Interested in Growing Avocados? Check Your Soil First

In the past few years, an increasing number of homeowners have been bitten by the fruit-tree bug. Instead of roses or marigolds, people are interested in growing their own citrus, pear, apple or avocado trees.

But whether you want to start producing tree fruits with an eye toward profit, or you are simply interested in stocking your kitchen with fresh fruit that you grew yourself, it makes sense to select a species and variety that warrants a high price tag. You’ll either pocket more cash while selling your crops at the local farmer’s market or save more money at the grocery store, but you’ll help your bottom line in either case.

And if you are interested in producing a high-priced tree fruit, it is hard to find a better example than the avocado. Avocados are relatively expensive fruit in the first place, but because of climate change and other socioeconomic factors, it is likely to increase drastically over the next several decades. In fact, future harvests are expected to fall by about 40 percent, which will cause the price of avocados to skyrocket.

But you must be sure that you are equipped to care for avocado trees before you start shopping for your stock. You’ll obviously need access to a reliable (and affordable) water supply and plenty of sun exposure, but one of the most critical aspects of avocado production relates to the soil you have available.

Make sure that you address the following soil characteristics before setting out to install your new trees:

  • Soil Structure: Avocados are shallow-rooted trees, whose roots are incapable of penetrating into compacted soils, so it is always best to break up the soil in the planting hole before introducing the tree. They prefer very coarse, well-drained, loamy soils, and they will struggle to thrive in heavy clay soils. Additionally, it is imperative that avocados not be planted too deeply, as this can stress the root systems and damage the trunk. Avocado trees cannot tolerate soggy soil, particularly while the temperatures are low, so it is better to err on the shallow side when you are planting these trees. Many California-based avocado farmers grow their trees on raised mounds, to help ensure adequate drainage and prevent root rot.


  • pH: Avocados grow best in slightly acidic soils, with a pH of between 5 and 7. Alkaline conditions limit the ability of avocado trees to absorb iron and zinc, which will ultimately lead to their demise. You can use elemental Sulphur to help reduce the pH of the soil when necessary, but you must be sure to plan ahead and address these issues before planting your avocados, as it can take six months or longer to properly adjust the pH.


  • Salt: Avocado trees are very sensitive to salt. Salt spray from the ocean, salt in the local water supply and salt in the soil are all problematic, so it is important to consider the salt content of these things and your geographic location before deciding to grow avocados.


  • Fertilization: Avocado trees respond best to small, frequent applications of fertilizer, rather than infrequent and heavy applications. Nitrogen and potassium (particularly after the trees begin to produce fruit) are the most important nutrients to supply to young avocados, while supplemental phosphorus rarely appears necessary. By the time they are about 10 years old, most avocado trees have produced a thick layer of mulch, comprised of their shed leaves. This usually eliminates the need for supplemental nitrogen.

Tree Growth Explained: The Magic of Meristems

From a macro view, trees appear to grow in many different ways through the course of a season. Their leaves unfurl and enlarge in the spring and their fruit swell in the summer.

But this is not true growth – after all, the tree will shed these structures eventually.

True growth occurs when trees produce new wood. This kind of growth produces tissue that persists from one season to the next.

But even this growth is a very location-specific phenomenon, and it only occurs in a few places throughout the tree.

These places are called meristems.

Apical Meristems

Apical meristems occur at the tips of branches and roots. They are responsible for a tree’s longitudinal growth along its axis, or, put more plainly, they are the place from which branches and roots grow longer. Arborists and botanists consider growth from the apical meristem to be primary growth.

However, apical meristems also produce the cells that will become the plant’s secondary growth center – the lateral meristems.

Lateral Meristems

Lateral meristems are found in the thin ring of tissue around the circumference of a tree’s trunk, branches and roots. These lateral meristem regions (which exist along the entire length of the branch or root in question) are responsible for increases in girth, rather than length.

Lateral meristems occur in two different tissues of each branch. The innermost ring is called the vascular cambium, while the outer meristem layer is called the cork cambium. Each produces new tissues from both the inner and outer surface of the ring.

More specifically, the cork cambium produces cork cells on its outer surface and phelloderm cells on its inner surface. The cork cells will eventually die and become the outer bark, while the phellogen is a parenchyma-rich layer of cells that serves to store starch for future use.

Further inside the tree, the vascular cambium produces phloem tissue on its outer surface and xylem cells (wood) on the inner surface. Phloem tissue transports starches along the length of the branches, while xylem transports water from the roots to the leaves and supplies support and stability to the tree as a whole.

