Thuja growth rates vary enormously depending on the species and cultivar, from as little as a few inches per year for dwarf forms to three feet or more annually for vigorous varieties like ‘Green Giant.’ That range makes Thuja one of the most versatile evergreen genera for landscaping, but it also means the answer to “how fast does Thuja grow?” depends heavily on which Thuja you are talking about and the conditions you give it.
Growth Rates by Species
The genus Thuja contains five species, but only two are widely planted in North American and European gardens: Thuja occidentalis (eastern arborvitae or eastern white cedar) and Thuja plicata (western red cedar). A popular hybrid, Thuja ‘Green Giant’ (a cross between T. plicata and T. standishii), rounds out the trio that most homeowners encounter. Each behaves differently.
Thuja occidentalis is the slower grower of the group. Standard-sized varieties typically add somewhere around 12 to 24 inches of height per year once established, though the popular columnar cultivar ‘Smaragd’ (sold as Emerald Green in North America) tends toward the lower end of that range. Many dwarf occidentalis selections grow less than six inches annually, which is the entire point of choosing them for foundation plantings or small hedges.
Thuja plicata grows faster in the wild and in cultivation. According to USDA Forest Service data, dominant trees in pure second-growth stands on moist sites in western Washington average about half a meter (roughly 20 inches) of height growth per year over decades, and annual radial trunk increments on the best coastal sites in British Columbia reach 10 to 20 millimeters.1United States Department of Agriculture (USDA) Forest Service. Western Redcedar (Thuja plicata Donn ex D. Don) Those are mature forest trees, though, not newly planted landscaping specimens. Young T. plicata can put on considerably more height in a single season under good garden conditions.
Thuja ‘Green Giant’ is the speed champion. In favorable climates (roughly USDA zones 5 through 8), established plants regularly add three feet of height per year, and some growers report even more during peak growing seasons. That pace is why ‘Green Giant’ dominates the privacy-screen market. It can go from a nursery liner to a 15-foot tree in about five years, making it one of the fastest-growing evergreen options available to homeowners.
Why Growth Rates Slow Down Over Time
Thuja growth is not constant from year to year. A newly planted tree in its first season may seem sluggish because its root system is still establishing. Energy goes underground before it goes upward. By the second or third year the roots have spread enough to support vigorous top growth, and that is when you see the headline annual gains. For ‘Green Giant,’ years two through about ten are typically the fastest.
Once a Thuja reaches its mature canopy height, vertical growth tapers off. A ‘Green Giant’ that was adding three feet a year at age five may slow to a foot or less by age 15 or 20, and eventually only add a few inches as it fills out laterally. USDA silvicultural records for wild Thuja plicata illustrate this pattern on a longer time scale: young western red cedars on good coastal sites initially grow as tall as or taller than Douglas-fir and western hemlock seedlings, but they are overtaken by Douglas-fir around age 10 and by western hemlock by age 15, as the Thuja’s pace of vertical extension declines.1United States Department of Agriculture (USDA) Forest Service. Western Redcedar (Thuja plicata Donn ex D. Don) The same deceleration applies in the garden, just on a compressed scale.
Water Is the Single Biggest Growth Driver
If you want a Thuja to grow at the top of its potential rate, consistent moisture is the single most important factor. All Thuja species evolved in regions with plentiful rainfall. Western red cedar is native to the Pacific Northwest’s wet maritime forests, and eastern arborvitae naturally occurs in swampy lowlands and along lakeshores in the Great Lakes and northeastern regions. Both species grow fastest on moist, well-drained soils and slow down substantially when water is limited.
Research on how Thuja occidentalis handles drought sheds light on why dry conditions stunt growth. When six-year-old eastern white cedars were exposed to repeated water-stress cycles, moderately stressed trees cut their cumulative water loss by about 50 percent compared to well-watered controls.2PubMed. Mechanisms of drought response in Thuja occidentalis L. I. Water stress conditioning and osmotic adjustment Even mildly stressed trees reduced water use by roughly 35 percent. That dramatic shutdown in transpiration is a survival mechanism, but it comes at the cost of photosynthesis and growth. Once a Thuja closes its stomata to conserve water, it is no longer taking in the carbon dioxide it needs to build new tissue.
