Tree Planting by William R. Sayward, Owner/Manager Itasca Greenhouse, Inc.
The best time to plant a tree or forest or windbreak was 20 or more years ago, the next best time is now. Tree planting is very rewarding and productive. As a youngster I helped plant thousands of seedlings on our family’s woodlots and on neighbor’s lands in Vermont. Most of these plantations have produced nice productive stands of timber that are 30 to 40 years old and coming to their prime. The well maintained plantations have already produced forest products through commercial thinning. This gives me and my family a lot of gratification. Likewise having started millions of seedlings which have been out planted successfully by my former employer and our customers has been very gratifying.
Over time millions of trees have been planted, but probably more plantations have failed than have been successful. If plantations are not installed within numerous limiting parameters, they can lead to miserable failures, replanting, poor performance and slow growth. Anybody can plant a tree, but there is more to planting than putting a seedling in the ground and walking away. Before one considers planting there are some steps or guidelines that should be considered. Some of the more important ones are as follows, and will be expanded upon later in the presentation.
- What is the objective of that planting?
- Evaluate your site, and match it to the species that will perform on the site.
- What type of site preparation is needed to insure better survival and growth?
- What type of planting stock is going to be used?
- What season are the trees going to be planted?
- What planting method is going to be used?
- Is protection from animal damage needed?
- Special treatments that may increase survival and growth.
1. What is the objective of the planting? There are numerous reasons and combinations of reasons to plant trees. They may include developing better wildlife habitat; a shelter belt to break up the wind and reduce snow drifting; a timber stand; controlling erodiable land (stabilizing land); aesthetics; short rotation production for fiber; cover for recreation; specialty products; and the list goes on.
When the objectives are decided upon one should pre-plan the installation of the plantation. There are many places that one can go to get help in preplanning a plantation: The local consulting forester; government foresters; PFM forest assistance programs from local forest industries; soil and water conservation districts; university extensions agencies; nurseries; and cooperatives just to name a few sources of information and assistance. It is best if you get assistance if you are not experienced in tree planting. Your plantations are more likely to fulfill your goals and objectives. Many people have tried to reinvent the “wheel” and have more failures than they care to talk about. If they had recruited the assistance from experienced personnel, their chance of success would have been much better. Learning by the “school of hard knocks” can be painful, discouraging and costly.
2. Evaluate your site, and match it to the species that will perform on the site. Many species can be used on many sites, but some sites are better suited for some species and will not grow others well. For example jack pine or red pine do well on sandy light soils, they will tolerate somewhat heavier soils, but will not tolerate a wet black spruce – tamarack site. Some species are very adaptive and cover a wide range of sites and soil conditions. Others are more exacting in their requirements.
Where is your site on the plant hardiness zone chart? One cannot expect a Southern species to survive in the far North. Likewise it’s best to match the hardiness zone that you are planting in with the seed source of the species that you wish to grow. Many species have evolved over time, following the glaciers back as they receded. The most hardy seed sources are in the Northern part of the species natural range and the less hardy are in the Southern part of their range. Some species are affected by minute changes in hardiness zones, and cannot tolerate being moved out of their natural ranges very well. Other, such as river birch, have been moved great distances out of their natural zones with very good success. See the USDA Hardiness Zone Map.
Soil moisture and precipitation requirements for trees vary greatly from species to species. Some species are well adapted to dry sites and can perform on them well, even with low rain fall. Others require good moisture levels and reliable rainfall. If your site is dry, don’t expect to see good survival or growth from species requiring readily available water.
