The Weeping Higan Cherry (Prunus subhirtella ‘Pendula’) is a widely planted ornamental tree prized for its dramatic, cascading branches and early spring blossoms. Gardeners often select this tree to serve as a distinctive focal point in the landscape due to its unique, umbrella-like shape. A common concern among homeowners is whether this beautiful import poses a threat of aggressive, unrestrained growth. Understanding the tree’s official ecological status is the first step in addressing worries about its potential for spread.
Criteria for Determining Invasive Status
The term “invasive” has a precise meaning in ecology, distinguishing it from general garden aggressiveness. A species is classified as non-native, or exotic, if it has been introduced outside of its original range through human activity. Many non-native plants establish themselves and reproduce without human assistance; these are referred to as naturalized species. Naturalized plants are not considered ecologically harmful and integrate without issue into the local environment. A plant becomes truly invasive only when its introduction causes significant environmental or economic harm. Invasive species typically outcompete native flora, disrupting the local food web due to a lack of natural controls. This classification requires evidence of ecological damage, not merely a tendency to spread quickly in a manicured flowerbed.
Ecological Classification of the Weeping Cherry
The Weeping Higan Cherry, native to Japan, is classified as a non-native species in North America. This designation reflects its geographic origin and does not automatically imply an invasive status. The vast majority of weeping cherry cultivars, including ‘Pendula’, are not listed on state or federal invasive species registries. The trees generally lack the aggressive reproductive traits necessary to displace native plants in wild ecosystems. Many ornamental weeping cherry trees are created by grafting the weeping top portion (scion) onto the rootstock of a hardier cherry species. This method often results in a scion that is sterile or produces minimal viable seed, limiting its ability to spread naturally. Therefore, the weeping cherry does not pose the broad threat associated with ecologically damaging invaders.
Nuisance Characteristics and Localized Spread
The concern about the weeping cherry’s aggressive nature usually stems from localized maintenance issues within the home landscape. The most frequent cause of perceived invasiveness is suckering from the tree’s rootstock. Since the weeping variety is typically grafted onto a vigorous root system, this understock often attempts to grow its own straight, non-weeping branches. These suckers emerge from the trunk below the graft union or directly from the roots, and their rapid growth can be mistaken for the entire tree turning aggressive. To manage this behavior, homeowners should prune suckers off cleanly at their point of origin below the graft line. This prevents the energetic rootstock from diverting energy away from the weeping canopy.
The tree produces small, dark, inedible fruits that are consumed and spread by birds. These distributed seeds can germinate, resulting in small volunteer seedlings nearby. However, these seedlings rarely grow true to the ornamental weeping form. Instead, they typically revert to the characteristics of the wild cherry rootstock, which may be perceived as an unwanted sapling in the yard. The Prunus root system is known for being wide-spreading, though it is not destructive to foundations. The roots often compete with turf grass for moisture and nutrients, contributing to the perception of an overly aggressive plant.