Handling of Bare Root Perennials

Many perennials ordered from nurseries are bare root plants. These plants are subject to the stresses of being dug from the field, held in cold storage, shipped long distances under varying conditions, and are frequently held in temporary storage before being planted at their final destination. There are several things that home gardeners can do to ensure the survival and growth of the plants that they order.

Determine a shipment's quality upon arrival. If the crowns and roots are covered with molds, are rotted, or are very dry, it is unlikely that the plant will grow well. Give it a try if you'd like, but be prepared for disappointment. Notify the nursery of your receipt of poor quality plants. This will simplify a later request for a refund or replacement, if necessary. If the roots are turgid and light in color, little or no mold is present, and the crowns and roots are in good physical condition, odds are good that the plant will do well if properly planted. If the plant appears somewhere between these two conditions, the subsequent regrowth of the plant becomes more of a judgement call. A partial covering of surface mold may be unsightly, but the plant may be healthy enough to make satisfactory growth. Research has shown that when surface molds cover 50 percent of the plant or less, the potential for regrowth is not affected. Regrowth quality does decrease as surface molds increase, and when soft rotting molds or bacterial infections are present, regrowth is unlikely.

Plant perennials as soon as possible after delivery. If you cannot plant immediately, store them properly until you can plant. Moisture loss is the greatest threat to the survival of bare root plants. Exposure to room temperature and humidity will cause bare root plants to lose as much as two to three percent of their fresh weight in moisture every hour. Such an exposure for even overnight can easily result in the plant's death. Preventing desiccation should be your highest priority in handling bare root perennials. If you must wait to plant, keep them in the poly bags in which they were shipped. These bags allow adequate exchange of oxygen and carbon dioxide when the plants are kept at cool temperatures, so don't open the bags so the plants can "breathe." Don't give them a drink, either, as free water in the bags will promote the growth of molds and bacteria.

High temperatures can also lower plant regrowth quality. Store the plants in your refrigerator, as close to but not below 32 deg. F, as you can, until you are ready to plant them. If the plants have been allowed to warm significantly above storage temperatures, condensation in the bags upon recooling may be a problem. Leave the bags open as they cool to the storage temperature, then close them again. Some moisture loss will occur, but the amount of mold promoting condensate on the inside of the bags will be reduced.

Continue to protect the regrowth quality of bare root plants even while planting them. Keep them in their shipping bags until planting time. Shade the bags so the roots will not heat up. Don't leave an unprotected plant lying on the ground while preparing the planting hole. Dessication can occur rapidly on a sunny and breezy spring day. Water the plant thoroughly to settle it into the soil and get it off to a good start.