Gerald from Zone 7
For spring planting beets, it's best to wait until the soil warms to around 50 degrees. Once you make your little shallow furrow and plant your seeds, it's good to cover them with fine soil. You want to break up any lumps, you don't want any twigs in there that would inhibit the seedlings from coming up. Now, if I have Gardens Alive! Earthworm Castings, I like to sprinkle that in the furrow and cover them with like a quarter inch of the worm castings, and that allows that seedling to pop up freely, and it gives you the little extra boost of fertility.
The other big important factor is keeping the seed bed evenly moist while they're germinating. You don't want it to dry out and form a hard crust on the surface, because it makes it hard for the seedling to come up.
For my late summer fall crop, I'll often put shade cloth or insect barrier over the planting bed. That keeps the soil temperature a little cooler and helps keep the soil moist.
You also want to be mindful of insects. Thrips and cut worms can cut off and eat those little seedlings before you even see them, so you might have that issue in your garden. You just have to be mindful of that.
And finally, as an alternative, you can start your seeds indoors. I start mine in our Gurney's seed
starting kit. Just sow 2 to 3 seeds per plug, and grow them inside under lights for about 4 to 5 weeks. Then plant them out in your garden.