Can I plant broccoli next to onions

Yes, they are good companions.

They should do well together, but remember to rotate your crops, that way they will be less vunerable to pests and disease

I now have 6 broccoli plants but have no idea when I should harvest them. The tops of the plant have some yellow small flowers. There are other clusters coming from the inside of the bottom leaves.

Any suggestions would be appreciated. I live in North Texas.

Thanks.

If the heads are big enough to eat now is the time to cut them. The flowers can be removed but heads are a bit past prime. Use a knife to cut the heads and the plant will continue to produce 'side shoots', until it gets to hot for them.

Thank you Amigatec. I will now make daily trips to my vegetable garden and cut the ones that are now ready.