Bare root perennials are plants harvested from the field while completely dormant. They are shipped without any soil around their roots. This method offers several advantages, including a significantly lower cost compared to potted plants because there is no soil or heavy container involved. Bare roots are also lighter and easier to ship, and they often possess a larger, more established root system. When planted correctly during their dormant phase, they experience minimal transplant shock and establish quickly.
Determining the Ideal Planting Window
The optimal time to plant bare root perennials directly relates to the plant’s natural dormancy cycle and the condition of the soil. Planting must occur before the plant breaks dormancy and begins to sprout foliage, which typically happens in early spring. The ground should be thawed and workable, but not excessively wet or frozen.
The ideal environment for new root growth is a cool soil temperature, generally ranging between 40°F and 56°F. Planting during this cooler period encourages the plant to focus its energy on developing a robust root system before the demand for top growth begins. If planting is delayed until the weather is consistently warm, the plant will struggle to establish roots while simultaneously trying to support new leaves, which can lead to failure.
While spring is the most common time, fall planting is an alternative for many hardy perennials, provided it is done six to eight weeks before the ground freezes solid. This timing offers a similar advantage of cool soil for root establishment. However, the majority of bare root stock is shipped in the spring to capitalize on the natural cycle of growth before the summer heat arrives.
Handling and Preparing Bare Roots
Upon receiving a bare root order, open the package immediately and inspect the roots for firmness and moisture. If the roots feel dry, they require immediate rehydration. Soak the entire root mass in tepid water for 30 minutes to a few hours, though soaking for longer than 24 hours can be detrimental.
If immediate planting is not possible, temporary storage is necessary to keep the roots dormant and moist. A cool, dark, and non-freezing location, such as an unheated garage or refrigerator, is suitable for short delays. For longer delays, the roots can be “heeled in,” which involves temporarily burying them in loose soil or damp sand in a shaded spot.
Before moving to the planting site, examine the roots again and use clean shears to trim away any roots that appear damaged, broken, or moldy. Making a fresh cut on any excessively long roots can stimulate new root growth. The packing material should be discarded.
Planting Techniques for Success
The physical act of planting a bare root perennial requires careful attention to the root structure and planting depth. Begin by digging a hole that is significantly wider than the spread of the roots, often two to three times the width, but not much deeper than the root mass itself. This wide hole encourages new roots to extend easily into the surrounding, loosened soil.
In the center of the hole, create a small, firm cone or mound of soil and gently drape the roots over this mound, spreading them downward and outward. The most important consideration is the placement of the crown, which is the point where the roots meet the stem or dormant buds. The crown should be positioned level with, or only very slightly below, the surrounding soil surface to prevent rot.
Backfill the hole with the original soil, working it carefully around the roots to eliminate air pockets. Gently firm the soil with your hands to settle the plant, avoiding heavy tamping that could damage the root system. Finish the process with a thorough, deep watering to further settle the soil and provide initial moisture.
After watering, a two-inch layer of organic mulch, such as shredded bark or compost, can be applied around the plant to conserve soil moisture and regulate temperature. Keep the mulch pulled back a few inches from the immediate crown. This gap prevents moisture from collecting against the stem tissue, which helps prevent fungal issues and crown rot.