Given the (multi-pronged) question:

If I wanted to start growing hops, where should I look? How much would I want to grow for brewing once every couple months? Is it too late in the year to start?

Okeedokee. I’m gonna take these in reverse order.

It is not too late in the year to start, but it might be difficult to find rhizomes this late. They sell out pretty quickly each spring.

So. Another step back. Hops are typically grown from rhizomes rather than seeds. The reason why is because people typically grow the female hop plant only. Female plants are the ones that produce flowers for brewing - if you grow from seeds you have no guarantee that you will have female plants. Also, if you have both male and female hop plants, your female plants will produce seeds in the hop cones, which some say will negatively effect flavor.

So - hops are big. They can be grown in pots with some success (assuming a large pot), but hop vines can grow 18-25 feet in length. Each plant can produce 1 - 2 pounds of hops, assuming they have a good yield. Here in North Carolina I have yet to produce enough flowers to brew with, but it should be noted that I put in my hops right before entering into a huge drought, so I kinda got screwed on that. (I have new ones going this year that look great so far.) So, in answer to question two: ONE. But then you’re brewing with the same variety every time. Make your own judgment. Nobody says you have to harvest all the flowers, either.

The last thing to think about is that you’ll have to dry your hops some way, as well. You can use them fresh but they will impart a very different flavor (wouldn’t stop me), and will mold and rot in storage.

If you want to start, I’d look at FreshHops. They sell rhizomes and have a good section on growing them. I also found the book The Homebrewer’s Garden by Joe and Dennis Fisher to be really helpful. They also have a lot of information on herbs used for brewing which gave me far too many ideas.