I want to fertilize my Juniper hedge which is about 20 ft. long along my deck. I have a Schultz fertilizer for Camellia, Azalea, Juniper, etc. that is 33-11-11. I have a Hy-Yield fertilizer for the same list of plants, this is 4-8-8. Now if 33-11-11 is good for my plants then the 4-8-8 (a polar opposite) must be bad. I also have a Woodburn Fertilizer for the same list of plants that is 5-6-7. This is all very confusing. So, if all three above are suitable for the Juniper, why isn’t 16-16-16 just as good, or possibly better for all plants? This is extremely confusing. I hope you can shed some light on the proper care for my Juniper. Thank you, Earle Culbertson
The only reason one should fertilize a woody hedge is if the soil is short on one or several fertilizer elements needed by the hedge. In general, the clay-based soils in Clackamas County are sufficient for sustaining a healthy woody hedge such as your arborvitae.
Often, people want to fertilize because a hedge doesn’t appear to be healthy. The preferred solution, though, is to discover why the hedge is off-color and possibly failing. Among the potential reasons are insufficient or excess water. (Arborvitae should be watered at least monthly during the dry months; sprinkler irrigation for the lawn is not adequate.) Fertilizing stressed woody plants only causes further stress because the plants must use reserves to push new growth.
Another unwise decision is to fertilize a young hedge to make it grow more rapidly. In this case, the new f=growth may not be self-supporting, plus the weak stem may be more likely to break with the wind. Slow and easy is the best guideline for a hedge’s growth activities. To further assist the arborvitae, maintain an organic mulch on the soil along the hedgerow with a 3- to 4-inch deep layer of bark chips or 2-inch deep bark dust.
The bottom line is that fertilizer should be applied only after a professional laboratory tests the soil and, then, suggests the appropriate kinds and amounts of elements to apply to correct a deficiency. You can obtain a professional soil test from contact A & L Western Agricultural Laboratories (503-968-9225) in nearby Tigard. Phone to determine how they suggest you sample and package the soil, then either take the sample in or mail it. Tell the lab the test is for an arborvitae hedge in a home landscape. the cost of a complete basic soil test is about $35 or so.