When it comes to watering beets, be pay attention to how well the soil drains. Like other root vegetables, beets tend to rot if they sit in soggy soil for extended periods of time. On the other hand, they won't grow well if they don't get enough water. Because they are a fast growing crop, we recommend adding fertilizer or compost to the soil before planting beets.
Beets will do well with several moderate watering sessions, as opposed to a single deep soak. To check to see if your beets need to be watered, dig down into the soil with your fingers near your beets crop. You want the soil at 3" deep to be slightly moist. If it's wet, hold off on watering. If it's dry, give them a shallow soak. If you don't get any rain, a light to moderate watering twice a week is usually enough.
When watering, be careful not to wash away the soil around the beets. This is especially important if you are growing them in raised rows. We find that a simple overhead sprinkler does a good job of getting the ground wet without causing soil erosion. Leave it on your beet crop for about 10 minutes or so, and that's usually long enough to give them the water they need.
To help the soil retain moisture and to prevent erosion, you can use mulch around your beets. Grass clippings, straw or chopped up leaves work well for mulch. It's best to wait until the beet tops are a few inches tall before adding mulch.
Most varieties of beets are ready to harvest in about 2 months, sometimes even less. Because of this, we like to add nutrients to the soil before planting. Compost and well-rotted manure work fine, as does a granular fertilizer product. Just make sure to apply it early enough to be able to work it into the soil and then water it in before planting.
When choosing a fertilizer, look for something with more phosphate and potassium and less nitrogen. Pay attention to the 3 number code on the package of fertilizer. These three numbers indicate the amount of nitrogen, phosphate and potassium that are contained in that particular fertilizer, respectively. For instance, a 10-10-10 fertilizer contains 10% nitrogen, 10% phosphate and 10% potassium. A 5-10-10 bag would contain 5% nitrogen, 10% phosphate and 10% potassium. Nitrogen encourages a plant to produce more foliage. Phosphate and potassium encourages more root development. Because beets are a root vegetable that grow below the surface of the soil, phosphate and potassium are more beneficial to beet growth.
If you want to grow beets more organically, compost, well-rotted manure, bone meal and wood ashes all work fine for growing beets, depending on the make up of your soil. You can work them into the soil before planting.
Now that you know about fertilizing and watering beets, it's time to think about harvesting them.