I wouldn't....unless you want black pesto.
Keep the bloom picked off and water and it will produce more.
I make pesto as soon as I pick the basil....basil doesn't like cold!
Linda C

Once it's black, it is no good. Your refrigerator may have cold spots, and basil can get damaged at 35 degrees.

If you have a good plant, it can last for over a year, although it will not make many leaves unless it gets enough light, as in a greenhouse. I have a basil plant that is still producing leaves and is over one year old, but it tries very hard to make seeds. I like to buy plants in August or September, and they will usually last me through the winter, but it very rarely gets below 45 degrees here in the winter, and so I leave them outside. Older plants don't have quite as much flavor, but they are better than none. You can usually get good fresh basil at Trader Joe's any time of year for a good price.

There are better ways of preserving basil - I keep it in salt and olive oil, and then it is ready for pesto. Some say that that is a dangerous way to preserve it, but I have not had problems with it. I don't freeze pesto after I have made it either.

Lars

You can also take a cutting from a healthy plant, put it in a glass/jar of water and it will root, doesn't take very long. You can then pot it in soil if you so desire.

jude, who has one she just potted not long ago.

when I "harvest" my basil, just strip off the leaves from the bottom couple of inches and put it in a vase/big glass of water by my sink. It will usually last a couple of weeks (change the water). . .I use from that when I cook. and it will "root" and you can start another pot!!

The more it's picked, the more it grows, and that's why I have so much. I do keep it in a glass of water too, but I picked two plastic grocery bags of basil and was hoping I cuold keep it in the fridge a few days. I have a friend who freezes her pesto, so I may try it.

Lars and LindaC, that's such good info -- I hadn't realized it was that sensitive to cold. Thank you.

Carolyn

I freeze my pesto in ice cube trays, works great! I didn't know that cold turned it black, either.

jude

I freeze my basil on the stems. I just wash it off and shove the whole stems into a gallon baggie, then keep adding to it until it's full. When I want to use it I just quickly take it out and snip the leaves into my pasta sauce. It doesn't turn black and just looks like it normally looks when cooked. I use the stems too and put them in the sauce just at the beginning and fish them out after I'm done. I add some basil as the sauce is cooking but just like fresh, I put most of it in just as it's done. I try to have at least five or six, gallon bags stuffed with basil for my winter cooking. You can just take the leaves off and skip the stems. I like the stems and I also like the flowers. Some years I bag the stems, leaves and flowers separately. It's not like fresh to use on salads and such, but it does work in cooked dishes and I've used it in salad dressing. You do want to work quickly and take out just what you're going to use each time. Don't leave the bag out to thaw or you will have a bag of soft basil. Not black, but.. soft. I'll have to take pics one of these days so ya'll can see it.

Coconut, I often do something similar to what you do. A quick wash of the basil on the stems. Shake off the excess water and pick off the leaves. I lay them on a baking sheet that's been lined with plastic wrap. Then into the freezer. Once frozen, I pop them into freezer bags. When I want bigger pieces of basil showing rather than the ground pesto style, I take out a couple of handfuls of the frozen leaves. Just a few quick whacks with my knife and toss into the sauce (or whatever). I like the look, especially in tomato sauces.