This is the time of year when you notice that your geraniums have suddenly stopped blooming. If you look closely you might discover some holes in the buds. Your plants have fallen victim to tobacco budworms.Shown here, tobacco budworm caterpillars chew into the flower buds, the buds fail to open and your geranium stops blooming. Budworm will also damage petunias and penstemon, causing the plant to stop blooming. You can control budworm by applying products containing Bt (Bacillus thuringiensis).
You can control budworm by applying products containing Bt (bacillus thuringiensis). Dipel is a dust which can be applied directly to the plant. Thuricide is a concentrate, which is mixed with water and sprayed on your plants. Dipel and Thuricide are biological controls that get rid of budworm.
Allowing spent flowers to remain on the plant can also slow down bloom production. You want to remove flowers as soon as they begin to fade, to encourage new flower buds. This is known as deadheading. Deadheading is the process of removing the flowers as they begin to fade. You want to remove the flower petals as well as the stem it’s connected to.
Follow the flower stem back to the main stem and clip it off, using a sharp pair of garden scissors. Check the plant and remove any fading flower clusters.
By keeping up on deadheading, watering regularly and fertilizing with a well-balanced fertilizer such as Fertilome 20-20-20, your geraniums will stay healthy and blooming for the rest of the season.