I Planted Cosmos from Seed and They Are Now about 3 Feet Tall, with Not One Flower Yet. Any Ideas?
Cosmos, an excellent annual flower for color and cutting, requires about 7 weeks to come into first bloom from seed, and will then continue producing flowers until frost. Perhaps your plants aren’t quite mature enough for bloom. Check to see if the tips are beginning to form buds. Another possibility is that the plants are getting too much nitrogen fertilizer. Nitrogen, a necessary plant nutrient, helps to establish healthy green growth. However, if plants are fed too much when it’s time to set buds, flowering will be set back. Lots of green leaves but no flowers is often a symptom of over fertilization. One gardener who had this problem, was fertilizing with a dilute solution of a fertilizer containing 20-20-20 percentages, fertilizing each time the plants were watered. This means that the formula offers 20% nitrogen, 20% phosphorous, and 20% potassium. Lack of flowering in this case can probably be traced to over-application of nitrogen. Fertilizers with names like “bloom-more” are f
