Honeyberry shrub companion plants for soil health

The Sweet Science of Honeyberry Companion Planting

Honeyberries, also known as Haskaps, are increasingly popular for their delicious, antioxidant-rich fruit and their remarkable hardiness. These resilient shrubs thrive in a variety of conditions, but like any plant, they benefit immensely from thoughtful companion planting. Beyond simply filling available space, companion planting with honeyberries focuses on synergistic relationships that improve soil health, deter pests, attract beneficial insects, and ultimately lead to a more abundant and vigorous harvest. This article delves into the art and science of selecting the best companion plants for your honeyberry shrubs, with a particular emphasis on fostering exceptional soil health.

Understanding Honeyberry Needs

Before exploring companion plants, it’s crucial to understand the honeyberry’s fundamental requirements. Honeyberries prefer well-drained, slightly acidic to neutral soil (pH 5.5-7.0). They thrive in full sun to partial shade, though increased sunlight generally leads to better fruiting. They are relatively low-maintenance but can benefit from:

• Consistent moisture, especially during fruit development.
• A layer of organic mulch to retain soil moisture and suppress weeds.
• Nutrient-rich soil, but they are not heavy feeders.

The key to successful companion planting for soil health lies in choosing plants that either directly contribute nutrients to the soil, improve its structure, or foster a beneficial microbial environment without competing aggressively for resources.

Nitrogen Fixers: The Foundation of Soil Fertility

Nitrogen is a critical macronutrient for plant growth, and many soils are deficient in it. Nitrogen-fixing plants are invaluable companions for honeyberries because they have a symbiotic relationship with rhizobia bacteria, which convert atmospheric nitrogen into a usable form for plants. This “free” nitrogen enriches the surrounding soil, benefiting the honeyberry and reducing the need for synthetic fertilizers.

Leguminous Powerhouses

Legumes are the champions of nitrogen fixation. Several can be excellent companions for honeyberries, contributing to soil fertility and offering other benefits.

• Clover (Trifolium spp.): White clover, red clover, and crimson clover are excellent ground covers for the understory of honeyberry bushes. They suppress weeds, attract pollinators, and, most importantly, fix nitrogen. Their shallow root systems generally don’t interfere with honeyberry roots. Crimson clover, in particular, is a fast-growing annual that can be tilled into the soil as a green manure in the fall, further boosting soil organic matter and nitrogen levels.
• Vetch (Vicia spp.): Hairy vetch and common vetch are vigorous nitrogen fixers that can be grown as a cover crop. They are particularly effective at improving soil structure and preventing erosion. While they can be competitive, they should be managed by mowing or cut-and-fall before they become too invasive or start to climb the honeyberry stems.
• Lupins (Lupinus spp.): Many lupin varieties are also nitrogen fixers and add a beautiful splash of color to the garden. They have deep taproots that can help break up compacted soil, improving drainage and aeration. Ensure you choose perennial or reseeding annual varieties that fit your garden’s aesthetic and management style.

Other Nitrogen Contributors

While legumes are the most direct nitrogen fixers, other plants can indirectly contribute. Some dynamic accumulators draw nitrogen from deeper soil layers and make it available at the surface when their leaves decompose.

Root Zone Enhancers: Improving Soil Structure and Nutrient Uptake

Beyond nitrogen, companion plants can significantly improve the physical structure of the soil, enhancing drainage, aeration, and the ability of honeyberry roots to access water and nutrients.

Deep-Rooted Allies

Plants with deep taproots are particularly beneficial for breaking up compacted soil layers. This improves water infiltration and allows air to reach the deeper root zones, creating a healthier environment for the honeyberry.

• Comfrey (Symphytum officinale): Often hailed as a garden superstar, comfrey is a potent dynamic accumulator. Its deep taproot draws up minerals like potassium, phosphorus, and calcium from deep within the soil. When its leaves are chopped and dropped around the base of honeyberry bushes (as “chop and drop” mulch), these nutrients are released as the leaves decompose, enriching the topsoil. Comfrey also attracts pollinators. It’s important to note that Bocking 14 is a sterile variety, preventing unwanted spread through root or seed.
• Daikon Radishes (Raphanus sativus var. longipinnatus): While often grown as a cover crop, daikon radishes with their large, fleshy taproots are excellent at breaking up hardpan layers in the soil. When they decompose, they leave behind channels that improve drainage and aeration. They can be planted in the fall and allowed to freeze and decompose over winter.
• Borage (Borago officinalis): Borage has a deep taproot and is also a dynamic accumulator, particularly of potassium and calcium. Its fuzzy leaves and vibrant blue flowers attract beneficial insects like bees and predatory wasps. Its tendency to self-seed can be managed by deadheading or allowing some to grow.

Ground Covers for Soil Stability

Low-growing, spreading plants act as living mulches, protecting the soil surface from erosion, retaining moisture, and suppressing weed growth. This reduces competition for water and nutrients for the honeyberry.

• Creeping Thyme (Thymus serpyllum): This low-growing herb not only smells wonderful but also attracts beneficial insects. Its dense mat of foliage helps keep the soil cool and moist and deters weeds.
• Chamomile (Matricaria chamomilla/Chamaemelum nobile): Both German and Roman chamomile can form a lovely, fragrant ground cover. They are known to improve the growth and flavor of many plants and attract beneficial insects. They tend to self-seed readily.

