Galphinia is a native of Mexico, so right away you know that this is another of my beloved tough plants. It loves warmth and sun and keeps blooming throughout the year. It can take partial sun but it will probably means less flowering. The internet says it likes fertile soil but I find it grows fine in my sandy soil. Once established the plant needs little watering although it is helpful during a hot dry summer.
Galphinia is a shrub that grows very fast. Make sure you give it some room to grow as it naturally can grow several feet high and wide. It develops low branches that fill in as a ground cover. If you do not want it to grow so big you will need to keep up with the trimming back. I give mine a severe haircut about every year and pinch off the tips to shape it during the year. Pinching does delay the flowers blooming though. I decided last year to cut off all of the lower growth and turn the shrub into a full head on a stand shape so that I could have other stuff below it.
Galphinia is a hardy plant and I have had no problems with disease or pests. Babies can be grown from seeds or cuttings. I know I have done so many years ago, but I do not remember it as an easy plant to propagate, so it may take some experimenting for the home gardener. I do love this plant for its persistent show of color in the garden and for its easy care. It is not so good as a cut flower for flower arrangements unfortunately. In Mexico it is used in several ways in traditional medicines.