Larch trees (Larix spp.), also known as tamaracks, are needle-bearing conifers with an unusual trait: unlike pines, spruces, firs, and other coniferous relatives, larches are deciduous. They are adapted to cold, northerly and mountainous regions, where they are valued for their soft foliage, uniform growth habit, and brilliant golden foliage in the fall.
A Brief Look at Larches
Several species of larch are grown for landscaping purposes, but they are all quite similar in appearance and growing requirements -- overall size is the main difference among them. Larch is hardy in USDA zones 2 to 6.
Larches have very soft needles -- another trait that separates them from other conifers -- that grow from one to four inches long depending on the species. The cones mature in fall and range from 1/2-inch to two inches in size.
Like most conifers, larches need full sun, but they are one of the few that prefer to grow in wet soil. The soil must also be acidic and rich in organic matter, mimicking the boggy locations where these trees are found in the wild.
Planting and Caring for Larches
Plant larches from established nursery grown trees, which are widely available in the regions where they are suitable for growing. They are useful as single specimens in rock garden environments, Asian-themed landscapes, and woodland gardens. They are also useful as a tall hedgerow.
Dig a hole to the depth of the root ball and two or three times as wide. Gently loosen the roots before placing the tree in the hole. Mix compost into the soil as it goes back into the hole and spread a thick layer of mulch over the planting area. Pine or fir needles or shredded bark makes a suitable mulch.
Larches need little care other than ensuring the soil remains constantly moist. The top of the tree should never be pruned, but the lower limbs can be removed as the tree grows up to let light in below and expose the trunk.
Pests and Disease
The trees are prone to a number of pests and diseases ranging from aphids to fungal rusts to caterpillars to sawflies. It is generally impractical for homeowners to treat larch pests directly, due to the size of the tree and difficulty of determining the culprit. The best approach is prevention -- only plant larches if you truly have the right conditions. However, professional arborists can be called upon for help if a larch tree appears to be under attack.
The standard larch tree has a uniform pyramidal shape, but several varieties are available with more unusual growth habits.
- 'Pendula' is a weeping variety that grows to 25 feet.
- 'Varied Directions' is a bizarre weeping variety growing 15 feet tall and 20 to 30 feet wide with branches that arch every which way.
- 'Blue Sparkler' is a dwarf variety with bluish needles that grows to just 12 feet in height.
For the Love of Larches
Because of their unusual nature larches are treasured horticultural specimens. They have a soft, spritely appearance during the growing season capped off with an explosion of fall foliage that rivals any deciduous tree.