Sky Pencils Looking Sad
Hi! We live in the Fairfield subdevision of Newark. We have to sky pencils in our front garden and they're not doing well. The golden pillars and other perennials are doing great. I fertilize each fall with Holly tone. The pH is 7.5 and moisture is 3 (scale 1-10). Id guess that the area is part sun to full sun. The bed is on the north side of our house. We have a Mister Landscaper system that runs for 15min every 3 days with a rain sensor. This bed has landscape fabric and pine bark. Last fall I turned off the misters around the sky pencils for fear of root rot. They've lookd this bad for almost 2 years now. The plants are 4 years old. Any help would be greatly appreciated!!!
As you mentioned Sky Pencils are very susceptible to root rot. We have had a very wet spring and humid and hot 2018 so far and also had a significant amount of rain in 2017 as well as very humid and hot weather. The winters have had some very cold periods as well but that by itself should not be a problem.
I cannot tell from your photo but it is important that the crown of the plant not be covered with soil. If this crown is under the landscape fabric and the mulch and in addition may or may not have soil over the crown it may be kept too wet.
I also can see that there is evidence of plant hoppers on many of the branches that are browning out. They do not usually kill the tree unless they are very numerous. Another common pest on pencil trees is spider mites. Can’t tell if they are present from the picture so suggest that you take a branch or two with both brown and green sections to the New Castle County Extension Office prepared per the information below. Make sure the branches selected have the white substance on them.
Plant Submission Guidelines: Examine plants carefully and select leaves or plant parts showing a range of symptoms from mild to severe. Often there is a transition zone between diseased and healthy that may provide the best sample. Select enough material to work with, for example several shoots or branches. Try to collect a sample prior to the application of any pesticides.
Place the sample between paper towels or in a paper bag. Then place sample in a Ziploc or other plastic bag and label the outside with a name and date written in permanent marker. Refrigerate the sample, or store in a cool location out of direct sunlight, until submission. Many samples deteriorate rapidly.
Bring your sample to the New Castle County Extension Office and visit the “drop-off station” in our hallway to fill out the appropriate form(s) and leave your sample for evaluation. If necessary, the Extension Educator will coordinate with the Plant Diagnostic Clinic for assistance. A Master Gardener or Extension Educator will call you about your sample within 7 to 10 business days. Call 302-831-8862 for directions.