As you care for your Colorado four o'clock, recall that this plant does not need a lot of fertilizer each year and will begin to suffer if it receives too much. Firstly, any overfertilized plant runs the risk of fertilizer burn, a condition in which excessive amounts of fertilizer draw nutrients and moisture out of the plant's roots, causing its decline. Also, overfertilizing a Colorado four o'clock is also a way of weakening your plant and making disease far more likely. There is also a potential that overfertilization could cause your Colorado four o'clock to flower less or not at all, which is a significant detriment considering the blooms of this plant are what make it so valuable and sought after by so many gardeners.