What Fertilizer Is Good for a Golden Euonymus?
The evergreen euonymus is a common plant used in hedges across the U.S. The most popular cultivar (Euonymus japonicus ‘Aureomarginatus,’ USDA hardiness zones 6 to 9) has variegated yellow-green leaves that give the plant its "golden euonymus" nickname.
As with most woody evergreen shrubs, euonymus (which is not only its botanical name but also its common name) requires regular maintenance, fertilizer and pruning—but the most important aspect of this shrub’s care is to ensure proper pH, as it is intolerant of too-alkaline soils.
About Euonymus Shrubs
While the most popular and available golden euonymus shrubs are cultivars of the Japanese euonymus, Euonymus japonicus, multiple other species exist, including wintercreeper (Euonymus fortunei 'Emerald n Gold') and deciduous groundcovers such as Euonymus obovatus.
All species prefer full sun but can benefit from some partial shade during hot afternoons to limit sun exposure. Like most plants, they require well-draining soil.
These are large landscape shrubs, typically reaching 10 to 15 feet high and 5 to 8 feet wide, but they lend themselves to heavy pruning and can be maintained.
Fertilizing Golden Euonymus
While landscape plants like golden euonymus are fairly low maintenance, attention to key aspects of its care will help ensure a healthy shrub.
First, the correct soil pH is important for euonymus shrubs, because soil types that are too alkaline can result in chlorosis, a yellowing of the leaves from iron deficiencies. To ensure the proper environment, get a soil test, available from most nurseries or your local university extension office.
The ideal pH for euonymus is 6.5 to 7.0, reports Mississippi State University. If your test reveals an alkaline pH higher than 7.0, add sulfur to lower the pH and a liquid, concentrated form of iron and zinc to provide the missing micronutrients.
Euonymus shrubs can live for years and are in it for the long haul. Woody trees and shrubs grow best when provided high-nitrogen fertilizers rather than balanced fertilizers. This is because most soils retain phosphorus and potassium over time, while nitrogen can be depleted—but a soil test will tell you for sure.
In most cases, you are looking for a granular fertilizer mixture with an NPK ratio such as 4-1-1, 15-5-5 or 24-8-16, in which the first number represents the percentage of nitrogen, the second phosphorus, and the third potassium.
Ideally, apply fertilizer in late August through September so that the nitrogen will be stored in the soil and ready to support spring growth. If you miss the fall window, apply in early spring, just before the new year’s flush of growth. Follow the product manufacturer’s directions regarding how much to apply.
If fertilized with an excess of nitrogen, euonymus can revert to a green form rather than maintaining a variegated appearance, so if this begins to occur, back off on the nitrogen for a year.
Look for slow-release granular fertilizer to ensure a slow, steady uptake of nutrients and uniform growth. Organic fertilizers take longer to break down and are a good bet to combat poor soil and build up fertility in the long run.
I garden in the Pacific North west, previously Hawaii where I had an avocado orchard. I have a Master Gardeners certificate here in Eugene, Oregon.