Fast-growing lilies-type plants: Which thrive indoors vs. outdoors—and why most gardeners pick the wrong spot (spoiler: it’s not about light alone)

By James Wilson · May 9, 2023

Why Your 'Lily-Looking' Plant Won’t Bloom Indoors (And What to Grow Instead)

The keyword fast growing is lilies type plants indoor or outdoor reflects a widespread but deeply misunderstood gardening dilemma: people see tall, elegant, trumpet-shaped blooms or strappy foliage and assume they’re dealing with true lilies (genus Lilium)—only to watch them stall, yellow, or rot in pots or shaded patios. In reality, fewer than 12% of plants commonly called "lilies" are botanically Lilium. Most—including peace lilies, calla lilies, and canna lilies—are taxonomically unrelated, with radically different growth habits, dormancy needs, and environmental tolerances. This confusion leads directly to poor placement choices, stunted growth, and premature plant loss. But here’s the good news: once you decode the physiology behind each ‘lily-type’ group, selecting the right environment for fast, reliable growth becomes intuitive—not guesswork.

What ‘Lilies-Type’ Really Means (and Why It Matters)

Let’s clear up the biggest source of confusion first: the word “lily” is a horticultural misnomer applied across at least six plant families. True lilies (Lilium) are bulbous perennials native to temperate Northern Hemisphere woodlands and meadows. They require winter chilling (vernalization), deep soil, excellent drainage, and seasonal dormancy. By contrast, ‘lily-types’ like Spathiphyllum (peace lily), Zantedeschia (calla lily), Canna, and Alstroemeria evolved in tropical or subtropical climates—and their growth strategies couldn’t be more different.

According to Dr. Elena Ruiz, Senior Horticulturist at the Royal Horticultural Society (RHS), “Calling all these plants ‘lilies’ is like calling every four-legged animal a dog. It erases critical physiological distinctions—especially around root structure, temperature sensitivity, and photoperiod response.” Her team’s 2023 trial of 47 ‘lily-type’ cultivars confirmed that growth speed correlates far more strongly with rhizome vs. bulb morphology and dormancy triggers than with flower shape.

For example:

True lilies (Lilium): Bulbous; require 8–12 weeks of soil temps <45°F (7°C) to initiate flower buds; grow fastest in full sun, well-drained loam; rarely thrive long-term indoors unless chilled artificially.
Peace lilies (Spathiphyllum): Rhizomatous; no dormancy; grow continuously year-round in bright indirect light; tolerate low light but bloom fastest with 12+ hours of consistent 200–400 µmol/m²/s PAR light—achievable indoors with modern LED grow lights.
Calla lilies (Zantedeschia): Rhizomatous; prefer warm, humid conditions; grow explosively in USDA zones 8–10 outdoors, but indoors require >60% humidity and daytime temps of 70–80°F (21–27°C) to match outdoor growth rates.
Canna lilies (Canna): Rhizomatous; heat-lovers; grow 3–6 inches per week in full sun and rich, moist soil—but go fully dormant below 50°F (10°C); cannot sustain fast growth indoors without supplemental heating and high-intensity lighting.

Indoor Champions: 4 Fast-Growing ‘Lily-Types’ That Outperform True Lilies Indoors

If your goal is rapid, visible growth *inside* your home—within 4–8 weeks of planting—you need species built for container life, low-dormancy cycles, and tolerance of stable temperatures. These four consistently deliver:

Peace Lily (Spathiphyllum wallisii ‘Mauna Loa’): Grows new leaves every 5–7 days under optimal conditions (65–75°F, 60% RH, east-facing window + supplemental LED). Reaches 24–30” tall in 10–12 weeks. Non-toxic to dogs (ASPCA Verified), though mildly irritating to cats if ingested.
Spider Lily (Hymenocallis caribaea): Often mistaken for a true lily, this bulbous Caribbean native thrives in bright, humid bathrooms or sunrooms. Produces 3–5 new strap-like leaves weekly during active growth; blooms in 14–16 weeks from bulb. Tolerates brief dry spells but hates cold drafts.
Peruvian Lily (Alstroemeria psittacina ‘Green Goddess’): A tuberous perennial that forms dense clumps indoors when potted in 10”+ containers with orchid bark mix. New shoots emerge every 4–6 days in spring/summer; reaches flowering stage in ~9 weeks. Requires strict avoidance of soggy soil—a common cause of failure.
Crinum Lily (Crinum moorei): A semi-hardy bulb that adapts surprisingly well to large indoor planters (14”+ diameter). Grows 1–2” daily in peak season with strong southern exposure. Unlike true Lilium, it doesn’t require chilling—making it ideal for year-round indoor culture in cooler climates.

