the larch (larch) the genus includes about 14 individual and hybrid species of deciduous conifers that shed their needles in winter and grow back in spring. Within this group, there are three species, each with numerous named cultivars, that are commonly planted as landscape trees in North America. Larch trees have a sparse and somewhat patchy growth habit that reduces their popularity, but their excellent cold hardiness and autumn color are notable virtues.
Larch trees are known for their autumnal displays of golden-yellow needles that make them not only particularly attractive, but also more hardy than other conifers. The tree is bare during the winter and therefore the needles cannot be damaged in extreme cold. The needles of larches, which grow in dense clusters, are soft, not sharp or prickly like other conifers. Larch trees vary in the shape and size of their needles and branches, some being pyramidal in shape, while other cultivars have a weeping growth habit.
Larch trees are usually planted as potted nursery plants or bare-root specimens in autumn or early spring; these trees transplant well during dormancy. Larch trees are fairly fast growing trees, adding 12 to 18 inches per year, and are extremely long-lived in the right conditions.
|botanical name||Larix spp.|
|plant type||dry leaf tree|
|mature size||40 to 100 feet tall, 20 to 30 feet wide|
|kind of solo||Moist but well-draining|
|pH do solo||Acid to neutral (5.0 to 7.4)|
|flower color||Pink for green cones|
|robustness zones||2-7 (USDA); depends on the species|
|Native Area||North hemisphere|
The care needs of larches vary somewhat depending on the species. tamara (L. laracina), for example, prefers decidedly moist soils, while the other types prefer moist but well-drained soils. All larches prefer locations in full sun. The size of larches varies greatly; so if you want to plant one, be sure to choose a species or cultivar whose mature size is appropriate for your garden.
The planting technique is typical for woody plants: prepare a planting hole the same depth as the container or clod and twice as wide. Plant the specimen so that the top of the root ball is level with the soil, then backfill, tamp the soil and water well.
Once established, larches are undemanding but do not do well in regions with high air pollution. Depending on the species, the tree may require light annual pruning to control its shape and size.
Most larch species require full sun, but some can toleratepartial shade. Consult the specific cultural needs of the species you are growing.
Generally speaking, larches prefer medium-moisture, well-draining soils, but larch (American larch,L. laracina) likes a decidedly soggy environment. In its natural habitat, this species often grows in swamps where the soil contains little or no oxygen: the soil pores are filled with water instead of air. Any moist, peat-rich soil that mimics this environment is a good site.
Larch trees do not grow well in soils withpH alto— Look for acidic to neutral soil (pH 5.0 to 7.4).
Larch trees need a lot of moisture and do not tolerate drought. Some types even work well in places with temporary flooding. Especially in the first two years after planting until the tree is established, make sure the soil is constantly moist and never dries out.
temperature and humidity
Larch trees are hardy trees that adapt well to climates with cool summers and cold winters. They do not tolerate hot weather, especially when combined with high humidity.
Newly planted larches should not be fertilized during the first or second growing season. When a larch is planted in healthy soil rich inorganic matter, fertilizer is never needed. If a soil test reveals a lack of phosphorus and potassium, apply acomplete fertilizerfor established trees each spring.
types of larício
Popular larch species and varieties grown in North American landscapes include:
- deciduous larch(European larch or common larch)it has an adult size of 100 feet tall and 20 to 30 feet wide. There are two popular minor cultivars: weeping larch,deciduous larch'Pendula', which grows only 10 to 12 feet tall, and the gnarled European larch,deciduous larch'Horstmann's Recurved' with twisted and curved branches. It is slow growing to a height of just 4 1/2 to 7 1/2 feet and a width of just 3 to 4 feet at maturity.
- Larício KaempferI (Japanese larch)it has an adult size of 70 to 90 feet tall and 25 to 40 feet wide. Smaller cultivars are also available here: weeping larch,Alerce kaempferi'Pendula', the twisted cultivar 'Diana' and 'Blue Dwarf' with bluish foliage.
- larch(eastern larch, American larch oralerce tamarack) It reaches 40 to 80 feet tall and 30 to 50 feet wide at maturity. The tree is native to most of northern North America. A smaller cultivar is the globe-shaped one.larch'Blue Sparkler', which reaches just 12 feet tall and 3 feet wide. It is a less popular landscape tree than the European and Japanese species, due to its insistence on moist soil.
Other larches that are less commonly planted as landscape trees include:
- Larix lyallii(subalpine larch, alpine larch or lyall larch)it can grow up to 80 feet. It is native to northwest North America and is an important tree for native wildlife. Birds such as the blue grouse, as well as mammals such as the ibex, feed on its needles.
- siberian larch(Siberian larch or Russian larch)It reaches 80 to 200 feet at maturity. It is native to western Russia and Siberia.
- western laris(western larch)it can grow up to 150 feet tall. It is native to the mountains of the northwestern United States and has a high wildlife value, serving as a host for nest-building animals.
- Alere born(larício dahuriano)reaches 40 to 90 feet tall and 15 to 30 feet wide at maturity. It is native to northeastern Siberia, Mongolia and northeastern China. There are four varieties originating from different areas and with different needles; one of them is the japanese varietyAlere bornera.japanese rosebush
Pruning is not a requirement for larches, but dead or damaged branches should be pruned as you notice them. If additional pruning is needed to control shape or size, do it during the winter or early spring, before new growth begins.
Propagation of larch by vegetative means is generally not done outside of the nursery trade, as many named cultivars are grafted specimens, in which the branches are fused with the rootstocks of the species. Therefore, softwood cuttings are quite difficult to root. Most often, larches are propagated by seeds.
