by Julie Whitacre, Fourth Corner Nurseries

Fourth Corner Nurseries is primarily a bare-root nursery, with a limited selection of northwest native plants in containers. We sell our bare-root plants to many growers who use them in container stock.

Bare-root seedlings are inexpensive and range in size from a few inches to 4 feet tall. Bare-root transplants are from one to six feet tall, and slightly more expensive than seedlings. These typically have a more developed root system, larger caliper and more branching than seedlings (Photo 1, Physocarpus transplant and seedling). Comparing plants of equal size, those in containers are more expensive than bare-root plants (seedlings or transplants) due to growing costs. If price is your primary consideration, bare-root plants can be used, but timing and handling considerations must be factored in. Woody-stemmed bare-root plants are available only during the dormant season. Bare-root trees or shrubs will not work if you are required to plant in October. Appropriate handling is also necessary for plant survival.

Well-rooted container plants can be used any month when soil moisture is adequate. They are the preferred choice for late spring to early fall plantings.

Trees and shrubs are harvested bare-root starting in late November through mid-March. These can be kept dormant in a cooler for planting later into the spring. December and January are good months to plant if the ground is not frozen solid and the site is not exposed to frigid, desiccating winds. In some soil types, frost heave can also occur to plants installed at this time. February through early March is typically a great time to plant bare-root trees and shrubs (In western Washington and Oregon). Later in March and April, bare-root can still be planted out into the field, but this can be chancy because survival is dependent on uncertain spring rains to give the plants time with ample moisture to become established. With irrigation, or on reliably moist sites, planting through April is fine. In a nursery setting, potting bare-root trees and shrubs into containers or into irrigated fields can occur anytime bare-root is available. East of the Cascades, the planting window is a little earlier in November and later in March, based on spring thaw and less anticipated rain during the growing season.

Bare-root harvest may start in December, but to ensure availability it’s always a good idea to order in advance – starting in July – for shipping during the dormant season. In some years, some species may be difficult to find by January or February. For projects requiring large quantities, specific sizes, or specific seed sources, custom propagation might be the best option. This requires at least 18-24 months of lead-time or more, depending on seed availability and desired size.

Standard age notation for bare-root plants has two numbers. For example: 1-2 indicates a three-year-old plant that spent 1 season as seedling and 2 seasons as a transplant.

Proper handling after the plants have been delivered or picked up is very important. When storing bare-root plants, avoid exposing roots to the open air. Plants arriving in dormant condition and packaged in paper bags may be kept in a humid, well-ventilated cold storage area at 33-39 degrees F until planting. Inspect plants frequently for moisture levels, mold growth, and bud-break; plants that have broken dormancy must be planted as soon as possible for best results. If cold storage is not available, remove packaging and heel plants into moist sawdust, straw, or soil (Photos 2 and 3, cooler storage and sawdust bed storage). Broadleaf evergreens typically do not fare well in cold storage. For best results, keep these in a cool, moist, shaded area and plant as soon as possible. Soaking roots prior to transplanting is recommended.

Herbaceous plants are harvested bare-root from early April through November. We harvest these by order only, so storage out of the ground during the growing season is minimized (Photo 4, bare root Carex and Eleocharis). Please give us at least one to two weeks notice to assemble an order before shipping is required.

Emergents (sedges, rushes, and bulrushes) seem to transplant best in the spring (April-May) and fall (September-October,) with spring appearing preferred in field-trials at our nursery. Theoretically, emergents can be planted anytime there is sufficient soil moisture (and will be for a few months following installation,) but site conditions such as hydrology, soil type, and weed competition play a large role in survival. Remember that newly-planted seedlings may not survive the hydrology that mature plants can, and may be lost soon after planting. It may be necessary to restrict or delay the flooding of wetland areas for a year or so to allow the plants to become established. Choosing species appropriate to the hydrology of the site is crucial to survival whether bare-root or other stock types are used. Contour maps that show levels of inundation and soil saturation during the growing season are useful in planning revegetation. On projects with both woody-stemmed and herbaceous species, native wetland grasses and forbs may be introduced to complete the landscape after the trees and shrubs are established. In a nursery setting, potting bare-root emergents into containers or into irrigated fields can occur anytime. Emergents harvested bare-root in the summer and potted into containers will often lose all new growth (die back to the soil line) and then resprout.

Herbaceous perennials from drier habitats are also available bare-root, but the timing is more restricted, and is species-specific. Many species transplant best in the spring (April) others in the late summer or early fall (August-October.) Bulbs are harvested and shipped from August through October only. Many of our perennials, especially the irises, delphiniums, and lomatiums, transplant bare-root best at this time also. When you call us with a specific plant list, we’ll work out the best timing to meet your and the plants’ needs.