How to Grow and Care for a Scots Pine Tree

The Scots pine (often known incorrectly as Scotch pine) is Scotland's national tree. This long-needled pine is a famously popular specimen for Christmas trees, but its long life (up to 300 years) also makes it a popular specimen in landscaping.

The central trunk of the Scots pine is long and straight, with scaly, flaking bark that is dark near the bottom, turning a rusty color toward the top. The needles are 1 to 4 inches long, depending on variety, shedding about every three years. The needles are bunched in pairs that twist together. The seed-bearing cones are pinkish-red when young, maturing to gray-brown; they are 1 to 3 inches long and feature diamond-shaped scales.

The tree is pyramidal in shape when young, but becomes flatter on top as it ages. This tree is best planted in spring or autumn. It grows at a moderate rate, about 1 to 2 feet per year. It can easily grow 125 feet or more in height, with a trunk 3 feet or more in diameter. Most mature specimens reach about 60 feet tall, with a width of about 40 feet. This tree is an invasive species in some parts of the U.S.

Scots Pine Tree Care

This large tree is sometimes planted as a specimen in large landscapes and public parks, but it is more often used to form windbreaks or screens on farms or in large rural landscapes. It is not the best tree for ordinary residential landscapes due to its large size, but it is sometimes planted where soils are very difficult. It is also very commonly grown commercially for the Christmas tree market. Scots pine is not grown for its lumber.

Light

Plant it in a location where it gets at least 6 hours of full sun each day, and make sure to give it plenty of space, as this is a tree that will get very large.

Soil

The Scots pine will tolerate almost any type of poor soil, which makes it valuable in land reclamation projects. Scots pine has a good tolerance for clay soils and drought but needs well-draining soil.

Water

Young trees need about 1 inch of water per week. Mature trees only need water during hotter days and only if the tree has not received rainfall recently.

Temperature and Humidity

Scots pine is native to northern Europe and Central Asia. It can thrive in many climates, though it does not do well in subtropical or tropical regions.

Fertilizer

Fertilizer is not necessary, but if you do feed it, only give it fertilizer once a year in the spring just before it comes out of dormancy, using a 15-5-10 slow-release fertilizer. Spread the fertilizer in a band just under the outer perimeter of the pine's canopy, raking it into the top layer of the soil. Water the tree thoroughly immediately after feeding. Mulch the area around the base of the tree to a depth of 3 to 4 inches, and reapply mulch every 1 to 2 years. Once established, this tree requires little care.

Types of Scots Pine

Scots pine is suitable for growing in USDA hardiness zones 2 to 9, depending on the variety. Several naturally occurring varieties include:

• P. sylvestris var. sylvestris: Found across most of the naturally occurring range, from Scotland and Spain to central Siberia. This tree is used in landscape applications and the Christmas tree market.
• P. sylvestris var. hamata: This variety is native to the Balkans, northern Turkey, Crimea, and the Caucasus.
• P. sylvestris var. mongolica: This tree occurs naturally in Mongolia, parts of southern Siberia, and northwestern China.
• PInus sylvestric or Waterer Scotch pine: This modest-sized cultivar grows to 20 feet with a spread of 12 feet. It is a relatively slow-growing variety and is used as an accent specimen more than other, larger varieties.
  

Pruning

Pruning is usually unnecessary unless you want to maintain the classic Christmas tree shape. To promote thicker growth, pinch off the new growth shoots ("candles") in the spring as they appear. Remove dead branches, and if branches rub together, prune one of the branches away.

Propagating Scots Pine

Scots pine is grown from planting seeds or stem cuttings. Stem or branch cuttings are a good way to grow new plants from pruned branches or new growth. Here's how to propagate Scots pine from stem cutting:

1. You will need a pot with ample holes, moistened potting soil, pruners, plastic wrap, and rooting hormone.
2. Take 4- to 6-inch cuttings from healthy branches with new growth. Dip the cut end in the rooting hormone.
3. Pull off the pine needles from the cut-end side, leaving only the top half of the pine needles intact on the stem.
4. Plant the cut-end in moistened soil, such as peat or perlite mixed with sand in a pot with ample holes for good drainage.
5. Cover the pot with plastic to keep the humidity up, also place the cutting in a warm, brightly lit spot.
6. Remove the plastic for about one hour each day to allow the cutting some fresh air. Remove the plastic completely once new growth appears. It may take up to one year for cuttings to take root. New growth is proof the cutting is establishing new roots. Replant the cutting in the ground or a new pot after it has developed several more inches of growth.
   

How to Grow Scots Pine From Seed

For germination success, consider stratifying (tricking seeds they've gone through winter) or putting them in potting soil in a container in the refrigerator for at least four weeks.

