Eggplant Companion Plants
Eggplant grows best alongside companions that pull their weight. Reliable partners include Sweet alyssum, Dill, Cilantro / coriander, and Buckwheat. Just as important is what to keep apart — avoid planting eggplant near Potato, Tomato, and Black walnut. Every pairing below comes with the specific reason behind it and how to stack them by layer and season.
Grow Eggplant with: Sweet alyssum, Dill, Cilantro / coriander, Buckwheat, and more below.
Keep it away from: Potato, Tomato, Black walnut.
Best companions for Eggplant
Each pairing below earns its place — the reason, when to plant it, and where it sits in the bed.
Alyssum's tiny nectar-rich flowers feed adult hoverflies (Syrphidae) and parasitic wasps whose larvae then consume aphids on nearby eggplant; documented to lower aphid counts by improving the predator-to-pest ratio.
Layout: Transplant or sow alyssum along the bed edges at the same time as eggplant; it blooms quickly and keeps flowering all season for continuous nectar.
Dill's umbel flowers supply nectar and pollen that sustain lady beetles, parasitic wasps and hoverflies; intercropping dill in eggplant is documented to raise lady beetle numbers and lower Colorado potato beetle larval survival.
Layout: Interplant a few dill plants around eggplant and let some bolt to flower when eggplant is fruiting and hornworms/aphids appear.
When allowed to bolt, coriander's flowers rank among the top annual attractors of hoverflies and parasitic wasps in OSU insectary trials, recruiting natural enemies of aphids and caterpillars to the eggplant bed.
Layout: Sow in cool spring and let it bolt as the weather heats and eggplant ramps up; successive sowings keep flowers present through the season.
Fast-blooming buckwheat is a top insectary plant for syrphid flies and parasitic wasps in extension trials; its nectar fuels natural enemies of aphids and beetles while its dense canopy smothers weeds.
Layout: Sow a strip beside eggplant ~5-6 weeks before you need bloom (it flowers in ~4-6 weeks); cut before it sets seed and resow for continuous bloom.
Grown as a dense pre-crop cover, T. patula is a non-host that starves root-knot nematodes (Meloidogyne) and releases nematotoxic alpha-terthienyl from its roots, cutting root galling on the eggplant that follows.
Layout: For nematodes, grow a solid marigold stand (<7 in spacing) on the SAME spot 2+ months before eggplant. Note: a few interplanted marigolds do NOT protect eggplant roots.
As a legume, bush beans fix atmospheric N via rhizobia and their low canopy uses bed space efficiently beside upright eggplant; most fixed N reaches eggplant only after the bean residue is turned in, not by live transfer.
Layout: Interplant bush (not pole) beans between eggplant at similar timing; the biggest soil-N gain comes from cutting and incorporating the plants at season's end.
Basil's aromatic volatiles are traditionally grown with eggplant to deter thrips, whiteflies and flea beetles, but rigorous eggplant-specific data is thin; any effect is likely modest scent-masking rather than strong repellency.
Layout: Interplant basil among eggplant at transplanting; both share the same warm-season, full-sun timing.
Nasturtium is traditionally set out as a trap that aphids often prefer over eggplant, potentially luring them away; documentation is strongest for brassicas, so the eggplant benefit is suggestive rather than proven.
Layout: Set nasturtium a few feet from eggplant so pests colonize it first; it works better in spring. Pull and destroy heavily infested plants.
How to lay it out
Stack companions by layer so they share light, root space, and time instead of competing — the permaculture way to pack more into one bed.
Layers for a Eggplant guild. Tags mark companions planted on a delay so they fill in as the bed matures.
Plants to avoid near Eggplant
Both are nightshades sharing Colorado potato beetle, flea beetles and Verticillium/early blight; adjacent planting concentrates these pests and soilborne pathogens. Keep in separate beds and rotate nightshades on a 3-4 year cycle.
Tomato shares eggplant's Verticillium wilt, bacterial wilt, flea beetles and Colorado potato beetle; planting or rotating these nightshades in the same soil builds up shared pests and pathogens.
Eggplant is highly sensitive to juglone released by black walnut roots and leaves; plants within the 50-80 ft root zone yellow, wilt and die. Keep eggplant well outside the dripline or in a root-barriered raised bed.
Fennel releases allelochemicals (anethole, fenchone) reported to suppress germination and growth of many garden plants; direct eggplant data is lacking, so site fennel apart as a precaution.