- Planting Tomatoes Sideways: A Guide to Trench Planting - April 8, 2022
- How to Tell if Potting Soil is Bad - January 22, 2022
- Herbs That Don’t Grow Well Together - October 16, 2021
Companion planting is an excellent, natural gardening strategy for warding off pests and diseases, increasing pollination, and cultivating nutrients.
There are a number of companion plants that help peach trees by repelling pests and enriching the soil.
The best companion plants for peach trees are garlic, marigolds, onions, asparagus, legumes, and tansy. These plants help keep pests away from peach trees and add nutrients to the soil. Other helpful plants include herbs, like chives and basil, and wildflowers, which boost pollination.
Let’s take a look at what exactly companion planting is before discussing how to implement this method for your peach trees.
What is Companion Planting?
Companion planting is the practice of putting plants together that benefit from each other (source). It establishes an environment where plants use each other’s strengths and compensate for each other’s weaknesses. Common benefits include:
- Increasing pollination
- Keeping pests and animals away
- Enriching soil
- Providing shade
- Reducing weeds
For example, some pungent plants – like garlic – repel certain insects like maggots and borers. Those insects are harmful to your fruit trees, so placing garlic close to the fruit trees will keep the insects away from the tree as well.
In return, garlic – especially in hot climates – may need some protection from the afternoon sun. They can get this protection under the edge of the tree’s branches.
Tips for Companion Planting
This is an effective method when it’s done correctly. Some tips to keep in mind are:
- Choose plants that do not compete for nutrients
- Look for plants that support each other’s needs (e.g. beans provide nitrogen to corn, and corn provides climbing support for beans)
- Make sure the roots will not intertwine, but –
- Keep the plant roots close enough to benefit from each other (if you plan on using the plants to enrich the soil; you may not)
- Check for “antagonist” plants (plants that will work against each other)
Best Companion Plants for Peach Trees
Different fruit trees often use the same kind of companion plants. However, there are a few plants that stand out as particularly helpful for peach trees.
The best companion plants for peach trees are:
- Mexican marigolds
Note on Root Depth
Something to keep in mind with peach trees is their shallow root system. Their taproots only reach 5-10 feet deep, with most of their lateral roots congregating around 4’ deep. The roots can spread past the circumference of the drip line, usually stopping around 15 feet from the trunk.
Note on Herbs
Herbs, in general, are easy and multi-functional as companion plants, which makes them extremely popular with gardeners. There are also a few herbs with properties that are specifically beneficial for peach trees.
Companion Plants that Help with Nutrients
Some companion plants help provide nutrients to peach trees. The two most important nutrients for peach trees are potassium and nitrogen (source).
Nitrogen encourages fruit fulfillment and vegetative growth (usually at offsetting times), while potassium helps the fruit to reach its peak size and color. These two elements rely on each other to help the peach tree produce a quality crop.
Legumes have a unique ability to fix nitrogen (convert nitrogen in the air to a form that plants can use) (source). Rhizobia bacteria (the bacteria that transports unusable nitrogen to plants) infects legume roots and create nodules at the ends. The nodules host the nitrogen fixation process and then release plant-available nitrogen into the soil.
Snow/snap peas and pole/snap beans are good legumes for peach trees. Their root systems are shallow enough to not interfere with the peach tree, and they attract beneficial insects like butterflies and bees.
Tansy is an herb that adds potassium to the soil, which is a key nutrient for peach trees. It also helps repel peach tree borers. However, it is a controversial plant.
Tansy is invasive. Check with your local extension office, since it is not permitted in some areas.
If you are allowed to grow it and choose to include it as a companion plant, you must diligently control its growth. Watch for signs of too much potassium in the soil; too much potassium will suppress nitrogen absorption, causing a nitrogen deficiency. Look for yellow leaves and deficient growth.