The Arboricultural Implications of Meristems

With the understanding that trees only grow from these regions, it is important to apply this knowledge to the ways in which we prune trees. There are a number of ways to use this knowledge, but the following include some of the most important:

  • Because it removes a large number of a tree’s apical meristems, topping is a destructive practice that should be avoided. Removing a branch’s meristem often results in the branch’s death, and it forces the tree to grow from lateral branches, rather than the branch tip.


  • Tree branches do not move higher off the ground with time. Because trees grow from the tips of their branches, and not from the trunk’s base, limbs do not move higher with time. This means that an obstructing limb will remain in the way unless you remove it. Arborists must perform a procedure called a crown raising to deal with these types of limbs.


  • Narrowly spaced, co-dominant stems force material to grow inside the wood of the junction. When a tree produces a pair of trunks, the expansion in girth causes the tree to produce wood around the bark material, sandwiched between the two. This makes such junctions weak, as the bark does not attach well to the wood inside the junction.



aralia_elata_en_fleur4081-1Aralia is a genus of nearly 70 different species that exhibit a diverse array of growth habits. Some reach tree-like proportions, while others are nothing more than shrubs. Some of the large varieties grow as multi-stemmed plants, slightly reminiscent of both bamboo and tropical palms. Many members of the genus bear impressive spines, which lead to common names like spikenard, Hercules’ club and Devil’s walking stick.

Distinctive Leaf Arrangement

Despite their varied characteristics, all species in the genus Araliahave very distinctive, bi-pinnately compound leaves. This means that instead of having leaves that connect directly to the twigs via a small stem (simple leaves), or having leaflets which combine to form a single leaf (compound), Aralia plants have stems that emerge from the twig, and split into a collection of sub-stems, each of which bear several leaflets. At a glance, the leaf appears to contain two ranks of twigs.

Growth and Culture

Aralia species grow naturally in several parts of the United States, so they can often be seen in forests and other natural habitats. However, they are also grown ornamentally as specimens, hedges or borders. In fact, some people have begun growing Aralia species indoors. This is possible in part because many Aralia are understory species that grow well in low light levels, and remain small enough to work in interior applications.

Notable Species

Despite the number common traits found across all species in the genus, Aralia species still exhibit considerable diversity. Some of the most noteworthy species include:

  • Devil’s walking stick (Aralia spinosa) – The Devil’s walking stick is native to the southeastern United States, from upstate New York across to eastern Texas. It prefers well-drained soils and does best in U.S.D.A. Hardiness Zones 4 through 9. Devil’s walking stick is an understory species, that thrives best in partial- to full-sun. Some people eat the tender young leaves of this plant, and Native Americans often incorporated the seeds into their diet.
  • American spikenard (Aralia racemose) –Native to the eastern United States, the American spikenard is an ornamental species, prized for its attractive foliage and dark red fruit. Like many other Aralia species, the American spikenard thrives in shady habitats.
  • California spikenard (Aralia californica) –Unlike some of its eastern relatives, which range through a dozen or more states, the California spikenard is only native to California and parts of Oregon. Although it never becomes woody, this attractive shrub may approach 10 feet in height. Known locally as elk clover, California spikenard features long, divided leaves. A popular ornamental plant, the California spikenard thrives in U.S.D.A. Hardiness Zones 3 through 8.
  • Japanese spikenard (Aralia cordata) – Because it grows as an herbaceous perennial, and its new shoots are eaten by many of those who live alongside it, the Japanese spikenard is also known as mountain asparagus.Reaching about 6 feet in height, Japanese spikenard is a fast-growing plant that thrives best in acidic soils. It commonly grows on wooded hillsides in Eastern Asia.
  • Japanese angelica tree (Aralia elata) –Like those of the Japanese spikenard, the young shoots of the Japanese angelica tree are also widely consumed by humans. This species grows in a tree-like form, occasionally reaching 30 feet or more in height. Like the Devil’s walking stick, the Japanese angelica tree produces sharp bark prickles which help to protect the trees from predators.

Yellow Oleander (Thevetia peruvianasyn. Cascabela thevetia)

Yellow OleanderHailing from Mexico and Central America, the yellow oleander (Thevetia peruviana) is a large shrub or small tree adorned with beautiful yellow to peach flowers, that are very popular among gardeners and homeowners.


