How-To Keep Your Boxwoods Happy & Healthy

Published by Bucks Country Gardens in Lawn & GardenPlants

Plants can get pests and some are more susceptible than others. There is no need to give up though, because pests are easy to treat, especially when you are proactive in monitoring your plants. Boxwood pests are very common. Here we will focus on the Boxwood shrubs (commonly used in Pennsylvania landscaping) and how to keep them happy and healthy.

All About Boxwoods

In a casual or formal setting, Boxwoods are always great for adorning your landscape because of their versatility – rich green, strong shape, adds structure. Boxwoods are ideal as hedges, edgers and low hedgers, punctuation points, topiaries, or even in containers. Boxwoods vary in size, shape, characteristics, growth rates, and hardiness. They are also deer-resistant, which is a must in this area. Shop our Nursery for your next Boxwood!

3 Pests to Look Out For

Depending on conditions, Boxwoods can be susceptible to multiple pests. Here are three pests to keep an eye out for…

Boxwood Leafminer: Key pest of Pennsylvania plantings of Boxwood – the eggs are white to transparent and hatch to small, whitish to lemon-yellow, and 3 mm long larvae. Adults are small, yellow to orange-red, 2.5 mm gnat-like flies. The larva spends its winter nestled in the shrubbery – much like hibernation. During the spring, adults emerge, mate, and create nests. Larvae continue to grow and feed on leaves through the remainder of summer.

Boxwood Mite: Common and widespread pest – spends its winter in the egg stage. The lemon-yellow eggs hatch from late April through early May. Eggs hatch in 6-10 days and the yellowish-green larvae start to feed on the plant they are in. Adults are green to yellowish-brown and may live 2-5 weeks. This insect completes one generation in 18 to 21 days and at least eight generations are produced each year.

Boxwood Psyllid: Common pest of Boxwood – the eggs are small, orange, and spindle-shaped. Nymphs (young adults) are distinguishable from other insects that attack Boxwoods, in that they have fang-like waxy white mouths which help them feed on the plant. Adults are 3 mm long and are a greenish color. The pest spends its winter in the egg stage. Eggs are laid during early summer and hatch as soon as buds begin to open in early spring. Nymphs develop on newly expending foliage and mature to adults in early June. One generation occurs each year.

How to Treat Your Boxwoods

It’s all about monitoring your plants! Check the leaf hydration, color, and if there are any nests. These three types of pests target different areas of the plant, so each one will reveal special appearances. It also depends on your location in Pennsylvania and how you care for the plant. Treating Boxwoods is as simple as a trip to our Garden Pharmacy. We have a great selection of effective insect control products to control and treat all stages of insect life.

Here’s what to look out for and how/when to treat:

Leafminers- Leaves will look discolored or may become puffy, swollen, or ragged-looking with occasional dead twigs. Apply Bonide Systemic Insect Control and Bonide Malathion Insect Control during May. For an organic option, use Bo-Neem Fungicide-Miticide-Insecticide.

Mites- Boxwood appears as mottling, followed by yellowing and browning near lower part of the leaf. Apply All Seasons Horticultural Spray Oil during the winter egg stage. Infested plants should also be treated with Bonide Malathion Insect Control when active life stages of the pest are present. For an organic option, use Bo-Neem Fungicide-Miticide-Insecticide.

Psyllids- Damage is noticeable when leaves show a cupping effect. Occasionally young twig growth is affected. Treat with Bonide Systemic Insect Control and All Seasons Horticultural Spray Oil (for immature stage) when nymphs are present in early May. For an organic option, use Bo-Neem Fungicide-Miticide-Insecticide.

Depending on the severity of the infection and your environment, it could take a little while to get your plant back to normal. There also is a small chance after treatment that the pests will return. Treat them again as you did with your first sighting.

Don’t Give Up!

If you are unsure about whether your Boxwoods have pests or if you are treating your plants correctly, bring in samples to our Garden Pharmacy! Take a small sample from the area you’re concerned about and pack it up in a sealed plastic bag. The experts at Bucks Country Gardens will be happy to diagnose any problems you are having. No question is wrong. We are here to make sure your plants are happy and healthy!

As an alternative to planting Boxwoods, plant Japanese Hollies. They share similar compact form and green leafy foliage – great for front space structure. For more information stop in and get expert advice on our many shrub options.


Written by:
David Jones | Horticulturist, Customer Service Specialist, & ISA Certified Arborist
Heather Fesmire | Digital Marketing Assistant
Material from Penn State University’s “Boxwoods for Pennsylvania Landscapes”