Check the type of soils and if possible the pH (acidy – alkalinity). Many of the conifers prefer growing at a pH of 5.0 to 5.5 but will tolerate a wider range. However, many conifers do not grow at high pH above 7.0. Trees growing at lower or especially higher pH than they should may exhibit nutritional symptoms. The availability of various minerals and elements to the plants are affected by the soil pH. Some trees are not able to extract these minerals and elements in soils that have pH levels out of the range for that species. Sometimes this might by overcome with fertilizer correction, such as in the case of growing Christmas trees. Or in some cases where trees are growing out of their normal range, the organic levels in the soil are high enough to buffer the ph at the surface of the roots. (see fig. 1)
This all sounds complicated, but the best indicator is looking around and seeing what is growing on your site and surrounding similar sites. If you have nice red pine growing in the area similar to your site, it probably will do well on your site.
For more information on species and their requirements one can consult various forestry books and tree books.
When procuring planting stock select nurseries who can supply the seed source and the species that you need. The best policy when concerned with seed source is to ask what is available, rather than requesting specific sources. Some less reputable suppliers may switch a less than desirable seed source to meet your order so they can have a sale. The improper seed source may not show until after the plantation is established, and the species is not performing as expected for your site.
Improved seedlings developed through good tree improvement programs are available for some species in limited numbers and in the future will become more available. The advantage of using improved seed sources might include better growth rate and form, disease resistance, insect resistance, being less susceptible to late or early frost damage, and better foliage color and structure (for Christmas trees). Tree improvement programs take years to produce improved seedlings. Selecting and testing trees in a tree improvement program takes years or even decades. Improved seed sources are not the “silver bullet” in developing the “super tree” that out grows all and is resistant to all diseases, insects and adverse weather conditions. However, improved seed sources are the next best thing to this goal. Tree improvement programs, due to the fact that they take long years to develop improvements (some which may appear to be only minimal), are often running on shoe string budgets and moving ahead only under severely financial limiting conditions. As Woodland owners, we should encourage and support active and dynamic tree improvement programs to get improved planting stock in the future and in our children’s future.
3. What type of site preparation is needed to insure better survival and growth? Site preparation gives the planted seedling the improved micro site for its growth and survival. Some sites might not need site preparation, while others may require it as the only way to get a plantation established. Site preparation reduces or controls the competition from other vegetation that can over top, out compete and smother out your planted seedling.
On sites where site preparation is not necessary, there would be little competition from existing vegetation. These include old poor pasture land with low stocking of grass and weeds (run out land, whole tree logging operations shortly after they are completed and burned over areas from wild fires.
Mechanical site preparation is used in various forms. Spot scarification (Scarification=soil wounding). Loosening the top soil of open areas, or breaking up the forest floor) disturbs the site only around the area that the seedling is to be planted. Row scarification prepared strips of disturbed soil. Broadcast scarification would treat the whole site. Scarification may be conducted with some very specialized equipment as well as simply using farm tools or the tools at hand. Many a tree has been planted using a single or double bottom farm plow. A simple hoe or shovel has been used to scalp a spot in which the seedling is planted. Your site, the types of soils and the size of your operation will help determine what if any mechanical site preparation is necessary.
Mechanical site preparation can be costly, and over doing it does not insure that your plantation is going to do even better. On some soils mechanical site preparation may produces results that can be detrimental to your seedling survival. These include promoting better conditions for frost heaving of the seedling on frost susceptible soils, growing the seedlings on poorly drained soils and radically changing the pH of the soil on the surface by pulling up subsoil that has a high pH. In some operations on some soils, soil compaction can result from mechanical site preparation.
Fire is another means of site preparation. Control burning a site can reduce the brush and make it more accessible. It also releases some minerals so the seedlings can more readily use them. Usually fire alone will not wipe out competition from vegetation. It only sets the competition back, allowing the seedlings to get started. Post planting releases, usually using herbicides, are smothering them.
Herbicides are often used in chemical site preparation. They may be applied as spots, strips or broadcast, producing dead areas in which the seedlings are planted. Herbicides can be the more effective and economical form of site preparation for both the little and large programs.
Tree mats or mulches are also a form of site preparation. They can be quite costly, but often require only the one time treatment to get the seedling established and the site occupied. These include tree mats made of plastic, organic mulches, cardboard and newspapers. For small plantations this may be a good way to get trees established. The labor requirements are usually much higher than other site preparation methods.
