Potted Arborvitae Care: Watering, Browning, and Winter Prep for Baltimore Decks

Arborvitae in Containers: The "Water by Weight" Method and Winter Survival

Two 5-6 ft arborvitae on a Baltimore deck since May. Lower browning + watering confusion = classic container conifer issues.

Watering Protocol (Critical)

• DAILY watering = too much. Causes root rot.
• Weekly deep soak: Water until draining freely. Let drain 10 min.
• Check before watering: Finger 2 inches deep. Dry = water. Moist = wait.
• Weight method: Learn pot weight wet vs. dry. Water when significantly lighter.

Browning Diagnosis

• Inner/lower browning: Normal seasonal needle drop. Conifers shed oldest needles annually.
• Tip browning: Drought stress or salt burn
• Overall bronze: Winter desiccation or spider mites

Spider Mite Check

Tap branch over white paper. Tiny moving dots = mites. Morning jet-spray weekly disrupts them. They hate humidity.

Winter Prep (Baltimore Zone 7a)

• Water deeply before ground freezes
• Antidesiccant spray (Wilt-Pruf) in late Nov + Jan
• Wrap pots: bubble wrap + burlap. Cluster together.
• Brush snow OFF—weight breaks branches
• Water monthly during thaws

Long-Term Reality

Arborvitae eventually need ground planting or very large containers (25+ gal) with root pruning every 3 years. For now, fix the watering.