The classification and composition of the genus Thevetia is cloaked in controversy. Some authorities consider the genus to be a part of the genus Cascabela, while others maintain that, while the two groups are closely related, they remain distinct. In either case, there are between three and eight species recognized, with the yellow oleander (Thevetiaperuviana syn. Cascabelathevetia) being the most commonly encountered form.


All parts of the yellow oleander are poisonous – even the milky sap. Ingestion typically leads to cardiac symptoms and electrolyte imbalances, which may be fatal without medical attention. Humans aren’t the only species susceptible to the poisons, as dogs, cats and horses may also suffer ill effects after eating the plant. Nevertheless, a few birds– including Indian gray hornbills (Ocyceros birostris) and several bulbul species (Pycnonotus spp.) — feed upon the plant’s fruit without apparent problem.

The plant’s toxins were so widely respected among Central Americans that the tree was often called the cascabel (a Spanish word often applied to rattlesnakes), which is a reference to its ability to kill as readily as a rattlesnake can.

Growth and Culture

Yellow oleanders are heat-loving trees who prefer warm temperatures and ample sunlight. Plant them in exposed, sunny locations whenever possible, but they will usually survive in areas of partial shade.They are best suited for U.S.D.A. Hardiness Zones 9 and 10, although they are also grown in Zone 8, although precautions must be taken to protect the plants from unusually cold temperatures.

Despite their tropical native range, yellow oleanders grow well in Mediterranean climates – such as those found along much of California’s coastline. While their growing location must be well-drained, they typically adapt well to most soils. While they are generally considered a reasonably drought-tolerant species, your plants will appreciate supplemental water during dry spells.

In general, yellow oleanders are low-maintenance plants, that cause their caretakers little trouble. They are often pruned while small to encourage them to develop a tree-like growth habit, but thereafter, the pruning needs of these small trees are relatively minor. The tallest specimens may reach 20 feet, but most will remain under 10 feet tall. They do produce hard, black to red seed capsules, which present an annual litter problem, but they are otherwise unimposing.

Invasive Species

Thanks to its popularity, yellow oleander is cultivated and grown in suitable climates around the world, including India, Sri Lanka and other portions of South Asia. In many of these places, the plants have escaped cultivation and spread throughout natural habitats, where it has become an invasive species. Although the plant has some wildlife value, it also outcompetes a number of native species, to the detriment of the habitat and greater ecosystem.

Some of the locations in which yellow oleander has become naturalized include Australia, Tanzania, Uganda and portions of East Africa. It has also established itself on many Pacific Islands and some parts of the U.S. One important side effect of this species’ range expansion is the danger it represents to domestic or agricultural animals who may feed upon the plant’s flowers or seeds.


OleanderNamed after their superficial resemblance to olive trees, Oleander (Nerium oleander) is an attractive shrub or small tree that thrives in a Mediterranean climate. Originally hailing from North Africa and West Asia, property owners can now purchase oleanders in any of more than 400 different forms.

Size and Shape

Oleanders most commonly grow as large, bushy shrubs, but some specimens develop a tree-like size and shape. Most oleanders are only a few feet tall, but the largest examples may reach 20 feet in height. When large, oleanders tend to exhibit an umbrella-like growth habit. Their stems grow in a relatively narrow clump, but the tops of the branches spread out and cascade toward the ground.

Flowers and Foliage

Oleander leaves are dark green and arranged in pairs (although they occasionally feature a whorled leaf arrangement). An evergreen plant, oleander remains quite attractive throughout the year.

Nevertheless, people do not typically fall in love with oleanders because of their dark green leaves – the flowers are the oleanders’ claim to fame. Sweet-scented and abundant, oleander flowers are as beautiful as they are plentiful; they often bloom throughout the entirety of the warm season. Most oleanders have white or pink flowers, but some cultivars yield flowers ranging from yellow to red.

Unlike many other flowers that depend on the help of insects for pollination, oleanders do not appear to provide any benefit to the insects that visit them. Instead, they appear to use deceptive practices to trick bees into visiting the flowers, even though they produce no nectar on which the bees can feed.

The downy seeds are released from long, thin pods; they take to the air and drift far away when strong winds blow.

Terrible Toxins

While they do not appear to be toxic to many rodents or birds, oleanders are toxic to humans and some other animals. The toxins produced by the plant may cause gastrointestinal upset, heart rhythm problems and even nervous system disturbances – in some cases consumption has resulted in death. However, many tales of oleander poisoning are little more than myths. While you should certainly avoid consuming any part of the plant (all tissues potentially bear the toxic components), human deaths from consuming the plant are relatively rare.

