Clover, belonging to the genus Trifolium, is a group of plants frequently used in lawns, pastures, and agricultural fields worldwide. The question of whether it returns each year does not have a single, simple answer because the term “clover” encompasses many different species, each with its own distinct life cycle. The survival strategy of the plant depends entirely on the specific variety, which dictates its lifespan and how it maintains a presence in the landscape. Understanding the life cycle of the particular clover species present is the first step in knowing if it will regrow.
Understanding Clover Life Cycles
Clover species are categorized into three main life cycles: annual, biennial, and perennial.
Annual Clover
Annual clovers, such as Crimson Clover (Trifolium incarnatum), complete their entire life cycle within one year. They germinate, grow, produce seed, and then the entire plant dies, relying on the successful germination of dropped seeds to return the following year. These varieties are often planted in late summer or fall, grow through the winter, and flower in the spring before dying off in the heat of summer.
Biennial Clover
Biennial species, like some varieties of Red Clover (Trifolium pratense), live for two growing seasons. They establish a root system and foliage in the first year, then flower and produce seed in the second year before dying. Many Red Clover varieties are considered short-lived perennials, sometimes persisting for two to four years under optimal conditions.
Perennial Clover
Perennial clovers, most notably White Clover (Trifolium repens), truly “grow back” from the same plant structure year after year. White Clover can live indefinitely, as its root system survives through the winter and produces new growth when temperatures rise. This longevity makes white clover a common component in long-term lawns and pastures.
How Clover Maintains a Presence in the Landscape
Beyond the life cycle of the individual plant, clover maintains its presence through distinct methods of propagation.
Vegetative Spreading (Stolons)
Perennial White Clover possesses a spreading mechanism called stolons, which are horizontal stems that creep along the soil surface. These stolons store energy and root at the nodes, creating new, genetically identical plants. This ensures the patch expands and survives even if parts of the original plant are damaged.
Reseeding
The success of annual clovers, which lack a stolon system, relies completely on prolific reseeding. Species like Crimson Clover must produce a large number of viable seeds before the parent plant dies at the end of its season. If these seeds successfully germinate the following year, the clover patch reappears, even though the plants are technically new individuals.
Perennial types also contribute to reseeding, especially when allowed to flower fully. Allowing the plant to set seed provides a backup plan for persistence, adding new genetic material to the stand. This dual strategy of vegetative growth via stolons and sexual reproduction via seed allows perennial clovers to be highly persistent.
Conditions for Clover Survival and Regrowth
The successful return of any clover is heavily influenced by external environmental factors. Clover generally thrives in a soil pH range between 6.0 and 7.0. Proper soil conditions are necessary for nutrient availability, especially since clover forms a symbiotic relationship with bacteria to fix its own nitrogen.
Survival through cold periods is another factor, as harsh winters can cause winterkill even in cold-tolerant perennial varieties. The depth of the root system and the insulating layer of snow or debris help determine if the plant crown survives to regrow in the spring.
Maintenance practices also play a role in persistence. Mowing too frequently or too short, especially during hot, dry periods, can stress the plant and deplete the energy reserves stored in the roots and stolons.
For annual and biennial types, mowing must be managed to allow the flowers to mature and drop their seeds, ensuring a stand for the next season. Conversely, frequent mowing in the spring can stimulate stolon production in White Clover, encouraging it to spread more vigorously.