Arborvitae are the most-planted privacy trees in Pennsylvania, and the most complained about, usually by the same people. The difference between a lush green wall and a row of deer-stripped brown skeletons comes down to three decisions made on planting day: which variety, how far apart, and whether the deer situation was taken seriously. Here is how to get all three right.
Two Arborvitae, Two Different Jobs
‘Emerald Green’ is the narrow one, a cultivar of our native northern white-cedar (Thuja occidentalis) that tops out around 12-15 feet tall and 3-4 feet wide. It is the right pick for tight property lines, foundation corners, and formal hedges, growing a modest foot or so a year. The Arbor Day profile covers the parent species, which in the wild can live for centuries.
‘Green Giant’ is the big hybrid: 3 feet a year, 40-60 feet at maturity, 12-18 feet wide. It is the one we name every time someone asks about a fast, durable screen, including in our guide to the fastest growing trees. It needs room, and people routinely plant it where a 60-foot tree cannot be, so measure first.
The Deer Problem, First
In most of Central PA, deer eat ‘Emerald Green’ arborvitae the way kids eat fries. A hungry winter herd will strip every needle from the ground to 5 feet and leave you a row of green lollipops on brown sticks, and arborvitae are slow to refill browsed wood. ‘Green Giant’ is noticeably less palatable, which is a real reason to choose it beyond speed, but no arborvitae is deer-proof. If your yard hosts deer every winter, either commit to repellent spraying and netting for the first several years or plant Norway spruce instead, which deer mostly leave alone.
Planting a Screen That Fills In
Full sun grows a dense arborvitae; heavy shade grows a thin, sulking one. Six hours of direct light is the working minimum. Space ‘Emerald Green’ 3-4 feet apart for a hedge, and ‘Green Giant’ 8-12 feet apart, or 5-6 feet if you need the screen closed fast and are willing to thin later. Resist the urge to plant tight against the property line, because half the mature width will hang over it.
The planting itself follows the same rules as any tree, walked through in our 9-step planting guide: hole twice the width of the root ball, root flare at grade, native soil backfill, a deep watering, and 2-3 inches of mulch kept off the trunk. Arborvitae roots run shallow, so water weekly through the first two growing seasons and give the row a deep soak before the ground freezes each fall. Dry roots going into winter are the main cause of the browned, burned look screens wear in March.
Keeping It Green
Bagworms are the top arborvitae pest here: spindle-shaped bags of dead foliage hanging like ornaments, each one a caterpillar eating your hedge. Handpick them fall through early spring before eggs hatch. Spider mites bronze the foliage during hot dry spells. Wet snow and ice splay multi-leader trees apart, so shake heavy snow off gently the same day and buy single-leader plants when you can. Inner foliage turning brown in fall is normal shed, not disease.
Prune lightly and stay out of the interior: like most conifers, arborvitae will not resprout from bare old wood, so a hedge sheared too deep stays hollow. Trim the outer green growth only, ideally in early summer, and keep up with it rather than trying to reclaim an overgrown row in one brutal cut.
The Long View
A well-sited arborvitae screen is a decades-long asset that gets better every year. A badly sited one is a future removal job, and we grind out enough dead ‘Emerald Green’ rows to say that with confidence. Sun, spacing, water the first two years, and a plan for deer: get those four right and the green wall takes care of itself.