Beneficial Insect Attractors: A Natural Defense System

A healthy ecosystem in your garden includes a diverse population of beneficial insects that prey on common honeyberry pests. Companion plants can act as magnets for these helpful allies.

Pollinator Powerhouses

Honeyberries require cross-pollination to produce fruit. While they are attractive to bees, certain companion plants can further enhance pollinator activity.

• Lavender (Lavandula spp.): Highly attractive to bees and other pollinators, lavender also has a lovely fragrance and can tolerate similar growing conditions to honeyberries. Its drought tolerance means it won’t compete heavily for water.
• Mint family (Lamiaceae): Many plants in the mint family, such as oregano, thyme, and sage, are excellent for attracting pollinators and beneficial insects. They are generally hardy and can thrive in similar conditions. Be mindful of vigorous mint varieties and consider planting them in containers sunk into the ground to prevent spreading.
• Sunflower (Helianthus annuus): While large sunflowers might compete for light if planted too close, smaller varieties or those planted at a distance can provide a significant nectar and pollen source for bees. Their deep roots can also help break up soil.

Predator and Parasitoid Attractors

Some plants specifically attract insects that prey on common garden pests like aphids or spider mites.

• Dill (Anethum graveolens): The feathery foliage and umbrella-like flower heads of dill are a magnet for beneficial insects such as ladybugs, lacewings, and predatory wasps, which are natural aphid predators.
• Fennel (Foeniculum vulgare): Similar to dill, fennel’s intricate flowers attract a wide range of beneficial insects. It is also known to repel certain pests, though it can become invasive in some climates.
• Yarrow (Achillea millefolium): Yarrow produces flat-topped clusters of flowers that are highly attractive to ladybugs, hoverflies, and parasitic wasps. It is drought-tolerant and improves soil by drawing up nutrients.

Plants to Avoid or Use with Caution

While many plants can be beneficial, some can be detrimental to honeyberry growth or soil health due to competition or allelopathic properties.

• Walnut trees (Juglans spp.): Walnut trees exude juglone, a chemical that inhibits the growth of many plants, including berries. Avoid planting honeyberries anywhere near walnut trees.
• Brassicas (cabbage family): While not directly harmful, brassicas can be heavy feeders and may compete with honeyberries for nutrients. They also attract different sets of pests, which might not be beneficial for the overall ecosystem.
• Plants requiring vastly different soil pH: Avoid companions that thrive in highly acidic or alkaline conditions, as this will complicate soil management for your honeyberries.
• Highly aggressive spreaders: Be cautious with plants that spread aggressively via runners or seeds, such as some mint varieties or ground covers, as they can quickly overwhelm and outcompete the honeyberry plants themselves. Containment strategies, like root barriers or careful monitoring, might be necessary.

Implementing Companion Planting Strategies

Successful companion planting involves more than just scattering seeds. Consider the following:

1. Site Assessment and Planning

Observe your honeyberry patch. Are there areas that tend to be more compacted? Are certain areas prone to weed overgrowth? Do you have issues with specific pests or a lack of pollinators? Plan your companion plantings based on these observations and the needs of your honeyberries.

2. Spacing and Competition Management

Ensure that companion plants are spaced appropriately to avoid excessive competition for light, water, and nutrients. For ground covers, keep them trimmed back from the immediate base of the honeyberry stems. For taller nitrogen fixers like vetch or lupins, manage their growth by mowing or cutting them back before they become too dominant or start to shade the honeyberries excessively.

3. Rotation and Succession Planting

Consider rotating your companion plants. For example, planting a nitrogen-fixing cover crop like crimson clover in the fall and tilling it in before spring planting can significantly improve soil fertility for the upcoming season. Succession planting, where you sow companion plants at different times, can ensure a continuous supply of benefits and attract a wider range of beneficial insects throughout the growing season.

4. Mulching with Companion Plant Material

Utilize the “chop and drop” method with plants like comfrey, borage, and clover. After mowing them down, leave the cuttings as a nutrient-rich mulch around your honeyberry bushes. This not only feeds the soil but also helps retain moisture and suppress weeds.

5. Observation and Adaptation

The best companion planting strategies are often discovered through observation and adaptation. Pay attention to how your honeyberry plants respond to their companions. Are they growing more vigorously? Is the soil structure improving? Are beneficial insects more prevalent? Adjust your choices and methods based on what you observe in your specific garden environment.

Conclusion: A Synergistic Approach to Honeyberry Cultivation

Companion planting is a holistic approach that extends the benefits of honeyberry cultivation beyond just fruit production. By strategically selecting plants that fix nitrogen, improve soil structure, and attract beneficial insects, you create a self-sustaining ecosystem that supports robust honeyberry growth and significantly enhances soil health. This ecological approach not only leads to healthier plants and a more bountiful harvest but also contributes to a more resilient and vibrant garden environment. Embrace the power of synergistic planting and watch your honeyberry patch flourish, nourished by the very earth it grows from.