Caring for a Nannyberry (Viburnum lentago)

Caring for a Nannyberry (Viburnum lentago) in Lethbridge, Alberta, requires attention to the plant’s preferences and the unique climate of the area. Nannyberry is a hardy native shrub, often used in landscaping for its attractive berries and fall color. This guide is based on firsthand experience from the Nikka Yuko Japanese Garden in Lethbridge, Alberta—a city located in hardiness zone 4B, where winters are cold, and the climate is relatively dry. You can also see Nannyberry by visiting Nikka Yuko.

Planting Location

• Full Sun to Partial Shade: Nannyberry prefers full sun but can tolerate partial shade. Aim to plant it in a location that receives at least 6 hours of direct sunlight daily, though it can tolerate some afternoon shade.
• Well-Drained Soil: Nannyberry prefers moist, well-draining soil, but it is fairly adaptable and can tolerate a variety of soil types. If your soil is heavy or clayey, improve drainage by adding organic matter like compost or sand. The soil pH should be slightly acidic to neutral (around 6.0 to 7.0).
• Wind Protection: While the Nannyberry is relatively hardy, Lethbridge experiences strong winds. Planting it near a windbreak (such as a fence or building) can help protect it from harsh winds, especially during winter months.

Soil and Fertilization

In the right conditions, you can expect your Nannyberry to grow one (1) to two (2) feet per year.

Quick Growing Guide

Botanical Name: Viburnum lentago

Botanical Family: Adoxaceae

Colour:

• Maroon
• Orange
• White

Blooms:

• Spring

Sun / Shade:

• Full Sun

Water: Water if and when the soil dries.

Soil:

• Neutral acidity
• Slightly Acidic
• Well drained

Height:

• Up to 9+ feet (over 3 meters)

Width:

• Up to 8 feet (240cms)

Hardiness Zones:

• 2
• 3
• 4
• 5
• 6
• 7

Care:

• Easy to Care and Grow

Propagation Method

• From Seed

• Soil pH: Nannyberry thrives in slightly acidic to neutral soil (pH 5.5 to 7.0). If your soil is too alkaline, consider adding elemental sulfur to lower the pH.
• Fertilization: Fertilizing is generally not necessary unless the plant shows signs of nutrient deficiency. If you choose to fertilize, use a balanced fertilizer (10-10-10) in early spring before new growth begins. Avoid excessive fertilizing, as this can encourage weak, leggy growth.

Watering

• Moisture Requirements: Nannyberry prefers moist conditions, especially during the growing season. While it is somewhat drought-tolerant once established, it still needs regular watering, especially in dry periods. Deeply water the shrub about once a week during dry spells.
• Watering Tips: Water deeply to encourage deep root growth. Be careful not to overwater or let the plant sit in waterlogged soil, as this can lead to root rot. Ensure the soil drains well, especially in areas with heavy clay soil.
• Mulching: Apply 2-3 inches of mulch around the base of the plant to help retain moisture, regulate soil temperature, and suppress weeds. Mulch also helps protect the roots during winter.

Pruning

• Timing: Prune Nannyberry in late winter or early spring while it is still dormant. Avoid pruning in the fall as this can remove buds that will produce flowers and berries.
• Pruning Tips: Remove dead, damaged, or diseased branches. You can also shape the shrub to encourage a more compact, dense form. Light pruning will help maintain a healthy, attractive shape.
• Deadheading: While it’s not necessary to deadhead spent flowers, you can remove any wilted blooms to keep the plant looking tidy. The berries that follow the flowers are part of the plant’s charm and will attract birds.

Winter Care

• Cold Hardy: Nannyberry is a cold-hardy plant (typically hardy to USDA Zones 2-7), which means it should do well in Lethbridge’s cold winters.
• Protection for Young Plants: Newly planted Nannyberries might benefit from extra protection during the first few winters. Apply a thick layer of mulch around the base of the plant to protect the roots from freezing. If you have strong winds, consider wrapping the plant with burlap or using other windbreak measures.
• Snow Cover: Snow can act as insulation, which is beneficial for Nannyberry, so don’t worry too much if the shrub gets buried under snow. Just be sure to remove any heavy snow buildup that might break the branches.

Pest and Disease Control

• Pest Resistance: Nannyberry is generally pest-resistant, though it can occasionally attract aphids or scale insects. If you notice pests, treat the plant with insecticidal soap or remove affected branches.
• Disease Resistance: Nannyberry is relatively disease-resistant, but it can be prone to issues like powdery mildew or fungal infections in damp conditions. Ensure good air circulation around the plant, and prune away any dead or diseased wood to improve airflow.

Harvesting Berries

• Attractive to Birds: Nannyberry’s berries attract birds in late summer and fall. If you want to harvest the berries for jams, jellies, or baking, wait until they turn blue-black and are fully ripe. The berries may taste tart, but they are edible once ripe.
• Wildlife Consideration: Keep in mind that the berries are a food source for wildlife, so you may want to harvest them before the birds get to them!

General Tips

• Invasive Behavior: Nannyberry is not considered invasive, but it can spread through suckers and may form a thicket if not regularly maintained. If you want to control its spread, trim back any suckers or runners.
• Companion Planting: Nannyberry pairs well with other native shrubs and trees like Silverberry (Elaeagnus commutata) or Serviceberry (Amelanchier), especially if you’re looking to create a diverse, wildlife-friendly landscape.

Conclusion

The Nannyberry is an excellent choice for cold and dry climates, offering both aesthetic and functional benefits. With its cold hardiness, attractive berries, and low maintenance needs, it’s well-suited for your landscape. Ensure it gets the right amount of sunlight, moisture, and protection from harsh winter conditions, and it will thrive, providing beauty and attracting birds to your garden.