Organic mulch feeds soil microbes, keeps down weeds, holds in soil moisture, and most importantly for beets, cools the soil up to 6 degrees compared to bare soil. As soon as the beets are four or five inches tall, add a two to three inch layer of organic mulch such as chopped leaves, hay, or straw. Keep this mulch in place until harvest time.
For more information see file on Using Mulch In The Vegetable Garden.
In the beginning, after planting seeds, you must be sure that the seedbed never totally dries out. You can keep it moist with a sprinkle for the watering can every few days.
Once the beets are growing, they need about the same amount of water as most other vegetables in the garden. If you have good soil with lots of organic content and assuming you are smart enough to have 2 to 3 inches of organic mulch around your beets, then you should not need to water unless you have gone a week to ten days without a decent rain.
When you do water, make sure it is sufficient to reach down 8 to 10 inches into the soil. For more information see Watering The Vegetable Garden
Fertilizing requirements are a function of how good your soil is. With good healthy soil with lots of organic material, you need little fertilizer. With lousy soil you will need to fertilize more often to compensate for that dead soil.
Beets are considered to be heavy feeders. In gardener’s parlance that means they really do need to have some fertilizer during the season to grow properly.
The easiest method is to add some slow release nitrogen fertilizer in granular form to the seedbed before planting your beets. This fertilizer becomes the main meal for the beets for the season. If you did nothing else, you would enjoy your beets. If you have bad soil, you should sprinkle some slow release granular fertilizer around the plants 4 or 5 weeks after they emerge as seedlings.
If you want to have maximum production from your beets then you will give your plants two or three light supplements (sort of like giving them snacks) every 3 or 4 weeks using a foliar spray of a diluted liquid fertilizer, preferably one with some kelp included.
For more information see Fertilizing the Vegetable Garden
Using Shade Cloth
Here is a trick to extend the season for growing beets. Beets don’t do well in July and August when temperatures exceed 80°F and the days are long. While still in the experimental stage, some gardeners are finding that using the shade cloth, now available in most garden centers, over the beets during June, July and August reduces problems considerably. Rig it to sit about a foot above the beet tops, leaving the sides open for ventilation. You are primarily concerned about protecting the plant from mid-day sun. Morning and late afternoon sun are not as hot.
See Yardener’s Tool Shed for information about buying shade cloth. Go to the Products to Protect Plants section or type “shade cloth” into the search function on the left.
Thinning Beet Seedlings
Beets are planted with the intention of having them initially too close together so that over time you can thin out the plants for salads and cooking. Since each beet seed is actually a fruit containing three or four seeds, plants will come up in bunches. You start thinning when the first true leaves appear when the plants are one to two inches tall. Thin so all the plants are about one inch apart in all directions.
When the plants are about 4 inches tall thin all plants to two inches apart. Finally, when the plants reach about 6 inches you thin them down to the final 3-inch distance you need to allow the remaining plants to mature with sufficient space.
Scissors Trick – No matter how careful you are, thinning tiny seedlings usually leaves the remaining plants stressed a bit because it’s impossible not to disturb the soil around their roots as you carefully pull up their neighbors. We have found that a pair of fingernail scissors or other small scissors reduces this problem, especially for that first thinning. Just cut off the little plants that must go and leave them on the ground to become mulch.
Remember, beets normally grow with half of their root showing above the soil level, so if this is your first year with beets, don’t worry when you see those roots sticking up out of the ground.