belong to the same plant family, Amaranthaceae, so they have the same cultural needs and potential insect problems.

In the Inland Northwest, the seeds can be direct-sown in the garden around April 15. I don’t add any fertilizers to the soil to prepare, although I do add an inch of compost to the soil surface in the fall and again in early spring. It isn’t necessary to work the compost into the soil, as the nutrients will filter down into it all by themselves.

Beet and Swiss chard seeds are unusual in that each one is actually a cluster of seeds. You will be relieved to hear you don’t need to separate them. Plant the seeds of all beet family crops 1/2-inch deep, and space the rows 12 inches apart. Water them well.

Members of the beet family are susceptible to an annoying insect called the leaf miner. The adult form is a fly that lays eggs on the leaves of the plants. The eggs hatch into tiny larvae that tunnel their way through the layers of cells in the leaves.

If you’ve ever seen beet, spinach or Swiss chard leaves that have squiggly lines running through them, or perhaps what appears to be a clear window in the leaves, that is the work of leaf miners. I don’t know about you, but the last thing I want to eat for dinner is little worms. Fortunately, there is a very simple way to avoid this problem.

As soon as you’ve sown the seeds, install hoops over the planting bed, and place a sheet of floating row cover on top of the hoops. Many organic farmers use this lightweight fabric as a barrier to keep damaging insects away from their susceptible crops. I love using row cover because I’d much rather exclude insects from a planting than try to wipe them out. Find these covers in garden centers or online.

Be sure to weight down the edges so it won’t blow off. Since beet family crops don’t require pollination, you can leave the row cover on them for the entire season.

Slugs also can be a problem, but there are simple organic methods for dealing with them. Consider making a beer trap by sinking a tuna or cat food can in the soil with the lip at the soil surface. Fill the can halfway with beer. The slugs are attracted to the smell of the yeast, fall in and drown.

There also are organic slug baits available, or you can sprinkle diatomaceous earth around the base of the plants. Diatomaceous earth is a flourlike substance that garden centers carry and is made from the fossilized remains of algae. It has tiny, sharp edges that cut the slugs’ skin, causing them to dehydrate and die; usually they won’t want to cross over it to get to the plants.

To give the crops enough room to grow, thin beet seedlings (not the seed clusters) 3 to 4 inches apart, Swiss chard 6 to 8 inches apart and spinach 4 to 8 inches apart.

Be sure to harvest spinach and Swiss chard leaves while they’re young and tender, picking individual leaves rather than a whole plant at a time. This way, the plants will continue to produce. Beets can be harvested any time after the roots reach 1 inch in diameter.

All of these crops make a wonderful addition to the spring garden.