Tansy is also poisonous and, in some cases, deadly. Keep tansy away from people (especially children) and pets. Generally, it is a plant that can work wonders for peach trees, but only if it’s managed correctly.
Companion Plants that Help with Pests
Other companion plants help peach trees deal with pests. Some of the most common peach tree pests include:
- Peachtree borers: Wasp-like insects that bore into the roots and trunk to nest and feed
- Lesser peachtree borers: Wasp-like insects that bore into the trunk and main limbs
- Nematodes: Tiny, soil-nesting worms that feed on the roots
- Aphids: Insects that feed on the leaves and stems
The best plants to help peach trees resist these pests are:
Mexican marigolds have a uniquely strong, mint/lemon scent that repels flying insects better than other varieties (source). Marigolds in general can also repel nematodes in the soil.
Peach trees are susceptible to root-knot nematodes. These worms invade root systems and cause swelling damage. Once this damage occurs, it is near impossible to reverse. Marigolds can help prevent root-knot nematodes, which is the only reliable protection against these parasites.
The downside to marigolds is that they do attract aphids. However, garlic can help repel aphids, and they do not pose a long-term threat like root-knot nematodes.
Garlic’s most obvious trait is its scent. This is what keeps harmful pests at bay, and it is why gardeners use it as an all-purpose companion plant. For peach trees, it specifically repels borers and aphids.
Sulfur is also a main compound in garlic. This means the soil around the garlic usually contains a good amount of sulfur, which helps fight fungi that can infect peach tree roots.
Onions work just as well as garlic. They are both pungent plants, and they have similar sulfur needs. Alternate onions and garlic throughout the year to provide year-round protection.
Asparagus helps prevent root-knot nematodes as well. It is not quite as helpful as marigolds (they don’t have a repelling scent), and they need extra space away from other plants. However, unlike marigolds, asparagus is an edible companion plant.
Other Beneficial Companion Plants for Peach Trees
Since most peach tree varieties are self-pollinating, they do not require pollination help. However, extra pollination can improve the quality and quantity of the tree’s crop. Companion plants can help this process by attracting bees. These plants include:
- Shallow-rooted herbs
Companion Plants that Boost Pollination
Plants that boost pollination for peach trees are:
Shallow-rooted herbs will not interfere with the peach tree’s root system, and the plants will attract pollinating insects like butterflies and bees. Some herbs provide the additional help of strong smells to deter unwanted insects. A few helpful herbs are basil, oregano, and chamomile.
Wildflowers act in much the same way as herbs. They will not only attract pollinating insects, but will liven up the look of your peach tree. Try using wildflowers like milkweed, daisies, black-eyed Susan, and cosmos to provide food and shelter for monarch butterflies and honeybees.
General Companion Plants for Fruit Trees
Most of the plants listed above have a specific characteristic that helps peach trees. However, peach trees are in the rosaceae family, which includes quite a few fruit trees. These include apricots, cherries, plums, apples, pears, and many others. There are several companion plants that will generally work for rosaceae trees.
Allium Family Root Vegetables
Most members of the allium family (garlic, onions, leeks, chives, etc.) are great companion plants because of their scent. They help repel a wide range of pests.
Cover crops are plants that provide live mulch, nutrients, and weed suppression for other plants. They are smaller, more widespread companion plants. Many cover crops are sacrificial plants, because they get tilled into the ground for mulch. Even so, you can still use many cover crops before tilling them under.
The best cover crops for rosaceae fruit trees are herbs. Their roots are shallow, they exude vibrant scents that attract good pests while repelling harmful ones, they are easy to maintain, and you can use them during their growth period. In addition to the herbs listed throughout the article, dill, fennel, parsley, and mint tend to attract good pests, particularly those that eat unwanted pests.
Flowers are another great cover crop for fruit trees. They liven up the area, attract pollinators with their scent, you don’t lose an edible crop if you till them for mulch. Helpful flowers include nasturtiums, violets, marigolds, daisies, and Queen Anne’s lace.
