How to Grow and Care for Ponderosa Pine

The ponderosa pine (Pinus ponderosa) is one of the most common pines in North America. It is often used in large landscapes because of its stature and ability to add some dazzling green color for winter interest in areas that get frequent snowfall. Growing at its best in the mountainous country west of the Mississippi River, the ponderosa pine reaches colossal heights in the wild. However, it will top off at a still intimidating height of 60 feet or so when grown in cultivation. The tree grows 12 to 18 inches per year and its mature size keeps all but those with huge properties from considering adding the tree to their landscape. Luckily, numerous cultivars are available in different forms and sizes that even fit into smaller landscapes.

Ponderosa pine is planted during its dormant season in the fall or spring.

Ponderosa Pine Care

Here are the main care requirements for growing a ponderosa pine:

• Plant it in full sun and well-draining soil.
• Water the young tree regularly, daily at first, then weekly, for at least one, or better, for two growing seasons.
• Only fertilize young trees. Mature trees do not need fertilizer unless the soil has a specific nutrient deficiency.
• Prune during dormant season.

Light

This tree needs full sun to thrive; it does not tolerate shade.

Soil

The ideal soil for ponderosa pine is a mix of gravel, sand, and loam with a pH between 6.0 and 7.0 and good drainage. However, as long as the soil has a slightly acidic to neutral pH and it's not soaking wet, ponderosa pine will grow. This species is rather forgiving in terms of soil conditions, more than other pines.

Water

An established ponderosa pine has great drought tolerance but a young tree needs extra watering. Ponderosa pines are notorious for their root ball drying out, which happens in just one day depending on weather conditions. Always check the actual water needs before watering and water the tree lightly but frequently. A tree with a caliper of less than 2 inches needs to be watered daily for the first two weeks, 1 to 2 gallons per inch of trunk diameter. After the first week and during the first two months, give the tree 2 to 4 gallons per inch of trunk diameter every other day. After that, water the tree weekly until it is fully established, which may take two growing seasons or more.

Temperature and Humidity

Ponderosa pine is a very cold-hardy evergreen tree that performs best in cool, dry conditions and does poorly in humid climates. The areas where the tree grows naturally in USDA Zones 3 to 7 are often mountainous and just because you are in the hardiness range of the tree does not mean that the climate conditions in your area are suitable.

Fertilizer

There is no need to fertilize an established ponderosa tree unless the soil is lacking a specific nutrient, a fact that only a detailed soil test can reveal. To boost the overall health of a young tree, amend the soil beyond the dripline of the tree with compost and widen the area that you water accordingly. Alternatively, feed the young tree a slow-release evergreen-specific fertilizer in midspring in the first two years.

Types of Ponderosa Pine

There are two recognized varieties of the ponderosa pine, Pinus ponderosavar.ponderosa(Pacific ponderosa pine) and Ponderosa pine var.scopulorum(Rocky Mountain ponderosa pine). Most suitable for most home gardens, however, are the dwarf varieties that come in different forms, sizes, and growth rates. These include:

• P. ponderosa'Pondy': A dwarf ponderosa pine with a globose form with needles that are a bit smaller than those of the species. It will grow to about five feet after ten years of growth.
• P. ponderosa'The Sphinx':A pyramidal, dwarf selection of ponderosa pine with tight, uniform branching and long needles. It is slow-growing, reaching a size of 3 feet in height and width after ten years. USDA Zone 5-8
• P. ponderosa'Warm Valley': This dwarf variety originated as a witch’s broom. It has a globose growth habit and grows very slowly, only 1 to 3 inches per year, to a size of 4 feet tall to 3.5 feet wide.

Pruning

The main reason to prune a ponderosa pine is to remove dead or broken branches or growth that is getting too close to a structure or a passageway. Pruning should be done in late winter or early spring while the tree is dormant. Cut the branch all the way back to the branch collar (the spot where the branch is attached to the trunk or a larger branch) and never remove more than 25 percent of the tree in any given year.

Propagating Ponderosa Pine

Ponderosa pine is difficult to propagate from cuttings; it is usually propagated from seed. However, obtaining suitable seeds is difficult for home gardeners, as the most viable seeds come from trees that are 60 to 160 years old. The seeds from cultivars (the types that most home gardeners will likely choose due to the smaller tree size) won’t produce plants that are true to the parent. The long time that it takes to grow a ponderosa pine is another reason why propagating your own ponderosa pine is not recommended.

Potting and Repotting Ponderosa Pine

Despite their small size and slow growth rate, even a dwarf ponderosa pine is not a good choice for container growing. The tree has a deep tap root and a widespread root system that will be too confined in a pot.

Overwintering

Ponderosa tree is well-equipped to withstand subzero winters and does not require any winter protection.

Common Pests & Plant Diseases

Ponderosa pine can be affected by many different insect pests, not all of them serious. Infestations with pine beetles, Western pine beetles, and bark beetles cause tree death. The tree is also prone to parasites, especially dwarf mistletoe, root diseases, rusts, trunk decays, and needle and twig blights.

From: thespruce