The dwarf Alberta spruce is an evergreen conifer with a classic pyramidal Christmas tree shape that rarely exceeds 13 feet. This spruce tree variety is related to trees that grow 100 feet or taller. The most popular landscape idea for a dwarf Alberta spruce is for foundation plantings, used as a large shrub or small specimen tree all over America. This dwarf version grows very slowly—about 2 to 4 inches per year. The aromatic green needles are about 1/2 inch long.
The tree has a tight, densely-packed growth habit that gives dwarf Alberta spruce trees a "fuzzy" look. Unlike its larger white spruce cousins, the dwarf Alberta spruce rarely produces pine cones. Plant seeds in late spring or early fall. After a cold period and the temperature begins to warm, it triggers germination and new growth. It is commonly kept in containers as a young shrub and adorned with Christmas tree ornaments and holiday ribbons during the winter months. Read on to see how to care for a dwarf Alberta spruce.
|Common Names||Dwarf Alberta spruce, dwarf white spruce|
|Botanical Name||Picea glauca 'Conica'|
|Mature Size||10 to 13 ft. tall, 7 to 10 ft. wide|
|Soil Type||Moist, well-drained soil|
|Soil pH||Acidic, neutral, alkaline|
|Hardiness Zones||3 to 6 (USDA)|
|Native Area||North America|
Dwarf Alberta Spruce Care
The dwarf Alberta spruce is best suited for a climate with cold winters and cool summers. The dwarf Alberta spruce tree grows in USDA hardiness zones 3 to 6, but it is temperamental in the warmer zones 6 through 8. A dwarf Alberta spruce grows best in full sun and well-drained acidic soil. It will tolerate some light shade but performs best in a spot with good air circulation; its dense foliage can trap moisture.
If the soil is less than ideal, amend it by working compost or another organic material into the top 15 inches of soil before planting. The planting hole should be twice as wide as the tree's container and about 2 inches deeper. Water thoroughly after planting and cover the ground around the tree with a thick layer of shredded bark mulch. Keep the mulch at least 3 inches away from the trunk. For the first year, water the tree weekly, saturating the soil to a depth of at least 3 inches.
These plants can eventually outgrow a small space. Avoid planting this tree in a spot that cannot comfortably accommodate a 10- to 13-foot tree.
The dwarf Alberta spruce needs full sun to perform at its best but it will tolerate some shade. Give these plants an eastern or northern exposure. Avoid planting where harsh winter winds or hot afternoon sun can burn them.
Grow dwarf Alberta spruce in moist, well-drained soil. It does best in soil that is slightly acid to alkaline in pH. These plants work well with regular potting soil with added peat moss. Cover with shredded bark mulch.
Water dwarf Alberta spruce when the top 3 inches of soil is dry. If you keep this plant in containers, water it more often than you would water in-ground plants. These plants do not like soggy soil, so beware of overwatering.
Temperature and Humidity
Dwarf Alberta spruce performs best in areas with cold winters and cool summers. This plant does best in low-humidity environments. This mini tree requires good air circulation.
Young plants respond well to mixing in a granular fertilizer around the tree's base once a year. For an organic alternative, try a natural fertilizer like fish emulsion. Mature trees require no feeding.
Types of Dwarf Alberta Spruce
Larger forms of white spruce can grow up to 100 feet tall. The dwarf varieties can be used as container plants or specimen planting. Spruce trees are popular for providing year-round color in your landscape.
- Picea glauca 'Jean's Dilly': This shorter form of Alberta Spruce (up to 5 feet tall) has needles that are concentrated at the ends of each season's short stem growth and a distinctive twist to the needles.
- Picea glauca 'Rainbow's End': This type grows up to 10 feet tall with a second flush of growth in the midseason with yellowish-green to creamy yellow-colored foliage.
- Picea glauca 'Tiny Tower': Featuring an excellent pyramidal form with a dwarf habit that is perfect for smaller gardens, its dense, bright green foliage turns an attractive gray-green and is well-suited as a formal topiary.
Pruning is not necessary with dwarf Alberta spruce since it grows so slowly. Damaged branches should be removed whenever you find them. Pruning can be done in late winter or early spring when new growth appears. Cut no more than 2 to 3 inches off the tips of the branches. You can keep a dwarf Alberta spruce small by trimming it into a topiary form when grown in a container.
Propagating Dwarf Alberta Spruce
The two ways to grow dwarf Alberta spruce are from seeds or branch cutting. The quickest way to propagate this plant is by using a 6-inch-long softwood branch cutting taken in late summer or early fall. Softwood branches are long and firm branches but should not be hardened and woody. Here's more about the cutting method:
- Gather sterilized pruners, potting soil mixed with peat moss and sand, a 3-inch pot, and a brightly lit location for the cutting to grow.
- Strip the needles from the lower two-thirds of the branch. Dip the cut end into the rooting hormone to promote rooting, then plant it deeply into the soil.
- Keep the soil moist until roots form. As a slow-growing plant, root formation can take up to 6 to 8 weeks. You'll know the plant is rooting when you notice some new plant growth. Once you notice new growth, transplant it into a larger pot or a landscape location.
How to Grow Dwarf Alberta Spruce From Seed
If you have access to a dwarf Alberta spruce tree, harvest seeds mid-fall. Spruce seeds grow in cones. Pick them young before they ripen. Extract the seeds from the cones by allowing the cones to dry out, open, and spill out the seeds. This can take up to two weeks.
Some people like to scar or weaken the outer coating of the seed to promote germination. These seeds also need temperatures to cool and warm up to make the seed believe the winter season (and dormancy) is ending and the growing season is about to begin.
