Alcock's spruce (Picea alcoquiana 'Howell's Tigertail')

Overview

Picea alcoquiana ‘Howell’s Tigertail’, commonly known as Alcock’s spruce, is a fantastic evergreen offering compact structure and beautiful bicolor needles. This cultivar is specifically valued for its spreading, often flat-topped growth habit, which allows it to fit into smaller landscape niches where its taller relatives would overwhelm the space. It retains the distinctive foliage characteristics of the species, featuring needles that are deep green on top and suffused with silver-blue underneath, adding visual texture.

This durable conifer provides excellent year-round structure and requires relatively low maintenance once established, making it a favorite for busy gardeners. While the standard Alcock’s spruce can reach towering heights, the ‘Howell’s Tigertail’ form remains manageable, typically topping out around 4 to 6 feet tall initially, though selective pruning of the leader can keep it smaller. The reddish-purple emerging cones add a seasonal splash of color before ripening.

For gardeners seeking reliable texture and form in a needle evergreen that handles varying conditions well, Picea alcoquiana ‘Howell’s Tigertail’ is an excellent choice. Its compact nature makes it incredibly versatile for foundation plantings or rock gardens, providing permanent color and screening capability without aggressive vertical growth.

Fast Facts

• Plant Family: Pinaceae
• Plant Type: Needled evergreen
• Hardiness Zones: USDA Zones 3-7
• Size at Maturity:
  • Height: 4-6 ft
  • Spread: 2-5 ft
• Bloom Time: Non-flowering
• Bloom Description: Non-flowering
• Sun Exposure: Full sun
• Water Needs: Medium
• Maintenance Level: Low

How to Grow

Planting the Picea alcoquiana ‘Howell’s Tigertail’ is best done in the spring or fall when temperatures are moderate, allowing the root system to establish before summer heat or winter cold hits. Ensure you select a location that receives full sun, as adequate light is necessary for maintaining dense coloration and compact form. This spruce thrives in average, medium moisture, well-drained soil and surprisingly tolerates some light shade and clay soils, offering flexibility in siting.

Consistent moisture is crucial during the establishment period; water deeply whenever the top inch of soil begins to feel dry. Once mature, Alcock’s spruce requires medium watering, though established plants are generally resilient. Avoid overly exposed sites where harsh prevailing winds can dry out the foliage, causing scorch, a common issue for many conifers.

Maintenance for Picea alcoquiana ‘Howell’s Tigertail’ is generally low. Significant fertilization is rarely necessary unless the plant is in poor soil. If pruning is desired—perhaps to manage the natural tendency to develop a central leader into a specific shape—prune lightly in early spring before new growth begins. Remember this conifer is notably intolerant of most air pollutants, making it a better choice for suburban or rural gardens than dense urban areas.

Landscape Uses

The manageable size and unique horizontal spread of Picea alcoquiana ‘Howell’s Tigertail’ make it an outstanding anchor in various landscape designs. It excels when placed near the edge of borders or integrated into mixed rock gardens where its texture can contrast nicely with deciduous shrubs or broadleaf evergreens. The dense foliage also lends itself well to use as an informal screen or foundation plant, softening the harsh lines of structures.

Consider using this Alcock’s spruce as a specimen plant where its bicolor needles can be appreciated up close, especially near walkways or patios. In broader designs, it serves as an excellent low-growing evergreen accent, requiring minimal upkeep for maximum impact throughout the year. Its low profile, especially if the leader is managed, avoids the shadow effects associated with taller trees near structures or smaller companion plants.

Standout Features

Noteworthy Characteristics

Picea alcoquiana (synonymous with Picea bicolor) is an evergreen conifer that is native to a limited but stable number of subalpine forest areas in the mountains of central Japan. The specific cultivar ‘Howell’s Tigertail’ is a spreading flat-topped form that will eventually develop a central leader unless this leader is pruned out. If the leader is retained, plants may grow in an irregular pyramidal form to 4-6’ tall over the first 10 years and eventually mature to 20’ tall or more, featuring bicolor needles that are green on top and silver-blue beneath.

Tolerances

• Deer

Potential Problems

Picea alcoquiana ‘Howell’s Tigertail’ generally boasts a clean bill of health, with no known serious, pervasive insect or disease issues when sited correctly. Gardeners should remain vigilant, however, as conifers are susceptible to common pests under stress. The most commonly reported irritants include spider mites, aphids, budworm, bagworm, borers, and pine needle scale.

Management usually involves proactive cultural care, such as ensuring proper watering to reduce drought stress, which makes the plant vulnerable to mites. If an infestation occurs, dormant oil sprays in winter or insecticidal soap applied during the growing season can control soft-bodied pests like aphids and mites. Regular inspection will help catch problems like borers early, ensuring your Alcock’s spruce remains healthy.

Frequently Asked Questions

What hardiness zones is Alcock’s spruce suitable for?

Picea alcoquiana ‘Howell’s Tigertail’ is reliably hardy in USDA Zones 3 through 7.

How large does Picea alcoquiana ‘Howell’s Tigertail’ grow?

It is relatively compact, reaching heights between 4 and 6 feet, with a spread of 2 to 5 feet, especially when young or when the central leader is pruned.

What sun exposure does Alcock’s spruce need?

This needled evergreen prefers a location receiving full sun for the best growth and color saturation.

When does Picea alcoquiana ‘Howell’s Tigertail’ bloom?

As a conifer, this specimen is non-flowering, meaning it does not produce traditional flowers, although it does produce attractive reddish-purple cones.

Conclusion

The Picea alcoquiana ‘Howell’s Tigertail’ offers exceptional value with its low-maintenance profile and unique spreading habit, perfectly complementing rock gardens and foundation plantings. Its distinctive bicolor needles ensure visual interest year-round, making this Alcock’s spruce a sturdy, dependable evergreen. Before planting, confirm your local conditions fall within its hardy range of Zones 3-7 and ensure the site offers well-drained soil and full sun exposure.

Companion Planting

When selecting partners for Picea alcoquiana ‘Howell’s Tigertail’, prioritize plants that share similar needs for sun exposure and medium moisture. Its low, spreading habit pairs beautifully with taller, fine-textured grasses or upright, smaller deciduous shrubs that offer seasonal color contrast. Consider pairing it with low-mounding Japanese maples (if shade tolerant), which offer contrasting leaf texture, or groundcovers like Sedum or dwarf Hosta varieties if placed in light shade.

Avoid planting aggressively spreading or deep-rooted perennials directly adjacent to the spruce, as they may compete significantly for surface moisture and nutrients. The consistent, silvery-blue tones beneath the needles provide a cool base note, allowing brighter colored perennials, such as coral bells (Heuchera) or dwarf ornamental grasses, to visually pop when planted nearby.

Design Ideas: Foundation and Edging

Given its mature height potential of only 4 to 6 feet, Picea alcoquiana ‘Howell’s Tigertail’ shines as a foundational element where taller conifers would obscure architecture. Plant it slightly away from the foundation wall, allowing its flat-topped habit to unfurl naturally. It works exceptionally well near entrances or corners where a low, permanent hedge effect is desired without significant mass.

For a modern, minimalist design, group three or five specimens of this low-growing Alcock’s spruce together in a tight cluster against a light-colored wall. This arrangement emphasizes the structural form and the contrast between the sunlit tops and the silver undersides of the needles (the “telltale” aspect of its name). Its slow growth rate means these groupings require minimal reshaping over many years.