The quick-to-sprout radishes will push up through the soil, breaking it up for the later-sprouting carrots.
Here’s a tip: Radish seeds are natural companions to carrots. Mix radish and carrot seeds before you sow, especially if your soil develops a tough crust. The quick-to-sprout radishes will push up through the soil, breaking it up for the later-sprouting carrots. As you harvest the radishes, the carrots will fill in the row.