4. What type of planting stock is going to be used? First, what types of planting stock are normally available? The most common types are bare root and containerized planting stock.
Bare root seedlings, are produced directly from seed sown in seed beds and lifted one or more years after sowing. The number of years in the seed bed is indicated by the first number in the bare root code i.e. 1 – 0, 2 – 0. Seedlings are lifter from the seed beds in the late fall or early spring, brought into the packing building and either stored under refrigeration for spring planting or shipped directly to the planting site. The seedlings may be “bed run” or graded. Bed run, means that essentially all the seedlings lifted are shipped. Grading will classify the seedlings into grades by size and usually all the poor quality seedlings are culled out. Usually graded seedlings are also root pruned and sometimes treated with moisture retaining jells. The graded, root pruned seedlings are preferred when purchasing bare root seedlings, as they will give better results in the field.
Transplants are seedlings that have been lifted from the seed bed, and transplanted into a bed at even spacing. Under good nursery practices the seedlings are graded and culled prior to transplanting, but this is not always the case. Some nurseries sell the seedlings that meet a good grade and use the lower grades to transplant. The transplants are coded as to the number of years in the seed bed (the first number) and the number of years in the transplant bed (the second number). A 2 – 2 transplant would mean that the seedling was grown 2 years in a seed bed and then lifted and transplanted and brown for two more years in a transplant bed before it is harvested. Various types of transplant stock may be available, the more common being 2 – 1, 2 – 2, 1 – 1, 3 – 1, 3 – 2 and 3 – 3. Sometimes, for sites needing exceptionally large specialized transplants, stock may be lifted and transplanted to a wider spacing for a second time, i.e.: 2 – 2 -2.
Transplants are usually larger and have a better developed root system than seedlings. When lifted they are usually graded. Root pruned and packaged for shipping or refrigerated for spring planting.
A different form of transplant is one that starts from a plug grown seedling produced in a container. These plugs are transplanted for one or more years before lifting, grading, root pruning and packing. They are coded as to the number of flushes as a plug and the number of years in the transplant bed. P-w stock has been grown one flush in the container and one year in a transplant bed. A P2-2 is a two flushed plug that has been transplanted for 2 years in a bed before harvesting. Plug transplants are becoming more popular as they are more efficient in utilizing seed and produce a well balanced uniform crop.
Containerized tree seedlings are started in container, usually under greenhouse conditions, grown through 1 or more flushes before they are shipped to the field. They may be shipped in the container to the field or extracted as a plug and shipped. Some advantages of containerized seedlings include:
- Planting stock can be planted from essentially frost out to early fall, a much larger window that bare root stock. This is due to the fact that the root system is not disturbed, as they have their own soil plug protecting the fine roots.
- Seedlings can be held in the containers for longer periods allowing planting when convenient and when conditions are best for the customer and for planting. All that is required is to keep the seedlings moist, which can easily be done with a lawn sprinkler and placing them in a shaded protected are.
- Planting shock is minimal when trees are removed from the container and planted.
- The container offers an easy means of handling seedlings without having the worry about keeping the roots moist and trees from drying out.
- Seedlings at all stages of growth may be shipped and planted from the container (dormant, hardened off and actively growing).
- The system is nearly fool proof, and well buffered for poor handling. There essentially is very little chance for root damage and problems such a J- rooting, or splitting roots at the root at the crown which can readily occur when handling bare root seedlings and transplants.
- Containerized tree seedlings can be planted using various conventional planting tools, such as planting bars, hoe dads, shovel, and mechanical machine planters. There are also special planting tools, such as dibbles and planting tubes, which are designed for planting containerized seedlings fast and efficiently.
- Generally there is less planting fatigue with containerized stock, as they go into the ground quickly and easily. Planting rates are usually much higher than planting with bare root stock.
- Survival of containerized planting stock runs 90 percent or better, as bare root stock may run 50 to 70 percent on the average.
