Pampas grass, scientifically known as Cortaderia selloana, is a large, ornamental, perennial grass prized for its dramatic plumes and architectural structure in the landscape. Due to its significant mature size, it occasionally requires relocation from its initial planting site. Moving an established clump is a substantial project requiring careful planning and execution. This guide provides the techniques required to ensure the plant’s survival after being transplanted.
Optimal Timing and Site Preparation
The most favorable window for transplanting pampas grass is during its dormant phase, specifically in late winter or very early spring before new growth begins. Moving the plant while it is inactive minimizes the shock to the root system and allows the plant to focus its energy on root establishment rather than supporting new foliage. This timing typically precedes the first signs of green shoots emerging from the crown.
The new location must be selected carefully, ideally providing full, direct sunlight for at least six hours daily to support robust plume production. The soil must offer excellent drainage, as Cortaderia selloana is susceptible to crown rot in consistently waterlogged conditions. Prepare the receiving hole by digging it significantly wider than the expected diameter of the root ball, though maintaining a depth where the crown will sit level with the surrounding grade.
Before beginning the physical work, safety is paramount due to the grass’s razor-sharp leaf margins, which contain silica. Always wear heavy-duty gloves, long sleeves, and eye protection to prevent cuts and abrasions from the serrated edges. Careful handling is required throughout the entire process.
The Excavation and Division Process
To make the plant manageable before excavation, the first step is to drastically prune back the mature foliage. Using loppers or hedge shears, cut all the canes and leaves down to a height of approximately 1 to 2 feet above the soil line. This reduction minimizes the above-ground mass the roots must support during the transplant process and makes maneuvering the clump safer.
Pampas grass develops a dense, fibrous root ball that is notoriously difficult to cut, often requiring specialized tools beyond a standard garden spade. A sharp, heavy-duty spade, a mattock, or even a saw is often required to penetrate the thick, intertwined mass of roots. The extensive root system helps anchor the large grass, making the removal a physically demanding effort.
Begin severing the roots by driving the spade or mattock straight down into the soil in a circle roughly two feet away from the central crown of the plant. Maintaining this distance helps ensure a sufficient volume of feeder roots remains attached to the core mass for successful re-establishment. Rock the tool back and forth to cleanly slice through the tough, woody roots encircling the clump.
Once the perimeter is severed, carefully rock the root ball free from the hole, using leverage to lift the substantial mass. If the entire clump is too large to move or replant, it must be divided into smaller, more manageable sections. Division is accomplished by using the sharp edge of a spade, an axe, or a sturdy saw to cut directly through the crown tissue and the attached root ball. Ensure each divided section retains a sufficient portion of the fibrous roots for independent survival in the new location.
Replanting and Post-Transplant Recovery
Once the division or the main root ball is ready, place the clump into the prepared hole, ensuring the top of the crown sits precisely level with the surrounding soil grade. Planting too deeply can smother the crown, increasing the risk of rot and hindering new shoot development. Position the root ball straight and ensure all sides are in contact with the soil.
Backfill the remaining space around the root ball with the excavated native soil, optionally mixed with a small amount of well-decomposed compost to improve soil structure. Gently tamp the soil down with your hands or the back of the spade to eliminate large air pockets that can dry out the delicate feeder roots. Immediately follow this with a thorough, deep watering to settle the soil and fully hydrate the newly disturbed root system.
The first year post-transplant is the most significant period for recovery and establishment. Maintain consistent moisture, providing deep watering sessions rather than frequent, shallow sprinkles, especially during dry spells. Deep watering encourages the roots to grow outward into the new soil.
Monitor the plant closely for signs of stress, such as wilting or browning. New green shoots emerging from the crown are the clearest sign of successful transplantation. Avoid applying heavy, nitrogen-rich fertilizers immediately after transplanting, as the plant’s energy should be directed toward root development, not excessive top growth.