Lily Companion Plants: Cool Roots, Sunny Leaves — 7 Pairings and 4 to Skip
Lily companion plants by height: 7 neighbors that keep roots cool and leaves sunny, plus 4 pairings to skip, from lily leaf beetle hosts to cat magnets.
Lilies want their flowers in full sun and their roots in cool, evenly moist soil. Most lists of lily companion plants name a dozen flowers and never say how to get both. The fix is a height rule: low plants under about 20 inches cover the soil, taller ones stand beside or behind, and nothing crowds the lily’s leaves, because leaves that stay wet for 6 to 12 hours in cool weather are how botrytis gets in.
Seven plants below follow that rule. Four pairings break it in ways that cost you bulbs: one is a breeding host for the lily leaf beetle, one fights the soil Oriental lilies need, one gives slugs a hiding place beside the new shoots, and one draws cats toward a plant that can kill them.
What a lily needs from its neighbors
NC State’s Plant Toolbox sums up the setup in one line: full sun to afternoon sun for the leaves, shade for the roots. Six or more hours of direct sun is the standard, and 2 to 6 hours is the floor. The North American Lily Society adds that most lilies prefer full sun but cope with partial shade, and that Oriental types appreciate some shade in hotter climates.
The root half of that advice comes with a number. Iowa State says to keep lily roots cool and consistently moist, but never saturated, with a 2-inch layer of organic mulch around the base. A living groundcover does the same job as mulch, but we found no trial comparing the two on lilies, so treat “feet in the shade” as long-standing practice rather than tested science. Drainage matters more than either: the Lily Society calls it probably the most important condition for a lily’s very life. Our lily watering guide covers how much water that bed should get.
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The leaf half is where companions go wrong. The Pacific Northwest disease handbook says botrytis infection is most likely when plants stay wet for 6 to 12 hours at 50 to 65°F, and its first cultural control is to reduce planting density for air circulation. A neighbor that reaches the lily’s lower leaves traps that moisture. So the working rule is to shade the soil, not the foliage. Our lily disease guide shows what botrytis looks like when it arrives.
7 lily companion plants, sorted by the job they do
Every plant here takes full sun, and all seven grow in USDA zones 5 to 8, which sits inside the zone 4 to 9 range of Asiatic lilies in our guide to the nine lily divisions. Heights, bloom seasons and zones come from NC State’s Plant Toolbox.
| Plant | Job in the bed | Height | Blooms | USDA zones |
|---|---|---|---|---|
| Sweet alyssum | Lowest soil cover, aphid predators | 3–10 in | Spring to fall | Annual |
| Bloody cranesbill (Geranium sanguineum) | Soil cover | 10–20 in | Spring to summer | 3–9 |
| Lamb’s ear | Soil cover, silver foil | 12–18 in | Summer | 4–9 |
| Daylily | Same-sun partner | 1–3 ft | Spring to summer | 3–9 |
| Woodland sage (Salvia nemorosa) | Mid-height spikes, rebloom | 1.5–3 ft | Summer into fall | 4–8 |
| Purple coneflower | Bloom after the lilies | 3–4 ft | Summer | 3–8 |
| Feather reed grass ‘Karl Foerster’ | Upright backdrop | 3–5 ft | Plumes last into winter | 4–11 |
The table’s takeaway: the three plants under 20 inches do the root-shading work, and the four taller ones stand beside or behind the lilies to carry color after the lilies finish.
Low layer: shade the soil
Bloody cranesbill. It’s the safest soil cover because its needs match the lily’s. NC State lists moist, well-drained soil and a pH of 6.0 to 8.0, which covers the 6.0 to 7.0 range Iowa State gives for lilies. It flowers in late spring to early summer, before Asiatic lilies open, and has some susceptibility to leaf spot and rust. Keep a hand’s width between its foliage and the lily stems.
Lamb’s ear. Silver foliage sets off orange, pink and red lilies and stays under 18 inches. The catch is humidity: NC State warns it is susceptible to leaf rot with high humidity or excessive rain, and it prefers soil that is occasionally dry, which is drier than a lily bed. Plant it at the sunny edge, not among the stems, and pull off rotted leaves.
Sweet alyssum. At 3 to 10 inches it’s the lowest cover here. A UC Davis study tested 22 insectary plants and singled out alyssum as the most effective, with aphids suppressed up to 50 feet away by parasitic wasps, green lacewings and syrphid flies. That matters because aphids spread the viruses that ruin lilies (more below). Nobody has tested alyssum on lily virus specifically, so treat the benefit as plausible, not proven.
Middle and back: carry the bloom
Purple coneflower and woodland sage. Asiatic lilies are among the earliest to bloom, while Oriental and trumpet types finish the season in July and August, so the bed needs something to carry it. Coneflower reaches 3 to 4 feet and blooms in summer. Woodland sage runs from summer into fall, and cutting spent stems to the basal leaves brings fresh flowers. Both stay upright enough to sit beside lilies without leaning in. As a general layout guideline, put them on the north side of the bed so they don’t throw shade onto the lily leaves.
Feather reed grass ‘Karl Foerster’. It grows 3 to 5 feet tall but only 1 to 2 feet wide, in a clumping, erect form, so it makes a backdrop without leaning over the lilies. The cultivar is sterile, so it won’t seed into the bed, and the plumes last through most of winter.