Some people report that contact with the sap of oleanders can cause a skin rash, so caution is advised when contacting the plants. Many insects that feed upon the leaves sequester the ingested toxins and use them as a defense mechanism. Because they are toxic, oleander trees and shrubs typically receive little damage from deer and rabbits.

Geography for Growing

Oleanders grow best in USDA Hardiness zones 8 through 10, but many people have successfully grown them outside of this range. Tough plants, oleanders can handle a wide array of challenges, including high temperatures, periodic drought, periodic flooding, compacted soils, salt spray and high pH levels. However, they are very sensitive to temperatures below about 20 degrees Fahrenheit. When exposed to such chilly temperatures, they almost always suffer damage.

However, if protected from low temperatures, oleanders can thrive just about anywhere. Many people grow them as indoor, potted plants and move them outside during the summer. Alternatively, they can be grown inside the climate-controlled confines of a greenhouse.

Custard Apples

Custard Apples

Custard Apples

The term custard apple tree is applied in two different ways: Some use it to describe all members of the genus Annona, while others only apply the name to the species Annona reticulata. Fortunately, while the genus Annona is quite large (with approximately 150 to 175 species, depending on the authority consulted), the species all share a variety of similar traits.

Most custard apple tree species are native to Central America and Africa, although several species have been domesticated and are grown in suitable climates the world over. The fruit of several species has significant commercial value, particularly in the developing world.

Size and Shape

Custard apples are medium-sized trees that usually reach heights of between 15 and 40 feet. They aren’t considered especially attractive trees, so they are typically grown for food production rather than as ornamentals. Additionally, custard apple trees have very soft wood that breaks easily – particularly when the branches are weighed down with a full fruit crop. Most commercial custard apple farms utilize wind breaks to help protect their trees and maximize their crop.

Nevertheless, custard apple trees can be planted ornamentally, although they only thrive in U.S. Hardiness Zones 7 through 9. Skillful pruning can improve their appearance and help keep them looking their best. Despite the fact that they aren’t ideal shade trees, they do offer most of the same benefits that similarly sized trees do (such as providing shade and wildlife habitat as well as reducing local temperatures).

Their deciduous leaves are about 5 to 8 inches long and rather narrow. They are typically dark green on their top surface and lighter green beneath.

Fruits and Flowers

The flowers of custard apple trees are somewhat bizarre-looking. In fact, they never open completely the way most other flowers do. They bear three extraordinarily long outer petals and three smaller inner petals (the inner petals are very difficult to see). This flower construction belies their close relationship with paw paws (Asimina spp.). Large horned beetles appear to be the primary pollinators of most Annona species.

The resulting fruit is somewhat large and equally strange. Varying in shape from oblong to spherical (and occasionally heart-shaped), the ripe fruit varies between yellow and red in color. The taste is described as being custard-like, which is the reason for their common name.

Growing Tips

Custard apples grow best in very well drained soils. Although they do produce a significant taproot extending vertically below the trunk, the bulk of the absorbing roots reside in the upper layers of the soil. However, these trees are very susceptible to root rots and bacterial wilt. In fact, The Queensland Department of Agriculture and Fisheries recommends that growers refrain from planting custard apple trees in soils that formerly harbored tomatoes, potatoes, eggplant and several other common crops, due to the likelihood that bacterial spores may already lurk in the soil. However, root-zone issues aside, custard apples do not often succumb to many pests and diseases that afflict other fruiting trees.

Custard apple trees require warm temperatures to thrive, and they grow best in areas with long, humid summers and mild, dry winters. Established custard apple trees can survive moderate droughts, but without ample rainfall and relative humidity levels of 70 percent or more, custard apple trees may shed their leaves and produce a minimal crop.

Toxic Properties

Several components within custard apple trees are potentially bioactive, and several primitive cultures use different parts of the plants for medicinal purposes. Some of the plants in this genus produce toxic seeds, which can cause a degenerative neurological condition in humans. Strangely, this only seems to occur on the island of Guadeloupe.

The leaves of custard apple trees also bear several bioactive compounds. They not only possess insecticidal chemicals; their tannins are used to make dyes.


