Q.Bottlebrush Tree
I had three mature bottlebrush trees on my purchased property 3 years ago. Two died, one still remaining. Remaining one did not bloom last year, however, this year is beginning to blossom. It gets weekly watering, base covered with wood mulch, but I don’t know what kind of commercial fertilizer (besides compost) is required.
Does my existing tree require a male or female (?) companion for fertilization?
It does not need a companion to bloom and they are relatively maintenance free. Compost is the perfect fertilizer along with mulch and a healthy watering schedule. If you prefer to go the chemical route here is a link on what to choose;
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/giving-plants-a-boost-with-conventional-fertilizer.htm