Measure the sides of your fennel bulbs with the measuring tape to determine if they are nearly 3 inches in diameter and ready to harvest. Fennel bulbs can be harvested sooner, but begin to get tough when they are allowed to grow larger than 3 inches in diameter.
Use a garden trough to carefully clear dirt from the base of the plant. Wear gloves to keep your hands cleaner. Toss aside or kills any bugs you come across.
Hold the bulb firmly in one hand as you use the other to make a clean slice through the root just below the base of the bulb. Loosely replace the dirt that was removed so the root is fully covered.
Clean fennel bulbs under cool running water. Pull off the first layer of leaves to remove trapped dirt. The outer layer of leaves are usually tough and nearly inedible, similar to those of an onion.
Place your cleaned fennel bulb with stalks and leaves still attached into a plastic bag and store it for up to a week. The fennel flavors are most potent when the bulb is sliced and used right away, especially when eaten raw.