- Seed sources and species identification are easily maintained using containerized seedlings, as the seedling does not get removed from its container until planting and the container can easily be labeled to keep sources and species information available right to the planting site.
Containerized seedlings may be extracted and shipped loose or jelly rolled to the field with very good success. We prefer, especially for small operations to have the seedlings shipped in the container. The containers add protection and reduce the chance for losses in shipping.
5. What season are the trees going to be planted? Normally bare root seedlings and transplants are planted in the early spring. Some late fall planting of bare root stock is successfully done in some parts of the country. In regions of the country that do not have their ground freeze, winter planting is often the preferred planting time. Containerized tree seedlings can be planted almost any time that the soil can be worked with very good survival and growth.
Bare root seedlings should be planted shortly after receiving them. They can, in some cases, be held for short periods of time in cold storage. Under delayed conditions, the bare root planting stock may be “healed in” by digging a trench in moist soil and laying the bundles of seedlings in the trench with the tops sticking out. Then back fill the soil up to the root collar and gently pack the soil. The tops may b e sheltered from direct sun by covering with brush or shading with burlap. They should b watered as needed. This is a short term method of holding bare root planting stock. Bare root planting stock should be planted before buds start to break and before much root growth has started. Survival and establishment can be drastically reduced when planted later.
6. What planting method is going to be used? Hand planting and machine planting are the two basic methods of planting. Most trees are hand planted. Planting may be done by one person, or teams of two (one person makes the hole with the planting tool and the second plants the seedling in the hole).
Steps in Hand Planting Bare Root Stock
- Trees to be planted should never be allowed to have their roots dry out. Wind and sunshine on bare seedling roots can kill or seriously injure the vitality in a minute. Stronger and older transplant trees are tougher but drying of the roots still injure the tree. Keep the seedlings in a bucket with a slurry of water and peat moss or water and soil covering the roots. The seedlings also can be packed in moist peat moss. Only remove one seedling at a time at the time of planting. Do not hold a hand full of seedlings as you plant. Drying can be reduced by dipping the bare root stock in water holding jells.
- Keep stock out of the direct sunlight and wind. Keep bundles of trees under reflective tarps or in deep shade.
- Dig holes deep enough and large enough so roots are not crowded or twisted into a cramped wad or ball. Do not dig holes more than a few ahead of planting. Keep one side of the hole straight so the tree placed against the straight side will stand up straight after planting and packing in. Close the hole completely; do not allow any air pockets. Plant seedlings so that the soil line is up to ½ inches above the root collar. Planting too deep or too shallow will greatly reduce survival.
- If the roots are too big to get into the hole easily, root pruning is in order. If the crown roots are spreading and brittle, they should be shovel or auger planted to avoid splitting the crown when closing the hole.
- Back fill holes with the dirt removed. Never place sticks, leaves, letter or grass in the hole. Push dirt around roots when digging a hole or auguring in trees. Firm up soil around the tree using hands and/or feet, being careful not damage the seedling.
- Do not J-root seedlings. Keep roots going down and spread out as much as possible. J-rooting and having roots above ground will reduce survival and initial growth. It is one of the leading causes of planting check.
- If the planting hole fills with water it is obvious that it is a wet site, plant on a higher site. Or planting on wet sites can be improved through mounding, (digging up a clump of dirt and tipping it over beside the hole and planting the tree in the clump and packing it in firmly). Mounding sometimes is done before planting as a site preparation technique.
- Avoid planting on very shallow soils to rock or to hard pan. Planting holes should be made the full depth of the tool.
See figure on planting depth and planting with planting bar and mattock:
For planting bare root stock with planting machines, one should follow the above guidelines. Don’t plant too deep, or J-root. Make sure the seedlings are well planted. Often it is wise to have a person following the machine and check the tightness of the planting by gently pulling on the seedlings. If it moves up, then the person either firms it up or replants it with a shovel.