Japanese Umbrella Pines

Japanese Umbrella Pines

The Japanese umbrella pine (Sciadopitys verticillata) is the single described member of its genus, and – as its name suggests – it is a Japanese endemic. While a popular ornamental that is grown in many locations around the world, they are considered sacred in their native range.


Japanese umbrella pines are unusual-looking trees that rarely solicit lukewarm opinions – as explained by the University of Florida Extension Service, “people either love this tree or won’t even look at it.” The whorled tufts of evergreen needles found at the end of the trees’ branches are said to resemble umbrellas, hence the species’ common name.

Interestingly, these umbrella-like needles carry out photosynthesis, but are not “true leaves.” Instead, the trees’ true leaves occur as scaly, twig-hugging structures. The foliage of these trees is often quite dense.

Although the cones are not produced for some time, those that eventually appear are relatively attractive. They are about 3 or 4 inches long and become quite plump at maturity.

The bark of Japanese umbrella trees is very attractive, having a rich-reddish-brown coloration. Its texture is often described as “fibrous” or “stringy.” Upon cutting into the wood, one immediately becomes aware of the wood’s distinctive, spicy fragrance.

Growth and Longevity

Japanese umbrella pines grow very slowly and take several decades to mature. Growing to about 90 feet in height in their native lands, most umbrella pines remain much smaller – typically less than 35 feet tall – when planted elsewhere.

The largest and likely oldest living specimen is located near a temple in the town of Nodagawa. The temple’s records indicate that the tree has been growing at the site for the last 700 years.

Evolutionary History

Although a member of the same order that contains living pines and spruces, the Japanese umbrella pine has no close relatives in the modern world. Japanese umbrella pines were originally classified within the family Cupressaaceae, but they have recently been moved to their own family, the Sciadoptiyaceae. This unusual conifer is a relic from an ancient time; researchers have collected fossil remains of these trees that are approximately 230 million years old. In fact, the species represents one of the oldest living conifer taxa in the world.

Extinct relatives of the species probably grew across vast expanses of North America, Europe and mainland Asia. Additionally, the trees probably played a more important ecological role in the Mesozoic Era than they do in the modern world.

Culture and Commercial Uses

Japanese umbrella trees are shade tolerant, but they grow best in partial to full sun. They grow best in USDA Hardiness Zones 4 and 5, although some authorities list them as hardy from Zones 3 through 7. Several cultivars of the species are available commercially, including a weeping form and a dwarf form, which only reaches about 10 feet in height.

While these trees require well-drained soil and have relatively modest water requirements, they are most common in humid cloud forests within their native range. These hardy trees are also resistant to most pests and pathogens, making them relatively low-maintenance trees. While these trees are most common among gardeners and landscapers, some bonsai practitioners utilize these attractive conifers.

The wood of Japanese umbrella pines is water-resistant; so many boat makers use it in ship construction.


China-firs (Cunninghamia ssp.) are impressive trees, attaining heights of 150 feet in their native lands. Although they are native to Asia, they have been planted in the Unites States since the beginning of the 19th century. Fortunately, they do not exhibit invasive habits, so you can plant them in your yard without feeling guilty.

Taxonomic Topics

Despite their common name, China-firs are not true firs; the lineage is actually more closely related to the redwoods. Botanists disagree whether the genus contains one or two species. While most recognize two species, some evidence suggests that both populations form a single species. Cunninghamia lanceolata occur on mainland China, Vietnam and Laos, while Cunninghamia konishii are indigenous to Taiwan, although some scientists recognize cloud-mountain populations from Vietnam and Laos as members of konishii.

Growth and Characteristics

Despite their tendency to grow into towering specimens in the wild, most China-firs planted outside of their native range grow to between 50 and 75 feet tall. China-firs sometimes produce multiple stems, although the majority exhibit very tall, columnar growth habits. The bark of mature specimens forms long strips that peel from the tree, providing interesting aesthetics for any landscape. Fortunately, the crown of these trees is usually rather open, allowing you to see the handsome bark. Dead leaves tend to persist on the tree for several years, until the entire branch is dropped. Some consider this a drawback for the species, while others find it to be part of the plant’s considerable charm.

Commercial Applications

China-fir wood has a number of valuable properties, including a pleasant aroma and extreme resistance to decay. It is an important commercial species in China, as it is frequently used in the construction of temples, coffins and other items for which a pleasant aroma is desirable. The primary limitation for commercial propagation is the minimum winter temperatures of a particular region, which may cause the tree stress during the late winter.

