How to do it is not a difficult. Just get a sharp knife and give them a quick slice a few inches below the head. When to do it is the critical part. I planted starts just about 45 days ago, but the weather has been so hot, I've been watching them closely. I checked them this morning, and realized I couldn't wait any longer. How do you know when to cut them?

Here's a picture of my first harvest.

How did I know they were ready?

As far as I know there is only one definitive indicator. The size of the buds. I did a lot of web searching for time to harvest. I got so much conflicting information the only conclusion is there is no really good way to tell by the calendar. As an example, one website says, "Typically a slow-growing plant, broccoli can take 50 to 100 days to reach maturity, though growing times differ among broccoli varieties." Time to to first harvest for me - about 30 days. Glad I didn't wait!

Almost Too Late
 Nice and Tight

broccoli overripe1358x320

broccoli tighthead1396x320

Notice the yellow starting to show on the one on the left. And the buds are looking larger and less well defined. The one on the right is perfect. It will stay tight and ready for quite a while when the weather is cool, but warm weather makes them want to bolt.

Head size doesn't matter. 

(Ok, that was a cheap shot. I admit it.)

000broccoli

If you have a floret that looks like the one on the right, it's ok to cut it. It will taste great no matter how small. As long as the flowers look tight like this you can delay cutting and let the head get bigger. If the weather is warm, check daily. Give it time to grow. 

The thing to watch for is the flowers getting bigger, and starting to show some yellow and the buds looking less compact. When the yellow shows they are about to open up and will not be great on the table.

Then, who cares about the estimated time?

The estimated time to harvest is mostly important if you have a good size space, and can plant several varieties for continuous harvest in multiple seasons. Or a single variety and plant several weeks apart.  Even a single variety will put out for several months and allow you to keep harvesting as you need to. 

So Just cut it off when you are ready. There will be more.

But, What IF, they already flowered?

Don't worry, the flowers are edible raw or cooked. They just taste different (still good I think), but people might not recognize them as broccoli! Maybe someone has some recipes for broccoli flowers?