Can you harvest brussels tops before the sprouts?
Some growers do remove the top of the plant to direct energy to the vegetable before picking Brussels sprouts.
My brussel sprouts did not fully mature and most are 1/2 to 3/4 inches in diameter. They look great and I assume can be eaten. Will they be bitter or should I just toss them and try again next year? Thank you.
They can be eaten, though you have a 50/50 chance that they will be more bitter or more sweet. If it was a problem with the plant that stunted it, it will likely be bitter. But, if was just that the plant did not have enough time to mature them, then they will be sweeter than you might be use to.
There is certainly no reason you can't pick the sprouts you have and try them to see how they taste. There are many different varieties, some might be smaller than others, yours might be smaller because of something in the growing of them, etc. Here's a little info on harvesting them: https://www.gardeningknowhow.com/edible/vegetables/brussels-sprouts/harvesting-brussel-sprouts.htm
and maybe some thoughts for next year: https://www.gardeningknowhow.com/edible/vegetables/brussels-sprouts/how-to-grow-brussel-sprouts.htm
Why have my plants not formed sprouts on the stalks? They only have a cluster at the top, and are about 18 inches tall.
They don't develop heads for the same reason they bolt, which is normally heat. In addition, there may be too much nitrogen in the soil, which is focusing more leafy growth. Adding additional phosphorus (like bone meal) may help offset this and aid in head development. This article may also help: https://www.gardeningknowhow.com/edible/vegetables/brussels-sprouts/brussel-sprouts-produce-loose-leafed-poorly-formed-heads.htm
I have rooted 3 brussel heads. How do I plant them?
Here is an article that you may find helpful: https://www.gardeningknowhow.com/edible/vegetables/brussels-sprouts/how-to-grow-brussel-sprouts.htm
After you have picked all the sprouts off the bush, do you pull out the plant or leave in to form more sprouts for a second or more harvest? Thank you.
Once you have harvested the sprouts, you can pull plant up. It will not produce any significant amount after it has been harvested.
What is the best way to feed the soil for Brussels sprouts?
Mix in some organic matter (like compost or manure) along with a complete, all-purpose fertilizer prior to planting to enrich the soil for optimal growth. If they are already in the ground, you can simply work in some compost around the plants.
I planted Brussels sprouts 2 years ago and have only got yellow flowers that turn into beans. Is this suppose to happen or did I get plants labeled Brussels sprouts and they are a different plant?
It sounds as if the plant has bolted and is probably not very tasty anymore. Crops like this need to be harvested before they bolt. To keep plants that are prone to bolting, they need to keep their soil cool. Mulch helps. This article will help: https://www.gardeningknowhow.com/edible/vegetables/vgen/what-is-bolting-what-it-means-when-a-plant-bolts.htm