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The first few years after I planted my mulberry trees, I treated the ground beneath them like dead space. I mowed around the trunks, kept the soil bare, and figured the trees would do their own thing. They did — but I was leaving a tremendous amount of value on the table. It took a failed garlic experiment in year four and an accidental clover discovery in year six to make me take companion planting seriously. Twelve years later, the ground beneath and around my seven mulberry trees is one of the most productive and self-sustaining areas of my entire homestead. This post is everything I’ve figured out about companion planting mulberry trees — what works, what doesn’t, and why.
Why Companion Planting Around Mulberries Is Different
Mulberries are not subtle trees. A mature Morus rubra or Morus alba can spread 30 to 40 feet wide and cast deep shade for most of the day. The roots are aggressive, the canopy is dense, and during fruiting season — which on my property runs from late May through early July — the ground under those trees is a constant mess of dropped fruit, foot traffic, and bird activity. Any companion planting strategy has to account for all of that, not just nutrient synergy or pest management theory.
Most companion planting advice is written with vegetable gardens in mind. Mulberry trees exist in a different category. You are working with a long-lived woody perennial that will outlast most of your other plantings by decades. The companions you choose need to tolerate partial to full shade, handle intermittent fruit drop, and not compete aggressively with shallow feeder roots.
The Ground-Level Layer: What I Actually Grow Under the Canopy
White Clover
This is my number one recommendation, and it came to me by accident. In year six, I stopped mowing one section under my largest tree and white clover filled in on its own within a single season. I’ve since intentionally seeded it under all seven trees. White clover fixes atmospheric nitrogen through its relationship with Rhizobium bacteria — a function that directly feeds the shallow root zone of the mulberry. I’ve stopped applying any supplemental nitrogen fertilizer under those trees entirely. The clover also stays low enough to let fallen fruit be visible for harvesting and provides a soft landing that reduces bruising on dropped berries.
Comfrey
I grow Russian comfrey (Symphytum x uplandicum, Bocking 14 variety) in a ring about four feet out from each trunk. Comfrey is a dynamic accumulator — its deep taproot pulls up calcium, potassium, and phosphorus from below the mulberry root zone and deposits those nutrients back at the surface when the leaves are cut and composted in place. I do three chop-and-drop cycles per season. I will give you the honest caveat here: comfrey spreads. Plant it once from root cuttings and it will be there forever. I have a section of my property where I allowed it to run unchecked and it took two full seasons of consistent removal to bring it back under control. Keep it where you want it from the start.
Nasturtiums
I plant nasturtiums every spring along the drip line of my mulberry trees. They serve two purposes. First, they attract aphids away from the tree — nasturtiums are a well-known trap crop for aphid pressure, and in my experience they genuinely do pull pest populations away from the primary plant. Second, they bloom during the same window when my mulberries are fruiting, which keeps pollinators cycling through that zone. The flowers and leaves are also edible, which means they contribute to the overall harvest value of the area.
The Edge Layer: Plants That Work Just Outside the Drip Line
Yarrow
Yarrow grows in the transitional zone between full canopy shade and open ground around three of my trees. It tolerates the dry, partially shaded conditions well, and it draws in predatory wasps and beneficial flies that help control caterpillar and aphid populations on the mulberries. I cut it back once in midsummer and it rebounds quickly. Low maintenance, high value.
Chives and Garlic Chives
I mentioned failing with garlic in year four — the bulbs simply couldn’t handle the root competition and shade that close to the trunk. Chives are a different story. Both common chives and garlic chives handle partial shade well and their allium chemistry is reported to deter certain boring insects. I grow them in clusters at the outer edge of the canopy. They’ve also become a reliable harvest in their own right — my family uses garlic chives in cooking from June through October.
Lemon Balm
Lemon balm is a pollinator magnet and it grows aggressively enough to suppress weeds in the transition zone without much help from me. I keep it cut back to prevent it from self-seeding everywhere, but as a weed suppressor and bee attractor during fruiting season, it earns its place. Research from the University of Minnesota Extension has noted lemon balm’s effectiveness for drawing beneficial insects to orchard environments, and that lines up with what I observe directly.
What I’ve Tried That Didn’t Work
Mint. I planted spearmint under two trees in year three thinking it would suppress weeds and deter pests. It did neither effectively — it just became another aggressive spreader competing for the same root zone. The spearmint won that fight and I spent half of year four pulling it out.
Borage is another one that looked promising on paper. It reseeds itself so prolifically that it became more of a management problem than a solution. If you have the patience to stay on top of it, borage may work for you. I don’t, so I dropped it.
Tall vegetables like tomatoes and squash under the canopy are a complete waste of time. They need direct sun. I tried zucchini in year two because I had run out of space elsewhere. I got two undersized squash and a lot of yellowed leaves.
Mulching as the Foundation of the Whole System
None of these companion plants work as well without good mulch management underneath. I keep a three-inch layer of wood chip or organic mulch under all my trees year-round. This retains soil moisture, moderates temperature, suppresses weed competition, and feeds the soil biology that makes everything else function. I refresh it once in spring and once in fall. The mulch layer is not optional — it is the foundation that makes the companion planting system viable.
What I Use and Recommend
If you are just getting started with companion planting strategy and want a solid reference, Companion Planting for Beginners: Pair Your Plants for a Bountiful, Chemical-Free Vegetable Garden is the most practical guide I’ve found. It’s written for vegetable gardens but the underlying principles — nitrogen fixing, pest deterrence, beneficial insect attraction — apply directly to the edge and transition zones around orchard trees.
When I’m seeding clover or nasturtiums in the spaces between established companions, even spacing makes a measurable difference in how well the plants fill in. The Seeding Square – Patented Seed and Seedling Spacer Tool for Bigger Harvests, Organized Plants & Fewer Weeds takes the guesswork out of it and I’ve used mine for four seasons running.
For the mulch layer I mentioned above, Back to the Roots 25.7qt (1 Cubic ft) Organic Premium Mulch is a reliable option when I need to supplement what I produce from my own wood chips. It breaks down well and doesn’t compact the way some bagged mulches do.
The Bottom Line After Twelve Years
Companion planting mulberry trees is not complicated once you accept the conditions the tree creates and stop fighting them. Work with the shade, work with the root competition, and choose plants that actually thrive in those circumstances. White clover, comfrey, nasturtiums, yarrow, and chives have been the core of my system for years now. The trees are healthier, the soil is better, the pest pressure is lower, and I get secondary harvests from the companion plants themselves. It took a few seasons of failure to find what works — hopefully this saves you some of that time.