Last year we got an AeroGarden and this past April I finally set it up. The AeroGarden came with the herbs pack and the first thing to successfully sprout and thrive was the Genovese Basil.
The problem now is, the basil has gotten so big that it overshadows the other herbs that were planted. I let the basil go too long without pruning because I wasn't sure how I wanted to preserve the leaves and I haven't needed fresh basil yet.
So here are a few ways you can harvest your basil (and other herbs) so that you can not only keep your plant healthy and thriving, but have basil available whenever you need it.
Step 1: BoM
Herbs (that are in need of harvesting)
Sharp scissors/gardening snips
Air tight jars
Mesh fabric (for drying)
Step 2: Prune
When harvesting basil you want to look for the two largest leaves on a stem, just below those you should see another set of leaves or little knobs (nodes) that are growing in between the stem smaller set of leaves. Cut the stem 1/4-1/2" above the nodes. Repeat this with all the larger leaves on your plants
When you've harvested the majority of the plant, look around for other large leaves that are ready to be used and trim those as well. Try to avoid the leaves on the bottom of the plant.
Step 3: Air Dry
One way to dry basil is to tie the stems together with string or a twist tie and then hang it in an airy space, out of direct sunlight. I've found a decent sized binder clip also helps keep stems from falling out. After a few days the basil will be dry enough to be put in a jar for later use.
Step 4: Microwave/Oven
You can lay your basil leaves (spaced apart) out on a paper towel and microwave for short 15-20 second intervals until the leaves feel dry, at which point you can then crumble them up and put them in a jar for later use.
You can also put your oven on a very low setting and slowly oven dry your leaves on a cookie sheet.
Step 5: Freeze
You can freeze your basil in olive oil. Chop up the basil, add it to a bowl with olive oil and mix. Then pour the mixture into small molds, wrap and freeze for later individual use.