Fruit trees can be needy, and gardeners spend a lot of time and energy trying to repel pests, increase harvests, and improve growing conditions. Although there are chemicals that help the process, many growers prefer a more natural route.
Companion planting is a sustainable growth strategy that creates a beneficial ecosystem where fruit trees and other plants take advantage of each other’s strengths and compensate for each other’s weaknesses.
Fruit trees benefit from companion plants that attract pollinators, repel pests, improve soil conditions, conserve water, and suppress weeds. Herbs and wildflowers are the most common companion plants, but legumes, alliums, certain brassicas, and other food crops can help create a diverse ecosystem that benefits both the fruit trees and the companion plants.
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In general, the more diverse an ecosystem, the better. A mixture of plants will introduce a mixture of insects, bacteria, wildlife, and soil organisms. While some may be harmful, most members of an ecosystem are beneficial, and they will form a natural cycle that keeps pests and pathogens from getting out of control.
While almost any plant that flowers or has a strong scent makes a good companion plant, not all companion plants are suitable for all fruit trees.
First, it’s important to know which family your fruit tree is in, and which plants benefit that specific family.
Different Types of Fruit Trees
Anything that flowers will produce fruit. Acorns, locust pods, and even those little helicopters that fall off maple trees are considered fruits. However, the term fruit tree generally refers to trees that produce edible fruits.
There are seven common types of tree fruit (source):
- Pome: fruit forms around a core (apple, pear, loquat)
- Drupe: fleshy fruit forms around a hard seed (olive, peach, coconut)
- Berry: fleshy fruit with a lot of seeds (elderberry, goji berry)
- Aggregate: many small drupes fused together from one flower (mulberry)
- Legume: two-sided pods with seeds inside (carob)
- Hesperidium: a berry with an aromatic rind (citrus)
- Nuts: one seed with a hard shell (pecan, walnut, hazelnut)
While this may seem like a diverse list, these trees have the same fundamental growing requirements:
- Healthy soil
- Pest-free growing environment
Some companion plants will help some trees more than others, but in general, any plant that builds the soil, repels pests, or attracts pollinators will benefit any tree that flowers and produces fruit. For example, see our article on the Best Companion Plants for Pear Trees.
While trees are generally classified according to the type of fruit they produce, they are more accurately classified by family.
Common edible tree fruit families include:
- Star fruit
- Ugli fruit
The most prominent fruit tree families in North America are Rosaceae and Rutaceae.
Rosacea fruits are generally deciduous and grow best in the northern regions of the country, while Rutaceae fruits are generally evergreen and grow best in the southern regions of the country.
How to Find Companion Plants for Your Fruit Trees
Companion plants serve five basic functions:
- Attract pollinators
- Deter pests
- Improve soil
- Smother weeds
- Modify growing conditions
Although there is a wide range of fruit tree families and fruit types, almost all fruit trees benefit from plants that fulfill one or more of these functions.
Fruit trees are either monoecious or dioecious.
Monoecious trees have both male and female flower structures on the same plant.
Dioecious trees have either male or female flowers on a plant.
Monoecious trees can self-pollinate, but most benefit from insects or wind to move pollen to the female flower structures. Dioecious plants must cross-pollinate between male and female trees, which requires insect pollinators in most cases.
Any plant that attracts pollinators will benefit a fruit tree.
First, look up the types of insects that help pollinate your fruit trees. Then, find plants that attract those insects to the area.
Possible pollinators include:
- Honey bees
- Bumble bees
Plants that Attract Bees
Bees are by far the most important pollinator for fruit trees. Plants in the Rosaceae family are especially dependent on honeybees and bumblebees.
Plants that attract bees include:
- Bee balm
- Black-eyed Susan
Plant these plants within 25’ of the tree to attract pollinators. These plants do not have to be as close to the tree as plants that repel pests or improve the soil.
Create a perennial bed or a stand of wildflowers outside of the canopy so the flowers get plenty of sun.
Plants that Attract Butterflies
Butterflies are another important pollinator for fruit trees. Many plants serve double-duty and attract both bees and butterflies:
- Bee Balm
- Blue Wild Indigo
- Butterfly Bush
- Joe-Pye weeds
Part of planting a butterfly garden is planting flowers that are food sources for caterpillars.
Milkweed is the only food source for Monarch butterfly caterpillars. However, some of these plants may be invasive in your area, so check with a local extension agent before you plant them.
Plants that Attract Moths
Moths are often an overlooked nocturnal pollinator. While they aren’t as popular as bees and butterflies, moths play two important roles in an ecosystem:
- Nocturnal pollination
- Food source for beneficial wildlife
Moths are attracted to white or light-colored flowers that open at night. This also happens to be the time when bats, toads, and birds are out hunting.
Small animals also help keep pests in check, and they’re a helpful addition to any companion garden.
However, moth caterpillars can be pests. With the exception of the cabbage white butterfly, all caterpillar damage is attributed to moth caterpillars.
