- 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
Today’s gardeners often look for safe, natural ways to care for their crops.
Companion planting is a practice that uses plants to produce nutrients, repel diseases and pests, encourage pollination, and suppress weeds. You can provide your pear tree with these benefits by using specific companion plants.
The best companion plants for pear trees are members of the allium family, lavender, dandelions, most herbs (especially borage), clover, mustard, nasturtiums, aster family flowers like African marigolds and chrysanthemums, and other pear trees.
Before delving into the specifics of pear tree companion plants, let’s look at what companion planting is.
What is Companion Planting?
Companion planting is the practice of putting plants together that benefit from each other (source). This will create an ecosystem of plants that use each other’s helpful properties and protect each other from their vulnerabilities.
Companion planting can provide:
- Increased pollination
- Protection from pests and diseases
- Enriched soil
- Weed suppression
- Better use of space
For example, leeks (a member of the allium family) help repel pests and prevent scab, a fungal infection, for pear trees. In return, pear trees provide shade for leeks so their stalks stay white.
Tips for Companion Planting
Companion planting is not an exact science, but there is some strategy to it.
- Neighboring plants should not compete for nutrients
- Know which plants are “antagonizers” (plants that will harm each other)
- Rotate crops that don’t work well together
- Try to pick plants that both benefit from the pairing (put flowers that need shade under trees that need help with pollination)
- You might need a “sacrificial crop” (a crop that serves another plant; for example, some plants attract pests and give their life so a neighboring plant remains pest-free)
- Spacing is important; some plants need ample space, others need proximity to feed off of each other’s nutrients
Best Companion Plants for Pear Trees
Pear trees are in the Rosaceae family, which includes trees like apples, plums, cherries, almonds, and peaches, among others. These trees share many companion plants, but each tree has a few specific vulnerabilities that call for a customized companion planting list.
The best companion plants for pear trees are:
- Allium family members
- Specific herbs: borage, cilantro, and dill
- Common herbs: including, but not limited to basil, oregano, rosemary, and thyme
- Flowers: nasturtiums and aster family members (marigolds and chrysanthemums)
- Other pear trees
These plants help pear trees by:
- Attracting pollinating insects
- Attracting bugs that eat pear tree pests
- Repelling pests
- Providing nutrients and live mulch
Most of these companion plants have cross-over benefits. For example, most herbs will attract pollinators, and a few of them will attract bugs that eat pear tree pests. Flowers will attract beneficial bugs, but some of them also provide protection against pests.
Pear Tree Characteristics to Keep in Mind
There are a few characteristics of pear trees to remember as you decided on your companion plants.
Pear trees have an extremely shallow root system (sometimes less than 2 feet), but their lateral roots can grow out farther than other fruit tree roots. Remember this when you plan for spacing your companion plants.
For the most part, pears are not self-pollinating and will need another pear tree. They will also need plants that encourage pollinating insects like bees.
A few pear tree varieties – like 20th Century and Bartlett – are self-pollinating, but they are more prolific when nearby plants attract butterflies and bees.
Companion Plants that Help with Pollination
Many of the suggested pear tree companion plants attract pollinating insects. This is one of the main benefits that gardeners should look for in companion plants for pear trees.
Your pollination companion plants should attract insects such as:
That being said, the most important pollinating companion plant for a pear tree is another pear tree.
Other Pear Trees
First and foremost, pear trees need other pear trees to cross-pollinate.
Fruit trees need at least 20 feet of space from other fruit trees to keep their root systems separate, but pear trees need a cross-pollinator available within 100 feet.
Pear trees need a cross-pollinator of a different variety that produces blooms around the same time.
Refer to this cross-pollinating guide to help you decide which pear trees to pair together.
Generally, common herbs (oregano, thyme, sage, basil, etc.) are a great cover crop. They will attract pollinators with their scents, and they work well with most plants as long as they are not invasive.