Containerized stock is easier to plant, and can be done with the above tools as well as machines. As with bare root planting all stock should be kept moist and planted to the correct depth. The root plug should be firmed in with hands and/or feet, dislodging some of the native soil to cover the top of the plug. If you leave the top of the plug exposed or above ground level. The peat based soil can act as a wick and dry the seedling out. When t he peat plug is covered with a thin layer of native soil, it acts as a sponge and water reserve for the seedlings.
Planting dibbles work well when planting on most soils. The planting dibble is pushed into the ground to its full depth. The containerized seedling plug of soil is placed in the hole deeper than the surrounding native soil and firmed in. We do not recommend using planting dibbles on heavy clay soils, as the dibble tends to form a “clay pot” which is DIFFICULT FOR THE ROOTS TO EGRESS FROM. On heavy soils a planting bar, hoe dad, or shovel works well as they tend to fracture the clay, making places for the roots to grow into.
The tube planters for containers work well, as the planter does not have to bend over to place the seedling in the ground. However most of these tools work best on very light soils, such as Jack Pine sands. They do not work well in heavy or rocky soils.
NOTE: WHENEVER FIRMING IN THE SEEDLINGS BE CAREFUL NOT TO DAMAGE SEEDLINGS BY BARKING IT. FIRMING IN DOES NOT MEAN STEPPING ON THE SEEDLING! Many seedlings, both bare root and containerized, have been fatally wounded or badly damaged by girdling or debarking the stem when firming in.
7. Is protection from animal damage needed? Various animals will eat and/or pull up and destroy newly planted seedlings. Mice can cut them or girdle them, rabbits cut them off and deer browse on them and sometimes just pull them out of the ground. Good site preparation will often reduce the amount of animal damage, as their natural cover is reduced or destroyed and the natural food source is reduced or destroyed.
Various tree shelters have been developed and used to reduce animal and bird damage while accelerating the seedling growth. However most of these shelters work best on hardwoods. A new plastic mesh tube that is used to cover seedlings has been developed which is reported to work on both hardwoods and conifers. Over the years a number of seedlings have been protected with chicken wire and hardware cloth. All are quite expensive and require additional investments and time to install and maintain. They are effective.
Chemical repellents and deterrents have been developed recently which work quite well for deer. Some of these can be applied to the seedling prior to planting. We have offered as a service, spraying Tree Guard tm on containerized seedlings before shipping, so when the seedling is planted, the deer learn that the new plant on the block tastes bad.
Planting later in the spring, after “green up” also trends to reduce initial damage from animals, as there is much more food for the deer. However, damage may occur in the fall, winter and early spring when the deer and other animals are harder pressed for food. Fall and early winter applications of animal browse deterrents, such as Tree Guard, tends to reduce these losses. In some cases the deer population is so out of balance with the range, that they will nearly eat everything in sight, and deterrents have a lesser effect on controlling losses.
If you suspect high mice population, the planting site might be baited to reduce the populations. One way of testing is to place 10 mouse traps across the site, and if you catch more than one mouse a night for the first three nights you might have a problem. More than that there is a good chance you will have a problem. The best way of controlling mice and rabbits is to remove or control the natural cover and allow the predators to feed on them. Site preparation usually does this. Leaving perch poles for owls and hawks will help reduce populations of both mice and rabbits.
8. Special treatments that may increase survival and growth. We refer to these as plant health care products. Some of these include: Transplant fertilizer; root dips for water management; growth stimulants; and mycorrhizae inoculants.
We have seen increased survival and initial growth with all these products. They often make the difference in survival and establishment under extreme conditions, such as drought. And on extreme sites, such as mine land reclamation, run out farm fields, and highly disturbed sites such as new road cuts. In good years which have conditions good for tree establishment and growth, one may not see any differences between the treated seedlings and the untreated seedlings. In agriculture land the mycorrhizae have been proven very beneficial. Read up on these products, inquire about them and weigh them against your planting site and needs.