According to Iowa State University Extension, there are over 150 species of viburnums. Viburnums are shrubs that can grow as small as 2 feet, or as large as 30 feet. They are often used to landscape homes. Viburnums produce small red, purple or blue fruits. Some of these fruits are poisonous and should not be eaten. Although viburnums can grow in almost any type of soil, you should fertilize them once per year so that they get a few added nutrients.
Choose a date in the early spring to fertilize your viburnums, and then mark your calendar so you don't forget.
Dress in long clothing the day you plan on using the fertilizer. It contains harsh chemicals and can damage your skin.
Wear protective gear, such as goggles, gloves and a mask. Again, this is to protect you from the chemicals in the fertilizer.
Read the packaging label for a 10-18-12 (nitrogen-phosphorus-potassium) slow-release fertilizer. The brand you use will most likely require you to mix the fertilizer with water before you apply it. Merrifield Garden Center of Virginia recommends this type of fertilizer for viburnums.
Apply the fertilizer around your viburnums as directed on the packaging label.