So, while it’s not recommended to plant an entire moth garden, it’s worth planting a few plants to attract moths to bring in small predators and help with pollination.
Plants that attract moths include:
- Four o’clocks
Make sure you place a shallow water dish in your pollinator garden. This not only supplies water to the pollinators but also supplies water to the small predators that feed on pests.
Plants that Attract Wasps, Flies, and Beetles
These insects are far less important to the pollination process than bees, butterflies, and moths. Pollination is more of a secondary role as they peruse the garden looking for pests to eat.
Some beetles are also pests, but by encouraging a diverse ecosystem with plants that attract a lot of different insects and small predators, the pests should be kept in check.
Flies, on the other hand, are an incredibly beneficial predator in the garden. There are over 100,000 species of flies, and many of them feed on aphids and other nuisance pests in the garden.
Plants that attract wasps include:
- Lemon Balm
- Cool-colored flowers (white, blue, purple)
Plants that attract flies include:
Plants that attract beetles include:
- Queen Anne’s Lace
Although wasps, flies, and beetles aren’t the best pollinators, they help to create a diverse ecosystem where pollinators thrive.
If you have limited space, plant flowers that attract many different insects, and set out a few shallow water dishes to make it nice and homey.
Less than 1% of insect species cause damage to plants (source). However, these one-percenters can wreak havoc on a garden lacking beneficial, predatory insects.
There is a twofold approach to using companion plants to repel pests:
- Attract predatory insects
- Use strong-smelling plants to deter pests
Many predatory insects are most useful in the larval stage. For example, ladybugs are a powerhouse against aphids. Ladybug larvae can eat up to 250 aphids in a single day, while adults eat 20-25 per day.
Wasps, flies, and beetles are the best predatory insects.
Use plants that attract wasps, flies, and beetles to encourage breeding in your companion garden.
Use mulch to provide shelter for eggs and larva, and try to avoid spraying or using other control measures if you see pests in your companion garden.
Pests provide food for predatory insects. As long as an infestation doesn’t get out of control, allow pests to live in the garden to sustain the breeding cycle of predators.
Strong-smelling plants are a natural repellent for pests. Many herbs and alliums deter harmful insects and provide a shield for more vulnerable plants.
These plants must be planted close to a fruit tree to provide protection. You can try planting creeping thyme as a groundcover, or placing containers of mint near the drip line.
Onions and garlic can tolerate partial shade, so they can be planted closer to the trunk.
Any mixture of herbs and alliums will help deter pests, and many will also attract predatory insects. Shade-tolerant herbs and alliums have the added benefit of being able to grow close to the trunk to provide better protection.
Plants that deter pests include:
- Lemon Balm
- Lemon Grass
- Lemon Verbena
The plants on this list have the added benefit of being incredibly useful in the kitchen.
Create full-sun and part-shade herb gardens and sprinkle some alliums in, and you’ve got a perfect natural pest-repellent shield for your fruit trees.
Typical fruit trees, like those found in the Rosacea and Rutaceae family, have shallow root systems. Most have taproots from 10’-15’ deep, and lateral roots no more than 8’ deep. Feeder roots, which are responsible for most of the water and nutrient absorption, grow within the top few feet of soil.
Nut trees and other fruit trees may have extensive and extremely deep root systems, but most feeder roots are still in the top few feet of topsoil.
Companion plants can help improve the topsoil and increase aeration in the subsoil. However, there is a balance between using plants to improve the soil and making sure companion plants aren’t competing for water and nutrients. This is why most soil-improvement companion plants are limited to cover crops.
Cover crops are sacrificial crops that are cut down or tilled into the soil before they go to seed. Most cover crops are legumes, because legumes have a unique ability to pull nitrogen out of the air and fix it into the soil.
Brassicas, like mustard and radish, may cause a buildup of soil-borne viruses. These viruses only affect other brassicas, but you should rotate between different plant families to avoid problems in the future.
Cover crops provide a range of benefits for the soil (source):
- Prevent erosion
- Increase soil microbe activity
- Prevent excess evaporation & runoff
- Prevent compaction
- Return nutrients to the soil
Some common cover crops include:
Grasses are a common agricultural cover crop, but they take much longer to break down and they can be harder to establish.
Legumes and brassicas break down quickly, which provides nutrients to the soil faster.
Companion plants can also help suppress weeds. A thick carpet of clover or mustard can smother weed seedlings. A dense stand of wildflowers can shade out grasses.
The key to weed suppression is limiting shade and space. Any plant can be used for weed suppression as long as it is planted close to other plants.
Cover crops are the best for weed suppression because they form a dense carpet. However, stands of wildflowers or herb gardens can be effective if they shade out the soil.
Modify Growing Conditions
Occasionally, companion plants can be used to create microclimates for other plants. For example, tall plants can create shade for shorter, shade-loving plants. Leggy or architectural plants can provide a natural trellis for vines.
