Successful pine plantings require a well-prepared site, quality seedlings, proper storage and field care of seedlings, and timely planting by a crew trained in proper planting techniques. Most landowners contract with a vendor for such tree-planting services. This note gives information on (1) key clauses to include in any tree-planting contract and (2) conditions which affect seedling survival and early growth.
The landowner who writes an adequate contract and then monitors the planting operation to insure compliance will most often be rewarded with a successful tree-planting operation.
A written tree-planting contract protects both landowner and contractor from misunderstandings and possible lawsuits. A tree-planting agreement should include specific provisions covering these items:
- acres, price per acre, species, seedling sources, spacing, and planting methods;
- time of planting (preferably a starting and ending date);
- insecticide, fungicide or root-dip requirements—for example, dipping pine seedlings in an insecticide for pales weevil control;
- planting crew ingress and egress;
- time and method of payment;
- map which clearly shows the area to be planted;
- who obtains, transports, stores, and handles seedlings (landowner or contractor);
- provisions requiring the contractor to con tact the landowner once planting begins;
- percentage survival guarantee or guarantee of adequate stocking;
- who performs the seedling survival count and when (date). Generally, the contractor should be liable to replant, at no cost, those areas which fall below an agreed percentage survival specified in the contract unless poor survival can be attributed to one or more of the following conditions:
- seedlings furnished by the landowner;
- species planted not recommended by the North Carolina Forest Service for that planting site;
- grazing by domestic livestock and/or wildlife;
- natural hazards such as wildfire, drought, insects, diseases, freezing, and similar factors;
- inadequate site preparation.
- provisions for settlement of disputes; and
- right of contractor to subcontract to a third party.
Seedlings should be planted upon receipt, but poor weather conditions or unavailability of planting crews often prevent prompt planting. Dormant seedlings can be stored up to 10 weeks in cold storage (32 to 40°F) at a humidity above 80 percent. If cold storage is not available, seedlings can be stored up to 4 weeks in a cool (35 to 40°F) shaded warehouse. Slurry-type root dips or weekly watering of the root systems may extend warehouse storage up to 8 weeks if the seedlings remain dormant.
Protect seedlings from heat and freezing temperatures during cold or warehouse storage. Baled or bagged seedlings will generate heat. Allow adequate air circulation between and around seedlings to avoid overheating.
"Heeling-in" is an outdoor storage method. To heel-in seedlings, remove them from the package and place the root system in a dug furrow. Cover the root system with dirt and mulch and water weekly. Heeling-in is a good method for long-term (over 8 to 10 weeks) storage. The seedlings must be planted before budbreak, as dormant seedlings survive better and produce better early growth.
Field Care of Seedlings
The major cause of plantation failure is improper on-site storage and handling of seedlings. Follow these guidelines:
- Store bags or bales in the shade. Improvise a shelter if necessary.
- Place spacers between bags/bundles to allow air circulation and prevent heat buildup.
- Tightly close bags by folding the flap; secure it with a band or cord. Keep opened bundles moist with wet burlap, moss or other water-holding material.
- Keep seedling roots moist by dipping in water or commercial root dip. Be careful not to puddle water in bags, as this will promote mold or drown root tips.
- Heel-in seedlings if they are to be stored on the site over two days.
Research and experience show that planting poor-quality seedlings leads to excessive mortality and poor early growth. Discard seedlings for any of these reasons:
- Broken, skinned or weak stems.
- Fermented odor or mold on needles.
- Slippery bark on root or stem.
- Root collar diameter smaller than 1⁄4 inch or larger than 3⁄4 inch except longleaf pine, which must be at least ¼ inch in diameter.
- Root system less than 4 to 5 inches long.
- Root system longer than 12 inches if more than 50 percent of the fine roots must be pruned in order to plant.
- Longleaf pine seedlings with tap roots shorter than 7 inches.
- Containerized seedlings with a dry, hard root plug.
- Any seedling with a dry root system resulting from improper storage, exposure to sun and air for over 10 minutes on a cool, humid day or 5 minutes or less on a warm, windy or dry day. Bitter cold, dry winds can be equally destructive.
- Presence of stem galls or swelling which indicate the presence of Cronartium fusiforme, a fungus disease.
In North Carolina, seedlings are available from private and industrial sources as well as the North Carolina Forest Service (NCFS).
Root pruning is done to remove excess fibrous roots. Seedlings should be root pruned to avoid bent root systems in the planting hole. Only trained individuals should perform root pruning using these guidelines:
- Do not expose roots to wind or sun more than five minutes. Keep roots moist at all times. To keep roots moist, dip in water or commercial root dips. If possible, root pruned seedlings at the same time as grading.
- Prune roots to a uniform length by aligning root collars in bunches before pruning.
- Use a sharp knife, machete, ax or hatchet. Never break or twist roots off by hand.
- Do not remove more than 50 percent of the lateral fibrous root system. Root systems on loblolly, shortleaf, Virginia, and white pine seedlings with 5- to 8-inch tops should not be less than 5 inches long. Seedlings with 8- to 12-inch tops should not be root pruned to a root system less than 7 inches long.
- Avoid pruning lateral or tap roots of longleaf pine. Prune only excessively long roots and clip longleaf needles back to 4 to 5 inches at the time of root pruning.
Seedlings may be planted by hand tools or by machine. To be successful, plant quality seedlings at the correct depth with roots extending straight into the planting hole. An 8- to 10-inch straight hole is usually sufficient. "Dibbles" are the most popular hand-planting tools.
Dormant season planting (October through March) is recommended for bare root seedlings, although seedlings in containers may be planted throughout the year. Consult a forester to determine the best planting date for each region of North Carolina.
The following are several key factors to improve early growth and survival:
- Carry seedlings in a canvas bag or bucket containing commercial root dip, mulch or wet sawdust to cover the root system when hand planting. Do not carry seedlings in hand with roots exposed. When machine planting, carry seedlings in a planting box on the planter. Roots may be dipped, covered with wet burlap or mulched in the planting box.
- Carefully separate seedlings to prevent damaging or breaking fibrous roots. Remove only one seedling at a time from the planting bag or box.
Well-drained sites (sand and sandy loams). Plant root collar 2 to 3 inches below groundline except for longleaf pine which should be planted at or very slightly below the root collar.
Poorly Drained Sites (clay and silt soils). Plant root collars one inch below ground line.
Containerized Seedlings. Plant deep enough to cover the top of the container with soil to prevent wicking from drying the plug.
- Close hole properly to insure soil/root contact. Check by pulling tops of seedlings to evaluate how tightly they are held in the hole. Make sure the hole is firmly closed at the bottom. Avoid areas of loose soil or organic matter which often accumulate close to rotting stumps.
- Maintain quality control by frequently checking seedling condition, planting depth, and proper packing of soil.
Publication date: March 1, 2019
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