I purchased some more cleome this year, and put them

In a sunny spot but they aren't as near as tall as others I have. They're like 2 feet tall where the others are almost 4 feet tall. The bloom looks the same just a different color. I thought even the dwarf type got at least 3 foot. Any ideas?

My other question is do cleome also come back from roots? I know they reseed, but aside from reseeding will the plant come back from roots as well?

Thanks so much.