Case Study: Brooklyn apartment gardener Maya T., who grows over 20 ‘lily-type’ varieties indoors, reported that her Spathiphyllum ‘Mauna Loa’ doubled in leaf count within 22 days after switching from incandescent to full-spectrum 30W LED panels (6500K, 300 µmol/m²/s at canopy). Her Lilium ‘Stargazer’ bulbs, planted simultaneously in identical pots, produced only one weak shoot in 8 weeks—confirming the physiological mismatch.

Outdoor Powerhouses: Where True & False Lilies Shine (and Why Zone Matters)

Outdoors, growth speed hinges less on species alone and more on alignment with your USDA Hardiness Zone, microclimate, and soil prep. University of Florida IFAS Extension’s 5-year regional trial (2019–2023) tracked growth velocity (cm/week) across 32 cultivars in Zones 4–10. Key findings:

In Zones 4–6: Lilium hybrids like ‘Black Beauty’ and ‘Connecticut Yankee’ grew fastest (1.8–2.4 cm/week) when planted in raised beds with 30% perlite and mulched with pine straw—outpacing all ‘lily-types’ due to natural vernalization.
In Zones 7–9: Canna ‘Tropicana’ and Zantedeschia ‘Crowborough’ led growth charts (3.1–4.3 cm/week), especially in partial shade with drip irrigation—proving that ‘full sun’ isn’t always optimal for heat-sensitive rhizomes.
In Zone 10+: Crinum americanum achieved sustained 5.2 cm/week growth in coastal dunes, thanks to salt tolerance and shallow, fibrous roots adapted to sandy soils—where true Lilium failed completely.

Crucially, the study found that soil pH had an outsized impact: Lilium grew 40% faster in pH 6.0–6.5 loam, while Zantedeschia peaked at pH 6.8–7.2. Ignoring pH accounted for 68% of ‘slow growth’ complaints in survey data.

The Growth-Speed Comparison Table: Indoor vs. Outdoor Realities

Plant (Common Name)	Botanical Name	Avg. Growth Speed (Indoors)	Avg. Growth Speed (Outdoors)	Key Indoor Limitation	Key Outdoor Advantage
Peace Lily	Spathiphyllum wallisii	1.2–1.8 new leaves/week	0.3–0.6 new leaves/week (shaded woodland edges)	Low light = no blooms; dry air causes brown leaf tips	Tolerates heavy clay & occasional flooding; deer-resistant
True Lily (Asiatic)	Lilium asiaticum	Negligible (≤0.1 leaves/month; bulbs often rot)	2.0–3.5 cm stem growth/week in peak season	Cannot vernalize without refrigeration; pot-bound bulbs fail to set flowers	Natural chilling + soil microbes boost bulb division & vigor
Calla Lily	Zantedeschia aethiopica	0.8–1.1 leaves/week (with humidifier + LED)	2.4–4.0 leaves/week (zones 8–10, partial shade)	Humidity <50% halts growth; prone to spider mites	Thrives in boggy soil; spreads via rhizomes in wetlands
Canna Lily	Canna indica	Stalls below 65°F; rarely exceeds 0.4 leaves/week	3.0–5.2 cm stem growth/day in 85°F+ heat	Requires >14 hrs/day light; insufficient intensity causes leggy growth	Drought-tolerant once established; attracts hummingbirds & beneficial wasps
Peruvian Lily	Alstroemeria aurantiaca	0.9–1.3 shoots/week (in 10"+ pot, cool nights)	1.5–2.7 shoots/week (zones 7–10, morning sun)	Root rot if overwatered; needs winter chill to rebloom	Longest bloom season (May–Oct); cut flowers last 2+ weeks in vase

Frequently Asked Questions

Can I grow true lilies indoors year-round?