How to grow larch from seeds
Larch trees are usually propagated from seed, although this is a time-consuming process that few hobbyists are willing to attempt.
Seeds harvested from mature cones harvested in the fall must first be cold stratified, storing them in a cool place for a full year, then an additional three months at 40 degrees Fahrenheit during the second winter. In spring, sow fully stratified seeds in small pots filled with peat-based potting mix, topped only with 1/8 inch or additional potting mix. Place the pots in a cool, dark place out of direct sunlight and keep the mixture moist until the seeds sprout, usually about a month. Move the containers to a brighter location, but without too much direct sunlight, and continue growing them until fall, when they can be planted in the landscape.
Larch for pots and transplants
Larch trees are fast-growing trees that are rarely planted in containers, with one exception: when used in bonsai practice. Both the European larch (deciduous larch) and Japanese larch (Alerce kaempferi)They are used by amateur bonsai. Larch trees have short, fine needles that provide excellent texture at a scale appropriate for a bonsai.
Bonsai larches are grown in shallow pots filled with common potting mix. Plants will need to be watered lightly every day during the growing season, less frequently during the dormant season. Daily pinching is a normal task for any bonsai practice, with main branch pruning taking place in early spring. These plants are easily wire-trained. The transplant should be every one or two years.
Larch trees grown as bonsai need cool, dry air to keep the needles small. These plants are deciduous and are usually grown outdoors or at least moved to a cool location during the winter dormancy period when they lose their needles.
spend the winter
Larch trees thrive in cool climates and generally don't need protection from the cold. However, young trees can be susceptible to wind damage and may benefit from tents or burlap shields in the first year or two. Young seedlings may be susceptible to being fed by deer and rabbits, so chicken coop screen protectors are sometimes used.
Common plant pests and diseases
The most common disease of larches is larch needle, also called Meria's needle. It is a fungus that is triggered by damp conditions in spring. It starts with brown spots on the needles and gradually moves towards their base. Brown needles fall off prematurely. The best line of defense is to make sure the tree is from a nursery where the disease is not present. This disease can kill a tree, but it can sometimes be cured with fungicide applications starting just after bud break in the spring. Repeat applications will be needed every two to three weeks until the weather dries out. Chlorothalonil and propiconazole are the recommended fungicides.
Larch trees are also prone to a serious canker disease which is first identified when droplets of resin appear in swollen lesions on the bark. Affected branches should be pruned and then destroyed or burned.
The damage caused by larch, a European moth, begins with tiny caterpillars that invade the needles. Later, the larvae feed on needles. The tips of the needles may appear burned or, if the infestation is severe, the tree may be completely leafless. Fortunately, larch populations are generally controlled by cool, wet spring weather and late frosts, as well as natural predators such as birds and parasitoid wasps that have been introduced for biological control of the pest. Chemical treatments include application of fungicides early in the season, followed by control of larvae with pesticides.
How to make larch bloom
The flowers (cones) of larches are not particularly showy and there is no particular reason to encourage flowering, except to harvest the cones for seed. In any case, there are rarely problems with cone production, although the tree must reach a level of maturity before cone production begins. This can take anywhere from eight to 25 years, depending on the species and variety you are growing.
Common problems with larch
The tree is ugly, sparse in winter
Intrigued by the beautiful yellow needles in autumn, some homeowners who don't research this tree are surprised when a larch takes on the appearance of a large, barren branch in winter after the needles drop. Keep in mind that larches are deciduous and do not provide the winter color that other conifers are known for.
The needle tips are burned
Larch trees are very sensitive to air pollution such as ozone, and high levels of these pollutants can cause the tips of their needles to turn a reddish-brown color. Tree growth can also be severely stunted. Larch trees are best planted in rural areas with good air quality, although Japanese larch resists the effects of urban pollution somewhat better.
frequently asked questions
How long does a larch live?
Longevity varies somewhat from species to species, but in general, larches are very long-lived trees, with 250-year-old specimens being common.
What is the best larch species for landscaping?
Most horticulturists suggest that European larch (deciduous larch) perform better in the landscape than native North American larches. But Japanese larch (Alerce kaempferi) has better resistance to higher levels of pollution in urban areas.
Why do larches turn yellow in the fall?
As with broadleaf deciduous trees, deciduous conifers such as larch respond to cooler temperatures by moving chemicals that drive photosynthesis to other areas of the tree. This causes a color change in the foliage.
Do larches pose a fire hazard?
Larch trees are less dangerous than other resinous trees, mainly because dropping their needles in winter reduces the amount of dry bait. If you live in this region, larches are a better choice than many other conifers.
Spruce only uses high-quality sources, including peer-reviewed studies, to support the facts in our articles. read ourpublishing processto learn more about how we fact-check and keep our content accurate, reliable, and reliable.
Oregon State University College of Agricultural Sciences.deciduous larch
you, Miguel.woody landscape plant manual, Stipes Publishing, 1998
- Cornell University Woody Plant Database.larch
you, Miguel.Handbook of Landscape Woody Plants, 5th Edition.Stipes Publication, 1998
Wisconsin Division of Horticultural Extension.Larch European Larch Decidua
Japanese Larch Bonsai,Chinese bonsai garden.
Meria needle mold.Extension of the University of Massachusetts.
Sikora, Edward and Chappelka, Arthur. Damage caused by air pollution to plants.Alabama Cooperative Extension Service