I have it, unfortunately, in my field. This is a bad plant (noxious weed)! It is very invasive and can be very hard to get rid of with seeds staying viable for 80 years! It crowds native species out in many (most?) environments.

I have several..and I mean SEVERAL that I simply love!!! I garden on a very large scale and they're scattered all about. For me, they aren't invasive at all and I even get a few babies from the pale yellow ones. (I wish that I could propagate some of the deep yellow (Scottish Broom??) Also, they have and extended bloom period.

The reasons I don't like it are...

It's listed as a noxious weed by almost every state and in almost every noxious weed list. (This alone is reason not to every try to have any more.)

Many conservation groups (The Nature Conservancy, which I am a member, for example) are having to spend a lot of money to try to keep it from complete devastating native plants. This species tends to form monolithic colonies that replace native vegetation.

Not only do seeds stay viable for up to 80 years, but they are also poisonous to livestock. The plant can also cause alergic reaction and skin irritation.

When growing in a field, it's hard to mow. It actually looks like it wouldn't be because it appears less dense than alot of stuff, but apparently the stems are tough because it can choke out even a very powerful mower that usually will tackle about anything.

It also looks ungly in a field. It's the ugliest weed in my field. It sticks out and makes the field look aweful.

On the other hand...

Some commercially available varieties are not invasive. So, if you want the stuff, please make sure you are doing the environment and your neighbors a favor and get a non-invasive cultivar.

Thanks for the info, Brandon. I'm sure that I have the non-invasive variety that you mentioned. (I hope:):). Sorry about your field.