Awesome Ornamentals

Because it resists most insects and diseases, adapts well to a variety of soil conditions and can tolerate moderate shade, China-firs are great ornamental specimens. The primary limiting factor for their use is the space available. They are best planted as specimen trees on large properties. Nevertheless, the trees grow best in moist, well-drained soils. Avoid exposed sites that are difficult to keep from drying out, as the plants require significant soil moisture during establishment. However, once they have become established, they are very drought resistant – an important quality for our drought-stricken area. Deer reportedly find the needles unpalatable, and the slightly prickly leaves will help to keep mischievous children at bay. Because China-firs often tolerate urban conditions well, they are also used as street trees.

Notable Cultivars

Several China-fir cultivars are available, allowing landowners to select a form well suited for the space available. The ‘Glauca’ cultivar usually stays much smaller than some other forms, topping out at about 50 feet in height. The cultivar is also noteworthy for its pale blue needles, which may offer a unique color for landscapes. The ‘Samurai’ cultivar may remain even smaller, although its growth rate is quite rapid.


Tasmanian Cedars (Athrotaxis spp.)

Tasmanian cedars are attractive conifers, native to the temperate rainforests of west Tasmania. Even though these trees originate on the opposite side of the planet and inhabit very different ecosystems, they resemble a few North American natives.

The Family Tree

Although Athrotaxis species often bear common names including terms like “pine” or “cedar,” they are neither; instead, Athrotaxis are in the cypress family (Cupressaaceae). Accordingly, Tasmanian cedars are closely aligned with other members of the cypress family, such as Atlantic white cedars (Chamaecyparis thyoides), bald cypresses (Taxodium distichum) and arborvitaes (Thuja occidentalis).

Species Specifics

Taxonomists disagree on the number of species present within the genus; some evidence suggests the genus contains two species and a hybrid of the two, while other evidence is consistent with the existence of three distinct species.

Besides growth form and habitat preference, the three species are very similar in general biology. They all exhibit roughly similar life cycles and reproductive strategies. All Tasmanian cedars are monoecious trees, meaning that individual trees bear both male and female cones. About six months after pollination, the quarter-inch-long cones open and release scads of tiny seeds.

Pencil Pines (Athrotaxis cupressoides)

Pencil pines are medium-sized trees, averaging about 20 to 30 feet in height. However, occasional specimens exceed these heights, climbing up to 60 feet above the ground. Pencil pines have scaly leaves, which lie against the tree’s branches. Pencil pines often occur at the top of the timberline, at higher elevations than Eucalyptus trees grow. This helps to explain why pencil pines are the most cold tolerant of the Tasmanian cedars; but curiously, all three forms exhibit similar drought- and flood-tolerance, despite preferring different elevations.

King Billy Pines (Athrotaxis selaginoides)

King Billy pines are the largest of the three forms, occasionally reaching heights of 90 feet. The leaves are much different from those of the pencil pines; they are elongate, pointed and claw-like. Formerly an important timber species, the wood of King Billy pines is soft, lightweight and rot resistant. Unfortunately, the useful wood is unsuitable for commercial harvest, given its slow growth rate and bush-fire-induced decline.

Summit Cedars (Athrotaxis laxifolia)

Summit cedars share some similarities with pencil pines and others with King Billy pines, and they appear like a cross between the two species. A number of clues suggest that summit cedars are the naturally occurring hybrid offspring of pencil and King Billy pines. For example, the cones and leaves of summit cedars are intermediate between those of the other species. Additionally summit cedars only grow in habitats that contain both other species.


None of the three species is common outside its native range, although all three thrive in many botanical gardens of northwestern Europe, where the mild climate and ample rain suit the trees well. Athrotaxis prefer cool summers, mild winters and abundant rainfall, and they are rated for USDA Hardiness Zones 7b – 10b. While not commonly grown in the United States or seen in nurseries, Tasmanian cedars may thrive in cool Californian microclimates. Seeds are occasionally available from commercial sources; summit cedars are more commonly seen than the other two species.

Lifespan and Growth Rate

All three species of Athrotaxis live long lives. Several living pencil pines are more than 1,000 years old, and scientists know of at least on living specimen — a King Billy pine – that is nearly 800 years old. All species are relatively slow growing; for example, a King Billy pine planted at the Osborne House – a seaside palace on the Isle of Wight – is over 100 years old, yet has only grown to a height of 25 feet.