Liriope muscari ‘Big Blue’ is an ornamental perennial, often mistaken for grass due to its arching, strap-like foliage. This plant, commonly known as lilyturf, is a popular choice for defining garden spaces and providing year-round texture. It is a clumping variety, meaning its expansion is contained and predictable. This growth habit allows it to form dense, manageable mounds, providing reliable groundcover without the invasive tendencies of other liriope species.
Understanding the Growth Habit of ‘Big Blue’
The contained growth of ‘Big Blue’ is determined by its root structure. This cultivar utilizes short, thick underground stems known as pachymorph rhizomes. These rhizomes ensure that new growth emerges immediately next to the parent plant, resulting in a gradually expanding, tight clump rather than a sprawling mat.
This mechanism contrasts with the running habit of Liriope spicata, which relies on long, thin leptomorph rhizomes that send new shoots meters away. ‘Big Blue’ typically expands outward at a slow to moderate rate, reaching a mature spread of about 12 to 24 inches. This slow movement allows it to maintain its dense, mounding form, which is desirable for controlled landscape designs. Clumps slowly increase in diameter, forming a solid, tufted mass of dark green foliage.
The dense root mass also helps the plant resist weed pressure. While the plant spreads, it is not considered invasive because its expansion is limited to a slow, controlled periphery. This manageable growth rate makes it the preferred choice over running varieties of lilyturf. Its overall dimensions remain predictable, making it easy to incorporate into established garden beds.
Managing Clump Expansion and Division
Because ‘Big Blue’ clumps, division is a maintenance choice for propagation or rejuvenation, not a necessity for containment. Gardeners typically divide the plant when the center of the clump looks less vigorous or when they wish to create new plants. This process is effective due to the plant’s robust, tuberous root system.
The best time to divide ‘Big Blue’ is in the late winter or early spring, just before new growth begins. To divide a clump, first dig up the entire root ball using a sharp spade. The dense, fibrous roots are tight, requiring a sturdy tool like a serrated knife or a sharp shovel to cut through the mass.
Once lifted, the main clump can be separated into smaller sections, called divisions or crowns, each containing foliage and a portion of the root system. Each division should be replanted immediately into prepared soil at the same depth as the original plant. Division is an economical way to propagate the plant, as a single mature clump can yield numerous new plants. Splitting congested clumps every few years helps maintain the vigor and appearance of the planting.
Ideal Landscape Uses for Clumping Liriope
The contained, clumping habit of ‘Big Blue’ makes it suited for landscape applications where a defined boundary or controlled groundcover is desired. It excels as an edging plant, creating a neat, formal line along walkways, garden beds, or foundation plantings. Its predictable spread ensures it will not encroach onto paved surfaces or neighboring plants.
For mass plantings, ‘Big Blue’ is superior to running varieties because its clumps eventually merge to form a uniform, dense carpet that stays within the designated area. This is useful for controlling erosion on slopes or filling in large areas under trees where turf grass struggles. The plant also performs well in containers, as its contained root system prevents it from quickly becoming root-bound or outgrowing its pot.
The plant’s dark green, grassy texture provides contrast to broader-leafed perennials and shrubs, adding depth to garden design. Its tidy, mounding shape remains consistent throughout the year, offering evergreen interest in milder climates. Using ‘Big Blue’ for borders and groundcover leverages its slow-spreading growth, guaranteeing a low-maintenance, polished look.