Fruit trees can be companions for shade-loving plants.
While most companion plantings revolve around improving the environment for the tree, we can’t ignore the beneficial environment provided by the tree’s canopy.
Onions, leafy greens, some herbs, and a few flowers benefit from shady conditions. Most of these plants offer plenty of benefits in return.
Instead of trying to nurture full-sun plants in a less-than-ideal environment, use the shady space under the canopy to create a beautiful shade garden that builds a diverse ecosystem.
How to Plant Companion Plants
Companion planting is all about using variety to your benefit. Therefore, you want to use as many different companion plants as possible as opposed to filling the space around your fruit trees with one other species.
There are two ways to install companion plants:
- According to the season
- According to the space
Companion plants are effective at different times of the year. Flowering plants promote pollination, but only when the fruit tree is blooming. Plants that repel pests are most useful when pests are active- not in the middle of winter.
Plants are also effective in different places near the tree. Plants close to the tree can improve soil, conserve water, and suppress weeds. Plants farther away attract pollinators.
When you install companion plants, treat them like any other garden. Make a plan for each plant and where it will grow best.
If you try to force sunflowers to do well in a shady spot by the trunk, you will end up with sickly sunflowers. Not only do they not attract pollinators, but they will most likely attract pests.
Plant each companion plant in the best location to create a healthy, thriving ecosystem.
Create a crop rotation plan like you would for your vegetable garden. If you use mustard (a brassica) for a cover crop in the spring, rotate with a legume in the fall.
Plant flowers that bloom the same time as your fruit tree, and rotate them with onions or garlic for pest protection and a fall crop of alliums.
Don’t assume companion plants can only be beneficial. If you neglect a garden of companion plants, it will become a magnet for pests and pathogens. Stressed, sickly plants will do more harm than no plants at all.
Perennials make excellent, low-maintenance companion plants. If you want a less intensive companion garden, create a few beds with herbs and perennial flowers, and keep the beds weeded, mulched, and watered. They will attract beneficial pollinators and predators, which is the most important factor in a companion garden for fruit trees.
Raised Beds, Planters, & In-Ground Beds
Some companion plants, like cover crops, should be planted directly into the soil. Others, like mint, may become an invasive nightmare if you don’t keep it contained to a container.
Use a variety of garden beds around your fruit trees to keep your companion plants where they belong, and to give them the best possible growing environment.
Raised beds are perfect for most companion plants. Alliums, herbs, and flowers thrive in raised beds, and the height makes them easy to care for.
There are a few things to consider before you place raised beds under or near the canopy of your fruit tree:
- Ease of harvesting
- Ease of pruning
Harvesting and pruning require ample space under the tree’s canopy to maneuver around the branches. When you install raised beds, make sure you account for space to place a ladder and other equipment you may need.
When you build or install a raised bed, make sure you use materials that won’t leach chemicals into the soil. This is less important in vegetable beds where the surrounding topsoil is used for pathways, but if the raised beds are near the root system of a fruit tree, you have to be more cautious.
Railroad ties, treated wood, and some paints or finishes may leach into the topsoil and harm feeder roots. Use plastic or natural wood to reduce the chemicals that may get into the soil.
Planters are perfect for companion plants that provide a huge benefit but also a huge risk. Or, in other words, plants in the Lamiaceae family:
- Bee balm
- Lemon balm
Some plants in this family, like basil and rosemary, are less aggressive. Mint is by far the most invasive plant in this family, but the benefits outweigh the work of keeping it contained.
Mint attracts bees and butterflies, and the strong aroma deters pests. It also attracts predatory insects, which provides another layer of pest protection.
Mint is a useful companion plant because it provides an abundance of flavorful tea leaves, and in many climate zones, it’s perennial, so you don’t have to replant each year.
However, anyone who has had the misfortune of planting mint directly into a garden bed knows how it takes over all open soil and finds its way into the dusty crevices of a sidewalk.
We highly recommend this amazing companion plant, but keep it in the planter.
Most companion plants work better in raised beds, but cover crops must be planted directly in the soil.
Because the whole point of a cover crop is to improve the soil. If you fill a raised bed with clover, it’s going to do wonders for the raised bed, but absolutely nothing for the root system of the fruit tree.
Remember to leave space for cover crops if you want to install raised beds, and vice versa. You can walk on most cover crops, so you don’t have to plan out additional pathways unless you want a more formal, permanent look.
Caring for Companion Plants
Companion plants require just as much work as any other garden or landscape plant.
Use compost in the spring, use mulch when you plant, and keep the garden weeded and watered. One well-tended companion plant does more good than ten neglected ones.
As you care for the companion gardens, don’t forget that the goal is to create a healthy environment for a healthy tree.
Don’t put the needs of companion plants over the needs of the fruit tree. Water the soil as necessary for the tree. Fertilize as necessary for the tree. Prune as necessary for the tree. If the companion plants suffer, move them.