A follow-up experiment on the same species found that moderately drought-conditioned trees maintained higher internal water pressures during a severe drought, with transpiration rates about 38 percent lower than non-conditioned trees.3PubMed. Mechanisms of drought response in Thuja occidentalis L. II. Post-conditioning water stress and stress relief In plain terms, a Thuja that has been through repeated dry spells learns to conserve water more aggressively, which helps it survive but does not help it grow. If you have planted a hedge and want the fastest possible fill-in, do not let the soil dry out deeply between waterings during the first few growing seasons.
Does More Fertilizer Mean Faster Growth?
Many gardeners assume that adding extra nitrogen is the key to pushing Thuja growth rates higher. The reality is less straightforward. A study comparing different nitrogen rates and application methods for field-grown Thuja occidentalis found that height growth was not significantly affected by nitrogen rate or by how the fertilizer was delivered (fertigation versus granular).4Canadian Journal of Soil Science. Nitrogen Management Strategies for Field-grown Thuja occidentalis: Comparison of Fertigation and Granular Fertilization In other words, dumping more nitrogen on your arborvitae hedge is unlikely to make it grow meaningfully taller in a given year.
That does not mean fertility is irrelevant. A Thuja planted in genuinely nutrient-poor soil can look thin and pale, and correcting a true deficiency will improve overall health and color. But once a baseline level of nutrition is present, the tree’s growth rate appears to be limited more by water availability and genetics than by extra fertilizer. Over-fertilizing, on the other hand, carries real risks: salt buildup can damage roots, and excess nitrogen can push soft, weak growth that is more vulnerable to winter burn and pest damage.
There is an interesting contrast for western red cedar. Research on Thuja plicata seedlings suggested that higher soil nitrogen levels, combined with warmer temperatures, positively influenced growth.5Nature Precedings. The effect of temperature, soil nitrogen and gastropods on Thuja plicata growth and reproduction The species may be somewhat more responsive to nitrogen than its eastern cousin, or the seedling stage may simply be more responsive than an established tree. Either way, nitrogen alone is not a growth shortcut for most garden Thuja.
How Planting Environment Changes Everything
Where you put your Thuja matters almost as much as which variety you choose. A study examining Thuja occidentalis in different urban landscaping settings found dramatic differences in tree vitality. Trees growing in parks, private gardens, and country houses showed no signs of weakening. Trees in courtyard areas of a city showed weakened vitality. And trees planted along highways and city streets were rated as strongly weakened or oppressed.6Вестник Бурятской государственной сельскохозяйственной академии имени В. Р. Филиппова. THUJA OCCIDENTALIS
The pattern makes intuitive sense. Roadside plantings face a combination of stresses that garden trees do not: road salt spray in winter, compacted and often alkaline soils, reflected heat from pavement, restricted root zones, and air pollution. Each of those individually slows growth; together they can reduce a Thuja to a fraction of its potential size and vigor. If you have seen scraggy, brown-tipped arborvitae lining a parking lot and wondered whether the species is just unreliable, the planting site is almost certainly the culprit.
For homeowners, the practical lesson is that a Thuja planted in a generously sized bed with good soil, adequate irrigation, and some distance from pavement will grow far faster and look far better than one wedged into a narrow strip between a sidewalk and a foundation wall. Giving the roots room to spread and access moisture is the single best thing you can do for growth rate, more effective than any fertilizer regime.
Container Growing and Nursery Starts
Many Thuja are purchased as container-grown nursery stock, and the conditions during that nursery phase can affect how quickly the tree takes off after planting. Research on ‘Green Giant’ arborvitae found that the growing substrate and container type significantly influenced plant size and biomass. Plants grown in a pine bark and peat moss blend were larger and had greater shoot and root mass than those grown in pine bark alone, likely because the peat-amended mix held more water.7Horticulturae. Container Type and Substrate Affect Root Zone Temperature and Growth of ‘Green Giant’ Arborvitae White-colored containers paired with the peat-amended mix produced the best results, apparently by keeping root-zone temperatures lower in summer.
This matters for shoppers because not all nursery stock is created equal. Two ‘Green Giant’ arborvitae of the same listed size can perform very differently in their first year depending on how well developed the root system is. A plant that comes out of its pot with dense, white roots throughout the soil ball will establish faster than one with circling roots confined to the bottom. When you are choosing Thuja at a garden center, tip the pot and look at the root mass. A healthy, well-grown nursery plant should have roots that fill the container without being tightly wound.