There are no common herbs that “antagonize” your pear tree. There are a few that don’t grow well together (like basil and sage) and a couple that are invasive (like oregano), but with proper spacing, they will all benefit your pear tree. However, borage tops the list as a pear tree favorite.
Borage is a bit of a wonder plant for pears because it serves several purposes.
It is an herb with a beautiful, bright blue flower. Pear tree owners love it because it attracts pollinating insects, especially bees, with its fresh cucumber scent and it also serves as a great live mulch.
Because borage’s roots are deep and pear tree roots are shallow, plant it on the outside of the tree’s drip line.
Other Pollinator Helpers
Aster family flowers, nasturtiums, clover, dandelions, and lavender all bring in pollinating insects.
Companion Plants that Attract Pest-Eating Insects
Pear trees have specific pests that can cause serious harm to both the tree and the fruit. They are:
- Pear Psylla: small, winged insects that transfer phytoplasma (a bacterial parasite) to the tree, causing general deterioration
- Codling Moths: pests that inject larvae into the pear, which then burrow in the fruit and feed off the center
- Leaf Rollers: a moth that rolls pear leaves up in silk webbing and feeds off the fruits and leaves
- Aphids: feed off of pears and create mold on them by secreting honeydew on the leaves
These pests do have predators that will help control their population. You’ll want plants that attract insects like ladybugs, lacewings, ants, hoverflies, and wasps to eat these pests.
Dandelions, borage, dill, cilantro, lavender, and nasturtiums all attract a combination of these bugs.
For more information, see Do Pear Trees Lose Their Leaves? 5 Key Causes & Preventions
Companion Plants that Repel Pests
Another way companion plants help pear trees with pests is to repel them. They usually do this by emitting pungent odors, but a few of them use chemicals in the root system to repel root pests.
Aster Family Flowers
French marigolds emit a strong scent that comes from a compound called thiophene (a sulfur-containing chemical)(source.) This compound kills root-lesion nematodes (worm-like pests that steal a plant’s nutrients by targeting its roots). Pear trees are particularly susceptible to this kind of root nematode.
Chrysanthemums are known for repelling nasty pests of all sorts. They are a great general companion plant, but for pear trees, they specifically repel aphids and root nematodes.
Mustard is a nutrient-rich cover crop when it is tilled under. It has compounds that, when ground up, will kill root nematodes and harmful fungi in the soil.
Nasturtiums are a common companion plant for fruit trees. They help pear trees by repelling the codling moth, which is their most common pest.
Members of the Allium Family
Allium family members include garlic, onion, leeks, and chives, among others. All of these plants emit strong scents and repel aphids, codling moths, and pear psylla.
Companion Plants that Help with Nutrients and Live Mulch
The two main nutrients that fruit trees need are nitrogen and potassium. Generally, there are a few nutrient-rich cover crops that provide these and other nutrients as well as live mulch for pear trees.
Plants for Potassium and Nitrogen
Good plants for these specific nutrients include borage, red and white clover, and dandelions.
Borage is specifically helpful to pear trees because its roots pull in key nutrients (mainly potassium, but also calcium) from the soil.
Its roots penetrate up to 18 inches, which is deep for an herb. This allows them to access nutrients that other herb roots may not reach.
Dandelions work the same way that borage does with its deep root system. Its taproot usually grows up to 18 inches down (old dandelion taproots can get up to 15 feet long), which means they can soak up hard-to-reach nutrients. The roots also aerate deep soil by breaking it apart.
Red and White Clover
Clover is a legume, which is a group of plants known for their ability to fix nitrogen (convert nitrogen in the air to a form that plants can use) (source).
Legumes develop nodes on the ends of their roots that host the Rhizobia bacteria (the bacteria that transports unusable nitrogen to plants). This bacteria infects the roots and produces nitrogen, which then leaks into the surrounding soil.
Live Mulch Cover Crops
Mustard, clover, and most common herbs are wonderful cover crops that enrich the soil with several nutrients when they are tilled under. They also help suppress weeds.