Daylily. It wants the same sun, and the University of Wisconsin says lily leaf beetles don’t damage daylilies, so it’s the one lookalike that won’t feed the pest. It isn’t safe for cats, though (see below). Our daylily companion guide covers the bed from the daylily’s side, and daylily vs lily explains why the two aren’t related.
A layout that follows the rule
Give lily bulbs at least 12 inches between small ones and 18 inches between large ones, as the Lily Society advises. Plant the lilies first, at the depth in our lily bulb planting guide, then add companions around them so you aren’t digging near established bulbs. Put alyssum and cranesbill in front and between clusters, sage and coneflower to the sides, and the grass behind.
4 pairings to skip
1. Fritillaria, where the lily leaf beetle lives. The beetle lays its eggs and completes its life cycle only on true lilies and fritillarias, so a fritillary beside your lilies gives larvae a second place to breed. Solomon’s seal and flowering tobacco get only minor feeding, with no breeding. Wisconsin first found the beetle in 2014 and has it in 34 counties after it spread west from New England, so “not in my state” is a shrinking assumption. The adults are about a quarter inch long and bright scarlet, per Mississippi State Extension. Wisconsin’s advice is to hand-pick and crush adults and larvae, crush eggs, and repeat through the season.
2. Lavender beside Oriental lilies. Oriental hybrids need plenty of water, acidic humus-rich soil, and mulch for a cool root run, according to the Lily Society. NC State lists lavender for neutral to alkaline soil, preferably on the dry side. One bed can’t give both. Lavender can share a bed with Asiatics in neutral, free-draining soil, at the drier edge. Our Oriental lily guide explains the acid-soil rule.
3. Hosta skirts and dense mats at the shoots. Clemson says slugs hide by day in thick groundcovers, and it names hostas first among the plants they trouble. Iowa State says slugs damage lily shoots and developing buds. Clemson’s own advice is to remove mulch and leaf litter near vulnerable plants, which sits awkwardly beside Iowa State’s 2-inch lily mulch. A reasonable compromise, and our inference rather than a tested rule, is thin mulch kept off the stems and no dense mat touching the shoots.
4. Catmint, if a cat can reach the bed. The ASPCA warns that eating any part of a lily or daylily, licking pollen off the face, or drinking vase water can cause kidney failure in cats, and that it is often fatal if treatment is delayed longer than 18 hours. NC State says cats find blue catmint attractive. No study tests whether catmint draws a cat to the lily beside it, so that link is our inference, but it’s a poor risk to take. The danger covers the whole bed, daylilies included. Read why lilies kill cats before planting where a cat roams.
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→ View My Garden CalendarWhat companion plants can’t do
No companion has been shown to protect lilies from their worst problems. Iowa State says deer and rabbits often eat emerging lily foliage or bite off stem tops, buds included. Coneflower and feather reed grass are rated deer-resistant themselves, but we found no evidence that they protect a lily planted beside them.
Aphids are the other problem. The Pacific Northwest handbook lists more than 11 lily viruses, says aphids are effective carriers of each of the common ones, and advises removing and destroying affected plants. The RHS lists cucumber mosaic, lily symptomless and tulip breaking virus as aphid-vectored in tulips too, so lilies and tulips share some of the same viruses. If tulips beside your lilies show streaked petals or mottled leaves, pull them out.
FAQ
What should you not plant near lilies?
Skip fritillaria where the lily leaf beetle is present, lavender beside Oriental lilies, dense mats and hosta skirts around the shoots, and catmint if a cat can reach the bed.
Do lilies need shade at the roots?
In practice, yes. NC State advises sun for the leaves and shade for the roots, and Iowa State recommends a 2-inch mulch to keep roots cool and evenly moist. Whether living plants cool the soil better than mulch hasn’t been tested.
What are the best low plants to grow with lilies?
Sweet alyssum (3 to 10 inches), bloody cranesbill (10 to 20 inches) and lamb’s ear (12 to 18 inches) all stay below the lily’s lower leaves. Keep each a hand’s width from the stems for air circulation.
Can you plant lilies and daylilies together?
Yes. They share sun needs, and lily leaf beetles don’t damage daylilies. Both are dangerous to cats, so keep the bed out of reach if a cat lives nearby.
Sources
- NC State Extension. Lilies (Lilium) — Extension Gardener Plant Toolbox
- North American Lily Society. Planting Lilies; Types of Lilies
- Iowa State University Extension and Outreach. Growing Lilies in Iowa — Yard and Garden
- Pacific Northwest Plant Disease Management Handbook. Lily (Lilium spp.) — Botrytis Blight (Fire)
- Pacific Northwest Plant Disease Management Handbook. Lily (Lilium spp.) — Virus Diseases
- Royal Horticultural Society. Tulip viruses — RHS Advice
- University of Maine Cooperative Extension. Lily Leaf Beetle — Home and Garden IPM
- University of Wisconsin–Madison Extension. Lily Leaf Beetle — Horticulture
- Mississippi State University Extension. L.A. Hybrid Lilies for the Farmer Florist (P3818)
- ASPCA. Getting to the Bottom of the Dangers of Easter Lilies
- Clemson Cooperative Extension. Snails and Slugs in the Home Garden — Home & Garden Information Center
- UC Davis. Aphid Relief: Sweet Alyssum
- NC State Extension. Plant Toolbox: Geranium sanguineum; Stachys byzantina; Lobularia maritima; Echinacea purpurea; Salvia nemorosa; Calamagrostis × acutiflora; Lavandula angustifolia; Nepeta × faassenii; Hemerocallis