If you are starting your seed indoors, plant the seeds about 1/4-inch deep in a pot with moistened potting soil amended with peat moss and sand, wrapped in a plastic bag in the back of a refrigerator for about three to four months. Gradually warm up the seeds by moving the pot to a cool garage or basement or taking it outside, periodically hardening off over four weeks as spring approaches, and giving the plant at least 6 to 8 hours of light.
Alternatively, you can also leave the newly potted seed outdoors (sheltered in a non-windy area) during the winter months. The seed will enter dormancy and naturally acclimate to the warming temperatures when spring returns.
Potting and Repotting Dwarf Alberta Spruce
This tree is often grown in a container to use as a living Christmas tree. It can be moved outdoors in the early spring but needs to be hardened off by gradually exposing it to outdoor conditions.
A pot helps bind the root system. A pot-bound dwarf Alberta Spruce will grow slower and shorter than plants that have more room to grow. When repotting (usually every two to four years), make sure there is a 6-inch diameter available from the root ball so that it can be well-established. Use well-draining potting soil with ample drainage holes. These plants do not like overly wet soil.
If you keep this plant in containers outdoors, you will need to protect your dwarf Alberta spruce in the winter so it can survive. The biggest concern is the harsh wind chill that could permeate the potting container. To protect the plant's potted roots, plant the pot in a yard or move the plant to an area sheltered from windy conditions. You can further insulate the roots by surrounding the containers with bales of hay or straw.
Common Pests and Plant Diseases
Dwarf Alberta spruce trees are not very tolerant of air pollution and salt spray, and they struggle in areas with high heat and humidity. They require very little care but are often the victims of spider mite attacks that can kill the tree. A yearly preventative treatment with a pesticide may prevent this. An organic alternative to a synthetic pesticide is weekly treatment with insecticidal soap.
Common Problems With Dwarf Alberta Spruce
You must live in zone 3 to 8 to grow this tree outdoors; zones 3 to 6 are the most ideal. It doesn't prosper well in climates that have really hot, humid summers. But, if you live in a cooler area like the northern U.S. or Canada, then this plant is much easier to grow. The biggest problem with a dwarf Alberta spruce is its need for plenty of air circulation to keep pests like pesky spider mites away. Do not crowd this plant to keep it happy.
Needles Turning Brown and Dropping
The dwarf Alberta spruce's needles will turn brown and drop if it gets crowded. If this happens, trim off the brown leaves. New growth may reemerge. Excessive heat, winter burn from harsh winds or too much sun exposure, and too much water, or not enough water may also cause yellowing and browning. Adjust those conditions, if possible.
Crowded conditions will also encourage a spider mite infestation. To check for mites, get a piece of white paper and shake the branches over the paper. If you notice insect activity, it is likely a mite infestation, and, they can appear as red, green, or black oval specks. Make sure the plant is not crowded, wash away spider mite webs and insects, and start treatment with an insecticidal soap weekly.
Browning Reaching the Trunk
Winter burn can occur during sunny winter days when the needles dry out since the branches and roots have very little access to water. The browning will appear lopsided, mainly at the south or west part of the plant—where the sun is usually strongest. To prevent winter burn, water the plant fully in the fall before the ground freezes so the roots can soak up the moisture before the ground freezes. Cover the ground at the tree base with 2 to 4 inches of mulch to reduce moisture loss. If the entire tree turns brown, the plant is a lost cause. Replace it and start again with a regular watering regimen or a different sun exposure.
Browning at the Top of the Plant
If the top of the dwarf Alberta spruce begins turning brown, it is likely a problem with the trunk or the roots. Closely inspect the trunk to see if animals are chewing the base of the plant. If the bark is gone from the plant, the tree will have to be replaced. If the plant is getting too much water, its roots can be rotting or drying out, killing the tree and requiring replacement. If you catch the problem soon enough and the plant is still small, you can dig up the root ball and inspect it. If you notice blackening, mushy roots, it has root rot. If you notice it still has healthy roots, you can try to save it. Cut away the diseased section of rotted roots with a sharp, sanitized knife. Treat it with an antifungal according to the directions. Repot it in fresh, well-draining soil in a sterilized pot.
Are dwarf Alberta spruce easy to care for?
If you live in the right zone, these plants are usually a cinch to cultivate and grow. The main things to look out for are spider mites and planting them with the correct sun exposure. Also, if you use salt to control the snow and ice around your house, make sure that your plant is not near the salt spray. Salt can harm your plant.
What is the dwarf Alberta spruce's lifespan?
Spruce trees, including this dwarf variety, are slow-growing, long-lived trees. It grows on average about 2 to 4 inches per year. It can take about 30 years to reach its maximum size of 10 to 13 feet based on that rate. And, if in an ideal location, it can live on for many years. A white spruce's average lifespan is over 200 years.
Can dwarf Alberta spruce grow indoors?
Yes, this tree can grow indoors; however, a dwarf Alberta spruce can reach up to 13 feet tall, so the plant will likely outgrow your space. These plants do not like too much humidity, and they prefer cooler temperatures. If you are caring for a dwarf Alberta spruce indoors, make sure to water these plants thoroughly. In the winter, when the sun exposure is less and the plant is not in its growing season, reduce watering significantly.
Picea glauca 'Conica' - Dwarf Alberta Spruce (Pinaceae). Ohio State University.
Spruce spider mite. Missouri Botanical Garden.
Why is My Spruce Tree Turning Brown? City of Aberdeen, Parks, Recreation & Forestry Dept.