Ornamental grasses offer texture and movement to the landscape. These plants generally need to be transplanted for one of three reasons: the clump has become overcrowded and is showing a dead center, the gardener intends to divide the plant for propagation, or the grass needs to be relocated due to garden design changes. Understanding the proper timing and execution of the transplant process helps ensure the continued vigor and health of these grasses.
Pre-Transplant Planning and Preparation
The success of transplanting ornamental grasses is closely linked to performing the task when the plant is not actively growing under stressful conditions. For most varieties, this optimal timing falls either in early spring or in the early fall. Early spring, just before or as new shoots begin to emerge, is preferred because it allows the plant to establish a root system before the intense heat of summer arrives.
Cool-season grasses, such as Blue Fescue, perform best with a spring division or an early fall move, allowing at least six weeks for root establishment before the first hard frost. Warm-season grasses, including Maiden Grass and Switchgrass, should be divided in late spring or early summer once the soil has warmed and new growth is a few inches tall. Transplanting during the peak summer heat should be avoided, as the stress on the plant is significantly higher.
Before any digging begins, the foliage on the existing grass clump should be cut back severely to a height of about six to twelve inches. This action minimizes the surface area for transpiration, significantly reducing the risk of dehydration during the move. The new planting location must be prepared, ideally offering the full sun and well-drained soil that most ornamental grasses prefer. The receiving hole should be dug wide enough to accommodate the divided root mass and be no deeper than the original planting depth. To make the excavation easier, the parent plant should receive a deep watering one to two days before the scheduled move, softening the surrounding soil and hydrating the root mass.
Excavation and Root Division Techniques
The process of removing the grass clump begins by using a sharp spade to sever the roots in a wide circle around the plant’s base. This circumference should be generous enough to capture a substantial root ball, typically extending six to eight inches out from the crown for small to medium clumps. The spade should be driven vertically and deeply into the soil, cutting through the perimeter roots cleanly before leveraging the entire mass out of the ground.
Once the root mass is loosened, the dense, often heavy clump must be carefully lifted. For large, mature grasses, this may require two people or the use of a tarp to help slide the root ball out of the hole. The dense, fibrous nature of ornamental grass roots necessitates aggressive tools for division.
A sharp, flat-edged spade or a specialized root saw are often the most effective instruments for slicing the root ball into smaller, manageable sections. Each resulting division must contain a healthy portion of the crown, where the roots and new shoots meet, and a sufficient mass of healthy roots to ensure survival. Any dead material from the center of the original clump should be discarded, and the newly separated divisions should be kept shaded and moist until they are immediately replanted.
Reinstallation and Immediate Aftercare
The divided grass sections must be reinstalled promptly into the prepared holes to minimize root exposure and transplant shock. The planting depth requires attention, as the crown of the grass must be set at the same level as, or slightly higher than, it was in its original location. Planting the crown too deeply can lead to rot and hinder new growth.
After positioning the division, the hole should be backfilled with the excavated soil, ensuring that the soil is gently tamped around the roots to eliminate large air pockets. Removing these voids allows the roots to make immediate contact with the soil, which is necessary for water and nutrient uptake. A thorough and deep watering is required immediately following reinstallation.
This initial soaking settles the soil firmly around the new root system and helps to relieve the immediate stress of the move. A two to four-inch layer of organic mulch should be applied around the base of the newly planted grass. It is important to keep the mulch several inches away from the plant’s crown to prevent moisture buildup that could lead to fungal issues or rot.
Ensuring Successful Establishment
The first few weeks after transplanting are a recovery period during which a consistent watering regime is necessary for the plant to establish. Newly planted divisions require frequent watering to encourage the formation of new root hairs that absorb moisture and nutrients. For the first month, the soil should be kept consistently moist, but not saturated, often requiring watering every few days, especially in the absence of rain.
The goal is to provide deep, infrequent watering once the grass begins to show signs of establishment, promoting the growth of a deep, drought-tolerant root system. Gardeners should monitor the plant closely for signs of transplant shock, such as wilting or browning foliage, which indicates the root system is struggling. While a temporary setback is common, persistent wilting requires an adjustment to the watering schedule.
It is advised to avoid heavy fertilization immediately after transplanting. Introducing high levels of nitrogen or other nutrients can stress the already damaged and recovering roots, forcing the plant to focus energy on foliage production rather than root growth. New divisions typically root and begin to show vigorous new growth within four to six weeks, signaling the successful transition to their new location.