As you plan your companion plants, there are a few things to keep in mind.
Pick plants with shallow roots.
- Everything on this list has a root system that works with peach trees. If you decide on other plants, remember that peach trees also have shallow roots. You don’t want plants that reach deep enough to compete with the peach tree.
Think about how companion plants could react to each other.
- Just because these plants all help peach trees does not mean they will work well together. For example:
- Garlic stunts the growth of legumes and asparagus
- Each asparagus plant needs 2ft² of space, so you won’t have much room for other plants
- Beans and peas don’t grow well next to marigolds
- Parsley shouldn’t be paired with garlic and onions
- Sage, basil, and rosemary need space from each other
- Oregano can overtake a patch if it roams free
- Sage and onions don’t mix well
- Dill doesn’t grow well with cilantro
Rotate companion plants throughout the year to benefit from plants that may not work well together. For example, plant a cover crop in early spring and till it under when it’s time to plant peas and cool-weather herbs. Plant wildflowers within 30’ of the tree to attract pollinators without interfering with herbs planted closer to the tree. In the fall, plant a crop of garlic and/or a cover crop for winter protection.
In general, plants that attract pollinators can be planted farther away from the tree, while plants that repel pests and improve soil nutrition should be planted closer to the trunk.
Plants Not To Plant With Peach Trees
Some plants have the ability to interfere with the health of a peach tree. These plants may compete for similar nutrients or encourage pests that harm fruit trees and are considered antagonizing plants.
Antagonizing plants would be anything that interferes with a peach tree’s basic needs:
- Protection from pests like peachtree borers, aphids, and nematodes
- Protection from diseases
Research plants that either need the same nutrients, attract those pests, or spread those diseases. For example:
- Brassicas need large amounts of nitrogen and potassium, so these plants would compete for nutrients.
- Small fruits like raspberries need lots of potassium; avoid planting them near peach trees.
- Early cabbage attracts aphids.
- Other fruit trees like plum, apricot, and cherry trees attract peachtree borers.
- Tomatoes and okra are sensitive to root-knot nematodes.
- Don’t plant other fruit trees in the rosaceae family close to each other. These fruit trees need the same nutrients. Peach trees need about 20 feet of space from familial trees.
- Tomatoes, raspberries, and potatoes can spread blight, which can decay peach trees.
- Peppers can carry Verticillium wilt, a pairing of two fungi that kills peach trees. The fungi infect the roots and block water absorption.
Creating a Companion Planting Plan
To create a companion planting plan for your peach tree, think about your goals. Do you want to eliminate chemicals? Do you want to use natural nutrients instead of fertilizer? Are you growing crops to sell? Do you want to maximize your available planting space? Each goal requires a slightly different plan.
- If you want to use as few chemicals as possible, you’ll need plants that repel pests. Marigolds, garlic and onions, asparagus, and most herbs will do the trick. However, garlic and onions will stunt asparagus and parsley, and asparagus needs ample room.
- If you want natural nutrients instead of fertilizer, use plants that deliver nitrogen and potassium. Cover crops would also provide live mulch. Legumes, tansy, marigolds, and most herbs would do well with this. Remember, beans and peas are sensitive to marigolds, and sage, basil, and rosemary need space from each other. Tansy is also invasive and may not be permitted in your area.
- If you’re growing crops to sell and you aren’t concerned with using your companion plant, stick to cover crops. These will be your herbs and flowers. Along with the advice above, remember that oregano is a bit invasive.
- If you just want to make the most of the ground beneath your peach tree, keep spacing in mind. Refer to the “planting tips” to help with spacing.
Companion planting is a great way to encourage a natural and sustainable environment for your peach tree. Garlic, certain legumes, Mexican marigolds, onions, tansy, herbs, and wildflowers serve peach trees in a variety of ways. With the proper planning, your peach tree can host a garden that works together to produce healthy crops for you to enjoy.