Conservation plantings are successful if healthy seedlings, adapted to the site are used. Transplanting is a great shock to live plants and great care must be taken to protect the seedlings. Seedlings planted incorrectly have little chance of survival. The following information will help you care for your seedlings and achieve high seedling survival rates.
Pickup, Transport and Storing
Always pick up your seedlings the day they are dropped off in your county. Most remote drop points do not have proper seedling storage facilities and the quality of improperly stored seedlings deteriorates rapidly. The interval from seedling drop off to planting should be minimized, ideally 24 to 72 hours. Delivery dates are arranged in advance to allow you to organize your time and be ready to receive your seedlings. All site prep, equipment, supplies and labor should be ready by the pick up date.
If possible, transport your seedlings in an enclosed vehicle. If the back of a pickup truck or an exposed trailer is your only option, be sure to cover the seedlings with a tarp. This will keep seedling packages out of direct sun and protect them from drying in the wind. When transporting seedlings never park in the direct sun. Even in the boxes or bales seedlings can heat up to damaging temperatures in the sun. Do not throw or drop the boxes and bales. The seedlings can be damaged from bruising.
Be ready to plant when your seedlings arrive. It is not recommended to store seedlings for more than seven days unless you have access to refrigerated storage. The optimum short-term storage temperatures are 32 to 45 degrees. Never allow seedlings to freeze or expose seedlings to temperatures above 60 degrees unless they will be planted immediately. Store seedlings in a cool, humid location. Root cellars, crawl spaces, basements, and unheated barns work well for short time periods although shelf-life and subsequent out-planting success depends on prevailing temperatures and humidity. At higher elevations, a snow cache works well for temporary storage. Never store seedlings inside vehicles.
Store seedlings in their unopened boxes or bundles until they are planted. Bareroot seedlings should be checked every 2 to 4 days to insure the roots and sphagnum moss packing material remain moist. Periodically check containerized seedlings to be sure the root plugs remain damp. If necessary rewet the sphagnum or root plugs with light watering, don't over water. Roots should be obviously moist with no standing water in the bottom of packages. Evergreen species usually require more frequent watering than deciduous plants with no leaves.
Planting Site Preparation
The goal of site prep is to create an area that is favorable for seedling survival and growth. Favorable seedling sites have high soil moisture level, little competing vegetation, some protection from direct sun and wind, and soils with high organic matter, proper PH, good aeration or texture, and the ability to catch and hold moisture. The best site preparation requires planning up to one year in advance. In the dry areas of Eastern Montana early site prep is critical for high seedling survival.
On most planting sites in Montana, water is the greatest limiting factor to survival. Reducing or eliminating weeds and grasses in your planting area is extremely important. Soil moisture levels can be greatly enhanced by plowing and discing the site a year in advance and keeping it weed free for the entire growing season. Eliminating moisture robbing weeds allows all precipitation to be stored in the soil. Organic mulches or compost can be worked into the soil the season prior to planting to increase organic matter. Be careful with uncomposted manures, as they can be too "hot" for seedlings. If possible, irrigate the site in the fall to ensure good soil moisture the next spring.
Herbicides are also effective in controlling weeds. Glyphosate products kill all existing vegetation without leaving an herbicide residual in the soil. Be very careful when using any pre-emergent herbicides that will persist in the soil. Consult with a pesticide specialist to make certain these herbicides will not harm the seedlings. Follow all label directions exactly with all pesticide products. As with cultivation, it is best to start chemical weed control a year in advance. If there are difficult to control weeds such as thistle or bindweed on the site, it is imperative that you control them well before planting.
In very dry areas, it is beneficial to create small water-catching areas in the fall to enhance early survival. Snow fences can be set up in rows to trap snow on the planting site. Grading a wide and shallow V-shaped trench where seedling row will be planted directs water to where it is most beneficial. Do not make water catchment basins too deep as soil will slough in and bury seedling roots too deep.
Seedling Care at the Planting Site
During all seedling handling the roots must be protected from heat and drying. It is best to keep the seedlings inside the boxes and bundles in which they are shipped right up to the time of planting. Only bring the seedlings that can be planted in one day to the site. At the planting site locate a cool, shaded spot to cache the seedlings.
Minimize the time roots are exposed to sun and air. You can accomplish this with tree planting bags or a slurry bucket. A root dip of soil and water can be mixed for bareroot seedlings. The slurry should have the consistency of thick paint. Roots can also be wrapped in wet burlap. Only carry the seedlings that can be planted in one hour. Do not leave seedlings in the slurry mix longer than 2 hours or root death may occur. Containerized trees can be kept in their poly bags during planting but do not allow direct sunlight to heat up the roots in the bags. Wet the plugs if necessary.
In Montana the best time to plant is early spring to take advantage of high soil moisture levels and cool temperatures. Planting can begin soon after the ground has thawed. The ideal temperature range to plant is 33 to 55 degrees. Freezing temperatures can damage exposed plant roots. If it is warmer than 60 degrees or becomes windy, it is usually best to stop planting and wait for conditions to improve. Fall planting is also an option with container stock but only if rains have rewetted the soil profile. We do not recommend fall planting after the soil temperature drops below 45 degrees, usually sometime in October.
Many types of planting tools are available. A sharp shooter type shovel works well for digging narrow deep holes. Each planting hole must be large enough to accommodate the root system in a natural form. Holes should be six to twelve inches in diameter and at least two inches deeper than the seedling root system. Place the seedling in the hole spreading the roots downward and horizontally. Do not bunch roots at the bottom of the hole or fold them so that the roots ends are directed toward the surface. This is called j-rooting and is a primary cause of seedling mortality.
Incorrect planting depth is another primary cause of poor seedling survival. For bareroot seedlings the root collar (soil surface line when the seedling was in the nursery beds) must be located at the soil surface when finished. Fill the hole halfway with soil and tamp around the roots with your hand. Then, backfill the rest of the hole quickly checking for correct root collar depth and tamp the soil firmly around the roots. Correct backfilling will create good contact between the roots and the soil and remove all air pockets without excessive compacting.
Containerized seedlings are planted the same way with one exception. Containerized seedlings are grown in a peat moss soil mix that dries rapidly. We recommend planting these seedlings to the surface of the plug soil is a half-inch below final grade. Capping the peat soil with native soil will prevent rapid drying of the plug.
Don't put water in the planting holes immediately prior to planting. This can lead to excessive compaction when the soil is tamped around the roots.
Woven weed fabric is recommended as the best method for conserving water around the plant roots and controlling weeds. Studies have shown that weed fabric greatly increases survival and growth rates even over supplemental irrigation.
Dig holes the same day you plant so the holes do not dry out.
If you use a mechanical tree planter have someone follow behind the planter to adjust root collar depth and tamp out air pockets. Mechanical tree planters can be rented from many Conservation Districts.
Select good microsites for the seedlings. Plant on the north and east side of downed logs or stumps to shade the seedling, especially on south slopes. Avoid areas of dense sod.
Remove all weeds and grass from an 18-inch area around each planting hole by scalping with a hoe.