Watering schedule

How often to water Arborvitae (Thuja occidentalis) — the schedule

Also called arborvitae, eastern arborvitae, American arborvitae, white cedar, eastern white cedar, northern white cedar, tree of life.

More about arborvitae

Watering at a glance

Base rhythm	Deeply once or twice a week for the first 1-2 growing seasons, then mainly in droughts
Spring / summer	Spring and summer: water when the top of the soil is dry to roughly a knuckle deep — typically once or twice a week.
Autumn	Autumn: growth slows, so stretch the interval and let it dry a little more between waterings.
Winter	Winter: water noticeably less — often half as often — because low light and dormancy slow water use right down.
Light	Direct sun (at least 4-6 hours)

About Arborvitae

Thuja occidentalis · also called arborvitae, eastern arborvitae · houseplant

Arborvitae is a hardy evergreen conifer grown outdoors for hedging, screening and in large containers. It wants full sun, deep well-drained soil and even moisture while establishing. It is not on the ASPCA list, but its foliage and oils contain thujone — a neurotoxin — so treat it as toxic to pets and livestock and verify any exposure with your vet.

Ideal humidity: Outdoor ambient

Watch for — Winter burn / foliage bronzing: Cold, drying winds and winter sun pull moisture from the evergreen foliage faster than frozen roots can replace it, scorching it brown, especially on young or exposed plants.

The watering schedule, season by season

Arborvitae likes a soak-then-partly-dry rhythm — let the top of the soil dry before watering again, and never leave it standing in water. The base rhythm for arborvitae is deeply once or twice a week for the first 1-2 growing seasons, then mainly in droughts, but the real interval moves with the season, the light and the pot — so treat the figures below as a starting point and always confirm with the plant itself.

Spring & summer (active growth): Spring and summer: water when the top of the soil is dry to roughly a knuckle deep — typically once or twice a week.
Autumn (slowing down): Autumn: growth slows, so stretch the interval and let it dry a little more between waterings.
Winter (rest / dormancy): Winter: water noticeably less — often half as often — because low light and dormancy slow water use right down.

Newly planted arborvitae need consistent, deep watering while roots establish; let the surface dry slightly between soakings but never let the rootball dry out, as drought stress causes browning. Established plants are fairly drought-tolerant but still benefit from a deep soak in prolonged dry spells. Containers dry far faster and may need watering every few days in summer.

Want this turned into a live reminder that adjusts to your home and the weather? The Growli watering calculator takes your pot size, light and season and returns a starting interval for arborvitae in seconds.

How to tell arborvitae needs water

A calendar is the worst way to water arborvitae. Check the plant and the soil instead — for this species, look for these signals in order:

The top 2-3 cm of soil is dry to the touch (or a knuckle-deep finger test comes back dry).
Lifting the pot, it feels distinctly light.
Leaves droop slightly or lose a little of their gloss just before they truly need water.

The most reliable single check is the first one on that list. When two signals agree, water; when they disagree, wait a day and look again — under-watering arborvitae for a day is almost always safer than over-watering it.

Overwatering vs underwatering arborvitae

The two failure modes can look alike at a glance, so check the soil weight and wetness before you decide. For arborvitae specifically:

Signs you are overwatering

Yellowing lower leaves and a pot that stays wet and heavy for days.
Soft, brown, mushy stems or a sour soil smell — root rot.
Fungus gnats breeding in permanently damp soil.

Signs you are underwatering

Drooping, curling leaves with crispy brown edges that perk up after watering.
The rootball shrinks away from the pot and water runs straight down the sides.
Slow growth and a generally tired, washed-out look.

Watering arborvitae on a fixed weekly calendar regardless of season is the most common mistake — in dim winter light the same routine drowns it. Check the soil, not the date.

Water quality notes

Tap water is generally fine for arborvitae. If your water is very hard and you see brown leaf tips, switch to filtered or rainwater.

Seasonal and environmental adjusters

Every figure above shifts with the conditions in your home. For arborvitae, the levers that matter most are:

More light and warmth speed drying; the brighter the spot, the shorter the real interval.
Pot size and material matter — small terracotta pots dry far faster than large glazed or plastic ones.
Lifting the pot to feel its weight is more reliable than any calendar for judging when to water.

Pot choice is part of this too — work out the right size with the pot size calculator, since a pot that is too big stays wet long enough to rot the roots of arborvitae.

Arborvitae watering — frequently asked questions

How often should I water arborvitae?

Water arborvitae deeply once or twice a week for the first 1-2 growing seasons, then mainly in droughts. Spring and summer: water when the top of the soil is dry to roughly a knuckle deep — typically once or twice a week. Winter: water noticeably less — often half as often — because low light and dormancy slow water use right down.

How do I know when arborvitae needs water?

The top 2-3 cm of soil is dry to the touch (or a knuckle-deep finger test comes back dry). Lifting the pot, it feels distinctly light. Leaves droop slightly or lose a little of their gloss just before they truly need water. The single most reliable test for arborvitae is the first signal on that list — checking the soil or the plant directly always beats watering by the calendar.

What does an overwatered arborvitae look like?

Yellowing lower leaves and a pot that stays wet and heavy for days. Soft, brown, mushy stems or a sour soil smell — root rot. Fungus gnats breeding in permanently damp soil. Watering arborvitae on a fixed weekly calendar regardless of season is the most common mistake — in dim winter light the same routine drowns it. Check the soil, not the date.

What are the signs of an underwatered arborvitae?

Drooping, curling leaves with crispy brown edges that perk up after watering. The rootball shrinks away from the pot and water runs straight down the sides. Slow growth and a generally tired, washed-out look.

Can I use tap water on arborvitae?