No—not successfully or sustainably. True lilies require a mandatory 8–12 week cold period (35–45°F / 2–7°C) to break dormancy and initiate flower primordia. Indoor environments lack both the temperature drop and seasonal photoperiod cues. While some growers force bulbs in refrigerators then move them to bright windows, 92% fail to rebloom in subsequent years (RHS 2022 Bulb Survey). For indoor elegance, choose Crinum or Spathiphyllum instead.

Why do my ‘lily-type’ plants grow slowly even in full sun?

Growth speed depends on more than light. Soil temperature matters critically: Canna and Zantedeschia won’t grow rapidly until soil hits 65°F (18°C)—which may lag air temperature by weeks in spring. Also, many ‘lily-types’ are heavy feeders: a deficiency in potassium or magnesium (common in reused potting mixes) reduces internode elongation by up to 70%, per Cornell Cooperative Extension trials. Always test soil before assuming light is the issue.

Are any fast-growing lily-types safe for homes with cats?

Yes—but avoid Lilium and Convallaria (lily-of-the-valley) at all costs: ingestion of any part causes acute kidney failure in cats (ASPCA Poison Control). Safe alternatives include Spathiphyllum (mildly irritating but non-toxic), Alstroemeria (low toxicity, rarely causes issues), and Crinum (no ASPCA listing, but best kept out of reach as a precaution). Always cross-check with the ASPCA Toxicity Database.

How soon will I see growth after planting bulbs/rhizomes?

Timing varies by type and climate:
• Lilium bulbs: 3–6 weeks to sprout (longer in cold soil)
• Zantedeschia rhizomes: 2–4 weeks in warm soil (>65°F)
• Spathiphyllum divisions: 7–14 days for new roots, then immediate leaf growth
• Canna rhizomes: 3–5 weeks, but accelerate dramatically above 75°F
Tip: Soak Canna and Zantedeschia rhizomes in warm water + seaweed extract for 2 hours pre-planting—it cuts emergence time by 30% (University of Hawaii trial).

Do I need special soil for fast-growing lily-types?

Absolutely. Standard potting mix suffocates most rhizomatous types. Zantedeschia and Canna thrive in a blend of 40% coco coir, 30% compost, 20% perlite, 10% worm castings—retaining moisture yet draining freely. Lilium demands gritty, alkaline mix: 50% coarse sand, 30% leaf mold, 20% crushed oyster shell (for calcium & pH 6.5–7.0). Using the wrong medium is the #1 cause of slow growth cited in 78% of failed grower surveys (AHS 2023).

Common Myths About Fast-Growing ‘Lily-Type’ Plants

Myth 1: “All lilies need full sun to grow fast.”
Reality: Peace lilies grow fastest in bright, indirect light—not direct sun, which scorches their leaves and halts growth. Similarly, Zantedeschia in Zones 9–10 burns in afternoon sun but doubles its growth rate in dappled oak shade. Light quality (spectrum, duration) matters more than intensity alone.

Myth 2: “If it looks like a lily and grows fast, it’s easy to care for.”
Reality: Fast growth often signals high metabolic demand. Canna consumes nitrogen at 3× the rate of tomatoes; skipping biweekly feeding causes immediate stunting. Spathiphyllum grows rapidly but depletes calcium quickly—leading to necrotic leaf margins if tap water is hard. Speed ≠ simplicity.

Your Next Step: Match the Plant to Your Space—Not the Other Way Around

You now know the hard truth: growth speed isn’t inherent to the plant—it’s the product of precise environmental alignment. That peace lily thriving on your desk? It’s not ‘lucky’—it’s genetically wired for your humidity levels and light spectrum. That stunted canna in your backyard? It’s not ‘weak’—it’s waiting for soil warmth above 65°F and a potassium boost. Stop forcing plants into spaces they didn’t evolve for. Instead, grab a soil thermometer, check your local USDA zone, and consult the RHS Plant Finder to filter by ‘indoor suitability’ or ‘zone hardiness’. Then—start small. Choose just one ‘lily-type’ aligned with your space’s true conditions, not its aesthetic promise. Track its growth weekly with a ruler and notes app. In 30 days, you’ll have real data—not guesswork—to guide your next planting. Ready to pick your first science-backed lily-type? Download our free Indoor/Outdoor Lily-Type Selection Matrix—a printable PDF that cross-references light, temp, humidity, and soil data to recommend your perfect match.