How to Harvest Basil for Pesto

Plan to pick the basil leaves just before the plants flower. Basil plants tend to flower when they have six leaf sets on a stalk; therefore, plan to pick the leaves when there are four sets. Typically, basil plants are ready for harvest about every three weeks.

Locate the area where the leaf meets the stem. Basil leaves grow in sets, and the leaves are located opposite each other on the main stem. At the same leaf junction, you will likely spot a pair of small basil leaves growing as well. Cut your large basil leaf by its stem with a pair of scissors or gardening shears, directly above the smaller leaf. Doing so stimulates the smaller leaf to start growing. Since pesto requires large amounts of basil, plan on harvesting a lot of leaves, typically about 2 cups.

Use your basil in pesto as soon as possible because the fresher the basil is, the more flavor it has. Place the basil in a vase or glass filled with water until you are ready to use it, or store it in a sealed plastic bag at room temperature, which typically keeps for 10 to 14 days.

Freeze the pesto you cannot use right away. Pour the paste into an ice cube tray, then remove the cubes once frozen and transfer to a freezer storage bag. Pesto typically also freezes well in small plastic storage containers.