A Note on Nitrogen and Potassium
Pears need a bit more nitrogen than some other Rosaceae trees, but too much nitrogen could reduce the fruit quality.
Watch for excessive vegetation and limited fruit production; this is a sign of nitrogen overload.
Pear tree roots are wide-reaching and usually collect enough potassium for the tree. However, it is good to have a companion plant that helps pull in this nutrient.
Watch for signs of a nitrogen deficiency, as too much potassium will deplete the nitrogen availability. Look for yellow leaves and poor fruit production.
For more information read Do Fruit Trees Need Nitrogen? How Much and When?
Antagonizing Plants for Pear Trees
Some plants will actually harm your pear tree. Plants that require the same nutrients or attract pear tree pests should not be anywhere near your tree.
Pear trees need:
- Protection from pests like codling moths, pear psylla, aphids, and nematodes
- Protection from diseases
Antagonizing plants will interfere with those needs.
- Black walnut and pecan trees are deadly to pear trees because they emit a chemical called juglone (a chemical that induces allelopathy, which is a process that targets a tree’s reproductive system and general livelihood)(source). These trees should not be within 50 feet of each other.
- Brassicas and raspberries deplete nitrogen and potassium from the surrounding soil.
- Apple trees can be a host site for pear psylla and codling moths.
- Tomatoes attract root nematodes.
- Fruit trees in the Rosaceae family steal soil nutrients from each other if they are too close together. Keep them at least 20 feet apart, even if they are cross-pollinating pairs.
- Peppers can spread fungal diseases to fruit trees in general.
Companion Plant Compatibility
When you are designing your companion planting plan, remember:
Think about how companion plants could react to each other.
Just because these plants all help pear trees does not mean they will work well together. On the other hand, some pear tree companion plants will serve as companion plants for each other. For example:
- Allium family members don’t work very well with legumes
- Lavender grows well with marigolds
- Don’t plant allium family members next to each other
- Nasturtiums are versatile and work particularly well with dill
- Sage, basil, and rosemary don’t grow well together
- Mustard grows well with thyme, rosemary, tansy, and onions
- Oregano can get invasive
- Don’t grow onions with sage
- Marigolds grow well with the allium family, chrysanthemums, lavender, and basil
- Cilantro and dill antagonize each other
However, not all of these plants have the same growing seasons.
- Dill Nasturtiums
- Allium Family (besides chives)
Considering the plants’ differing seasons, there are some “bad” pairings that you can avoid by rotating the crops.
For the plants in the same growing season, just make sure they are spaced properly. For example, plants that attract pollinating insects should be planted closer to the drip line than plants that repel pests and act as live mulch or fertilizer.
Creating a Companion Planting Plan
Decide what your goal is for creating a companion planting plan.
Some gardeners want to focus on pollination, others want to introduce natural mulch and fertilization, while some want to protect their trees without the use of chemicals.
Many gardeners want a mix of benefits, which is easy with pear tree companion plants because they are mostly multi-purposed.
- Assuming you already have a cross-pollinating tree close by, you can increase the pollination by introducing aster family flowers, nasturtiums, clover, dandelions, common herbs, borage, and lavender. Keep dill and cilantro separate. Remember that basil, rosemary, and sage need to stay apart, and oregano can become invasive. The flowers on this list all work well with the herbs.
- For natural mulch and fertilization, use mustard, clover, common herbs, borage, and dandelions. Apart from the advice above, this should all work well together.
- If you want to protect your tree from pests with the least amount of chemical possible, use dandelions, borage, aster family flowers, allium family members, mustard, dill, cilantro, lavender, and nasturtiums. Don’t plant allium family members next to each other, sage, or borage.
Pear trees have several companion plants that serve multiple purposes. These plants will help increase pollination, protect the tree against pests, and enrich the soil with needed nutrients. Try experimenting with these companion plants to create the ultimate environment for your pear tree.
You may also be interested in this article: Is a Pear a Fruit or a Vegetable? Facts and Misconceptions