Fertilizing Snowball Viburnum

Snowball viburnums produce orbs of frilly white flowers in spring, and the glossy green foliage provides summer-long color. The shrubs flower poorly if they aren't supplied with the right soil conditions or if you grow them in infertile beds. Annual fertilization replenishes the phosphorous in the soil, which is the main nutrient the plant needs for producing an abundance of spring blooms. Soil testing with a kit from a garden store or extension office provides a more specific guide to the shrub's nutrient needs.

Soil test kit
Wood ashes or lime
5-10-5 fertilizer
Compost

Instructions

- 1
  Take a soil sample from the viburnum bed, and follow the instructions specific to your soil testing kit. The test can determine the soil pH level. Viburnums require a pH near 7.0. Testing the soil every two years is usually sufficient.
- 2
  Sprinkle wood ashes or agricultural lime over the soil around the shrub if the soil pH is too low. Use the amount of ashes or lime recommended by the soil test results.
- 3
  Apply a 5-10-5 fertilizer blend or other high phosphorous fertilizer after the snowball viburnum finishes its flowering cycle. High nitrogen fertilizers can inhibit flowering the following year. Apply about half a cup of fertilizer by sprinkling it in a ring around the trunk about 6 inches out from the base of the shrub.
- 4
  Spread a 1-inch layer of compost over the soil after fertilizing. The compost improves drainage and organic matter content around the bush as it works into the soil.

How to Grow Korean Spice

How to Start a Japanese Juniper From a Branch

Shrubs