Next, sow the seeds indoors by placing them in individual pots with well-drained potting soil. Push each seed just beneath the soil surface with the pointy end of the seed facing downward.

Place the pots in a sunny window and water thoroughly, always keeping the seeds moist (but not too soggy). Germination may take about three to four months.

Potting and Repotting Scots Pine

Plant newly rooted or young seedlings in the ground in the spring. If repotting new saplings, only repot every two or three years in the late fall or early spring. Do not repot too much, since repeated transplanting can shock and potentially kill the plant. Cut back on the water before repotting, keeping the soil slightly dry.

To transplant, remove the root ball from the pot, keeping it whole. Prune away old roots from the bottom and sides. Remove some old soil from the middle of the soil ball and replace it with new soil in the new pot. Cover the root ball with new soil. Do not make it too big of a pot, since a deep pot may get soggy soil, which can lead to root rot.

Overwintering

Mature Scots pines can handle winter without a problem. Seedlings and saplings are more sensitive to cold winters and will need some protection. Use a layer of mulch to insulate the soil around the seedling about 4 to 6 inches thick. Also, water the young tree thoroughly at least twice a month throughout fall and winter.

Protect the young tree trunk from winter winds and foraging animals with chicken wire and a burlap wrap until its root system is well established. The tree will need several years to establish a strong root system.

Common Pests and Diseases

When a Scots pine develops yellowing needles along a single branch, this may be a sign of a pine wilt fungal disease, called Cyclaneusma needle cast. Consult an expert for confirmation. The tree will need to be removed and destroyed since it is incurable. Western gall rust and Lophodermium needle cast are also common in some areas.

Several insects are known to affect Scots pine, sucking pine sap, which can kill or severely affect these trees, including:

• Pine spittlebug (Aphrophora parallela)
• European pine sawfly (Neodiprion sertifer)
• Pine root collar weevil (Hylobius radicis)
• Giant conifer aphid (Cinara spp.)
• Pine needle scale (Chionaspis pinifoliae)
• White pine weevil (Pissodes strobi)
• Pine root tip weevil (Hylobius rhizophagus)
• Zimmerman pine moth (Dioryctria zimmermani)

To treat these pests, try an insecticidal soap first. Also, horticultural oil applied in early spring is another good solution. Only move on to chemical pesticides if these organic solutions prove unsuccessful.

Porcupines and birds, especially pine grosbeak, can also cause damage to the tree.

Common Problems With Scots Pine

Scots pine trees are tough trees that can handle many climates and soils. They like full sun and can withstand a frigid winter. The rule of thumb to keep these plants thriving is to protect them in their early years.

Yellowing Pine Needles

This condition can be caused by the soil being too wet and poor drainage. Soggy soil leads to root rot and needle yellowing. Another potential cause is needle scorch when the soil is too dry on hot days. Insufficient light, ventilation, or pines shocked by too much sunlight can also cause yellowing needles. Also, in fall, when deciduous trees lose their leaves, Scots pines may also experience seasonal yellowing and needle drop; usually, they'll drop their old needles every three years.

Evaluate the conditions of your Scots pine to determine what's affecting your tree. Adjust the watering schedule accordingly. If your tree is not getting enough light or is too crowded by other trees, you might want to consider replanting it in a better location.

Tree Appears to Be Dying

If the plant's bark is wrinkling, peel back a bit of the branch bark. If the inner layer of the bark is dry and brown, it's dead. If it's still green underneath it still has life. If the tree is low on water, give it water, but do not overdo it; it can shock the tree.

If pine needle yellowing only occurs on the old needles, the tree can bounce back. If yellowing occurs on old and new growth, the tree may be more difficult to revive. Remove the lower branches of a pine tree that are dead, dying, or damaged to reinvigorate the tree.

Swollen, Soft Trunk, and Red Needles

If a tree's bark starts to appear swollen or soft, it can be a sign of Cronartium ribicola or rust. If you notice a lot of yellowish-whitish sores on the lower part of the trunk, and the tree develops red needles, it likely has this fungal infection. If it appears on branches, remove the branches. Cut down and destroy diseased branches. Infected parts that are cut out, should be layered with pine tar as a salve for the cuts.

Oozing Sap

A little bit of sap is no reason to worry. However, if the sap is steadily streaming from the tree, it is likely injured from physical breakage, insects, or disease. Cankers are fungal growths that spread under the bark and affect the tree, sometimes causing sap to ooze. These growths can kill a tree if not handled early on. Chemicals can't control cankers, but if you prune it out early, it can eliminate the problem from spreading.