Deer Browsing and Other Setbacks
Thuja occidentalis is famously attractive to white-tailed deer, and browsing pressure is one of the most common reasons that young arborvitae fail to grow as expected. A study in northeastern forests found that browsing becomes the dominant factor limiting cedar seedling development once the plants reach about 50 centimeters in height. Below that threshold, factors like canopy shade and competition from existing cedar basal area matter more, but above it, deer damage takes over as the primary growth limiter.8Forests. Escape Game: Responses of Northern White Cedar (Thuja occidentalis L.) to an Extreme Reduction in White-Tailed Deer (Odocoileus virginianus Zimmerman) Population Even after a dramatic reduction in the local deer population, the study found that a two-year period was not enough for the cedar regeneration structure to visibly recover.
For gardeners, this means deer protection is not optional in areas with significant browse pressure. A young arborvitae that gets its leader repeatedly nipped will grow slowly and develop an irregular shape. Individual tree cages, deer netting, or repellent sprays applied consistently through winter are the standard defenses. Some gardeners choose ‘Green Giant’ partly because its faster growth helps it push past the most vulnerable height window more quickly, and its foliage may be slightly less palatable than T. occidentalis, though deer will still eat it if hungry enough.
Beyond deer, bagworms are the other major pest that can devastate Thuja growth. These caterpillars construct spindle-shaped cases from foliage fragments and can defoliate large sections of a tree in a single season. Heavy infestations stunt growth severely and can kill branches or entire plants. Hand-picking the bags in late fall and winter, before caterpillars emerge in spring, is the simplest control method for small hedges. For larger plantings, targeted insecticide applications in early summer when the larvae are small and actively feeding tend to be most effective.
Choosing the Right Thuja for Your Timeline
Growth rate is usually the first filter people apply when picking a Thuja, and matching the variety to your patience level and available space saves years of frustration. If you need a privacy screen quickly and have room for a large tree, ‘Green Giant’ is hard to beat. It fills in a row to functional screening height within about four to five years from typical nursery size, then continues to grow into a substantial tree that can reach 40 to 60 feet at maturity. The trade-off is that you need to plan for that eventual size. Planting ‘Green Giant’ three feet from a property line will create problems in a decade.
If you want something more manageable, ‘Emerald Green’ (Thuja occidentalis ‘Smaragd’) is the default choice for narrower hedges. Its growth rate of roughly 6 to 12 inches per year means it takes longer to fill in, but its naturally compact, columnar shape requires little to no pruning to maintain a tidy appearance. For anyone on a tight lot or working near a fence line, that slower pace is actually an advantage because the tree never gets much wider than about three to four feet.
Dwarf and miniature cultivars like ‘Hetz Midget,’ ‘Danica,’ or ‘Little Giant’ grow only a few inches per year and top out well under five feet. These are not hedge material. They are accent plants for borders, rock gardens, and containers. Trying to grow a privacy screen from dwarf arborvitae would be an exercise in decades-long patience.
One common mistake is planting a fast-growing variety too close together, expecting to trim it later. Thuja that are crowded from the start compete for light and water, and the interior foliage dies out permanently. Unlike deciduous shrubs, arborvitae do not regenerate green growth on old wood. If you shear a hedge back into bare brown stems, those sections stay bare. Spacing plants according to their mature width rather than their nursery width is the only way to avoid thin, hollow hedges down the line.
Winter Burn and Seasonal Growth Patterns
Thuja growth is seasonal. In most temperate climates, the bulk of annual height increase happens in a flush from late spring through early summer, with a smaller secondary flush in some years. By midsummer, most terminal buds have set and vertical growth is essentially done for the year, though the plant continues to add girth and root mass into fall.
Winter burn is a common cosmetic setback that can make it look like your Thuja has stopped growing or is dying. The brown, desiccated foliage that appears on the south or southwest side of arborvitae in late winter is caused by a combination of bright sun, cold wind, and frozen soil. The foliage loses moisture to transpiration on sunny winter days, but the frozen roots cannot replace it, so the needles dry out and turn brown. In most cases the damage is superficial and the tree pushes new green growth in spring, but severe or repeated winter burn weakens the plant and slows the following season’s growth.
Wrapping young arborvitae in burlap or anti-desiccant spray can help in harsh-winter regions, especially during the first two or three winters after planting. Once a Thuja is well established and its root system has reached deeper, more insulated soil layers, winter burn becomes less of an issue. Siting the hedge where it gets some shelter from prevailing winter winds also makes a noticeable difference, and watering thoroughly in late fall before the ground freezes gives the roots a moisture reserve to draw on during winter thaws.