The question of how tall lilies grow has no single answer because the term “lily” encompasses a huge diversity of plants belonging to the genus Lilium. Their mature height is highly variable, spanning a range from less than one foot to over eight feet, depending entirely on the specific type of lily planted. This broad spectrum of size reflects natural evolution and extensive hybridization, making the genetic background the primary determinant of a lily’s eventual stature. Understanding the factors that influence this growth, from genetics to environment, is necessary to predict the size a plant will reach.
The Primary Factors Influencing Lily Height
The ultimate height a lily achieves is shaped by both its genetic blueprint and the environmental conditions it experiences. The most significant factor is the specific cultivar or hybrid group, as this determines the inherent maximum height programmed into the plant’s DNA. A dwarf Asiatic lily is genetically predisposed to stay short, regardless of its growing environment.
The quality of the growing conditions plays a supporting role in achieving the plant’s full height potential. Lilies require ample sunlight and well-drained, fertile soil to produce the energy needed for robust stems. A plant grown in poor soil or excessive shade will likely result in a shorter, weaker stalk compared to one planted in ideal conditions.
The age and maturity of the bulb also influence vertical growth. While some types reach maximum height in the first year, many taller hybrids grow progressively larger over several seasons as the underground bulb clump expands. Proper planting depth is also a consideration, as taller varieties require deeper planting for support.
Height Ranges of True Lilies
True lilies belong exclusively to the genus Lilium, and their heights are broadly categorized by their hybrid groups.
Asiatic Hybrids
These are generally the shortest and earliest to bloom, typically growing between one and three feet tall. While most popular varieties fall within this range, some dwarf forms may stay under a foot, and certain vigorous types can reach up to five feet.
Oriental Hybrids
These lilies are prized for their intense fragrance and large, bowl-shaped blooms. They usually mature to a medium height of three to five feet. Hybrids like ‘Stargazer’ are the most recognized within this group for their consistent, mid-range stature.
Martagon Lilies
Often called Turk’s-cap lilies due to their recurved petals, they possess a unique, slender growth habit. They commonly reach a height of three to five feet, bearing multiple small blooms. These lilies are distinct for their tolerance of dappled shade, thriving where other lilies might struggle.
Trumpet and Aurelian Hybrids
The tallest lilies are generally found in this group, easily reaching four to seven feet. The largest specimens, known as Orienpet or OT Hybrids, are a cross between Oriental and Trumpet types, combining size with fragrance. These strong-stemmed hybrids can sometimes exceed eight feet under optimal conditions.
Common Plants Mistaken for Lilies
Many popular garden plants include the word “lily” in their common name but are not members of the Lilium genus, leading to confusion about their height potential.
Daylilies (Hemerocallis)
These are frequently mistaken for true lilies, but they grow from a dense clump of roots rather than a bulb. Their bloom scapes can range from ten inches to over six feet, with many common garden varieties falling between one and a half to four feet tall.
Calla Lilies (Zantedeschia)
These are recognizable by their sleek, funnel-shaped spathes. Calla lilies are generally much shorter than true lilies, typically reaching only one to three feet in height depending on the cultivar. They are native to South Africa and thrive in different conditions than temperate Lilium species.
Peace Lilies (Spathiphyllum)
These are common indoor plants that are unrelated to true lilies. When grown indoors, these plants usually maintain a size between one and four feet tall. However, certain large cultivars can grow up to six feet tall when planted outdoors in tropical climates or given exceptional indoor care.