A volunteer plant is a seedling that appears unexpectedly in your garden, sprouting from a seed that was not intentionally planted. These plants originate from seeds dispersed naturally, often overwintering in the soil and successfully germinating when conditions become favorable. Volunteers offer a free plant that has already proved its ability to thrive in the specific soil and microclimate of your space. The term applies to garden favorites like vegetables and flowers, which spontaneously self-seed.
Defining Volunteer Plants and Their Unexpected Origin
Volunteer plants are defined by their unplanned self-seeding, typically being a desirable species that has germinated in an unintended location. This spontaneous growth is distinct from common weeds, which are defined as any plant growing where it is not wanted. Unlike an invasive species, which is a non-native plant causing economic or environmental harm, a volunteer is usually a familiar cultivar or flower.
A volunteer’s appearance involves both seed dispersal and seed dormancy. Seeds are distributed through natural vectors like wind or water, or by animals through the consumption and excretion of fruit (e.g., tomatoes or squash).
Many vegetable volunteers appear near compost piles or in garden beds where fallen fruit or unpicked plants decomposed. Seed dormancy is a natural mechanism where the seed delays germination until environmental conditions are optimal. This delay ensures the seed survives the winter or dry periods, only breaking dormancy and sprouting when the temperature and moisture are right for successful establishment.
Practical Steps for Identifying Volunteer Plants
Identifying a young volunteer requires careful observation of its location and early morphology. Location is a strong clue, especially if the seedling appears near a previous year’s crop or in an area enriched with compost. For instance, a tomato volunteer often sprouts where a ripe fruit dropped or in a section recently amended with kitchen-scrap compost.
Visual identification focuses on the difference between the cotyledons and the true leaves. Cotyledons, or “seed leaves,” are the first structures to emerge; they are simple shapes that do not resemble the mature plant’s foliage. These leaves serve as a temporary energy source for the seedling.
The first true leaves appear after the cotyledons and look like a miniature version of the adult plant’s leaves. For example, a volunteer squash seedling will have large, oval cotyledons, but its first true leaves will exhibit the characteristic lobed shape and fuzzy texture of mature squash. Comparing the true leaves to images of known seedlings confirms its identity before it becomes too large to move or remove.
Managing and Cultivating Volunteer Plants
Once identified, the decision to keep a volunteer depends on its location, available space, and acceptance of genetic variation. If the volunteer is situated in an open area where it will not crowd out other plants, allowing it to grow in place is the easiest option, saving it from transplant shock.
Transplanting to a more suitable location is best done when the seedling has its first true leaves and the weather is cool, such as on an overcast day. To minimize stress, the soil in the new location should be moist and loose. Dig up the plant with as much of its root ball intact as possible. Gently place the seedling into the prepared hole at the original depth, followed by thorough watering to settle the roots and reduce transplant shock.
Volunteers grown from hybrid parent plants may not “come true” due to cross-pollination. The resulting fruit or flower may revert to characteristics of a less desirable variety, potentially yielding an unexpected size, flavor, or appearance. If volunteers are too numerous, poorly situated, or if genetic variation is unacceptable, removal is necessary to prevent overcrowding and ensure resources go to intentionally planted crops.