Standard Operating Procedure (SOP) for Horticulture

PURPOSE & SCOPE:
Planting trees is an easy and effective way to beautify our property, provide shade in summer and wind protection in winter.  Tree is such a visible part of the landscape care must be taken to ensure proper growth conditions are maintained.  A tree is far more difficult and expensive to replace, once mature in the landscape, than most shrubs. 
RESPONSIBILITIES:

Head of Administration is responsible for implementation of this SOP

CHOOSING A TREE:

The first step in tree selection is to determine the type of tree appropriate for your property and your needs.  Climate and soil play big roles. make sure that the tree species you are considering can flourish in your local climate and soil conditions. 

And don’t forget some of these other important factors:

    Matching tree to site is a key part of the tree selection process.

Trees can play an important role in climate control. Deciduous trees planted on the south, west and east perimeters of a lot will provide shade during the summer while allowing scarce sunlight through in the winter when leaves have fallen. Evergreens, on the other hand, planted on the north and west sides of a property, can reduce winter heating costs by serving as windbreaks.

TYPES OF TREES

Balled and Burlapped

Container- Grown

Bare Root

Trees purchased from wholesale and retail nurseries and garden supply stores generally come in one of three forms:

Balled and Burlapped
The roots of the tree and the ball of soil containing the roots are bound in burlap.

Container-Grown
The plant is sold in the container in which it was grown.

Bare-Rooted
The plant is sold with the roots exposed.  Not very common with trees.

WHEN TO PLANT TREES

Climate plays a deciding role when determining the appropriate planting time.  Newly planted trees do best when exposed to moderate temperature and rainfall and they need time to root and acclimatize before the onset of intense heat and dryness of summer or the freezing temperatures of winter. Spring and early fall, therefore, are generally the best planting seasons (depending on location) with spring preferred over fall in the more northerly latitudes. 

HOW TO PLANT A TREE

While planting each of these different types of trees differs in the details, all trees eventually end up in a hole. But not any old hole will do.

The most common mistake when planting a tree is a digging hole, which is both too deep and too narrow.  Too deep and the roots don’t have access to sufficient oxygen to ensure proper growth.  Too narrow and the root structure can’t expand sufficiently to nourish and properly anchor the tree.
As a general rule, trees should be transplanted no deeper than the soil in which they were originally grown.  The width of the hole should be at least 3 times the diameter of the root ball or container or the spread of the roots in the case of bare root trees.  This will provide the tree with enough worked earth for its root structure to establish itself.
When digging in poorly drained clay soil, it is important to avoid ‘glazing’.  Glazing occurs when the sides and bottom of a hole become smoothed forming a barrier, through which water has difficulty passing.  To break up the glaze, use a fork to work the bottom and drag the points along the sides of the completed hole. Also, raising the centre bottom of the hole slightly higher than the surrounding area.  This allows water to disperse, reducing the possibility of water pooling in the planting zone.
PLANTING BALLED AND BURLAPPED TREES.

Balled and burlapped (B & B) trees, although best planted as soon as possible, can be stored for some time after purchase as long as the ball is kept moist and the tree stored in a shady area.  B & B trees should always be lifted by the ball, never by the trunk.  The burlap surrounding the ball of earth and roots should either be cut away completely (mandatory, in the case of synthetic or plastic burlap) or at least pulled back from the top third of the ball (in the case of natural burlap).  Any string or twine should also be removed.  Backfill soil (combinations of peat moss, composted manure, topsoil, etc.) is then placed in the hole surrounding the tree just to the height of the ball or slightly lower to allow for some settling.  Be careful not to compress the back fill soil as this may prevent water from reaching the roots and the roots from expanding beyond the ball.

PLANTING CONTAINER TREES.
Container trees (though subject to greater heat and drying conditions than B and B) can also be stored for a brief period of time after purchase as long as the soil in the container is kept moist and the tree stored in a shady spot.  The procedure for planting container trees is similar to that for B & B trees.  In the case of metal or plastic containers, remove the container completely.  In the case of fibre containers, tear the sides away.
Once carefully removed from the container, check the roots.  If they are tightly compressed or ‘potbound’, use your fingers or a blunt instrument (to minimize root tearing) to carefully tease the fine roots away from the tight mass and then spread the roots prior to planting.  In the case of extremely woody compacted roots, it may be necessary to use a spade to open up the bottom half of the root system.  The root system is then pulled apart or ‘butterflied’ prior to planting.  Loosening the root structure in this way is extremely important in the case of container plants.  Failure to do so may result in the roots ‘girdling’ and killing the tree. At the very least, the roots will have difficulty expanding beyond the dimensions of the original container.  To further assist this, lightly break up even the soil outside the planting zone.  This allows roots that quickly move out of the planting zone to be more resilient as they anchor into existing surrounding soil conditions.
Once the tree is seated in the hole, the original soil is then back-filled into the hole to the soil level of the container.  Again, remember not to overly compress the back-filled soil especially by tramping it with your feet.  Compress gently using your hands instead.

PLANTING BARE-ROOTED TREES.

Planting bare-rooted trees is a little different as there is no soil surrounding the roots.  Most importantly, the time between purchase and planting is a more critical issue.  Plant as soon as possible.  When purchasing bare-rooted trees, inspect the roots to ensure that they are moist and have numerous lengths of fine root hairs (healthy).  Care should be taken to ensure that the roots are kept moist in the period between purchase and planting.  Prune broken or damaged roots but save as much of the root structure as you can.

To plant, first build a cone of earth in the centre of the hole around which to splay the roots.  Make sure that when properly seated on this cone the tree is planted so that the ‘trunk flare’ is clearly visible and the ‘crown’, where the roots and top meet, is about two inches above the soil level.  This is to allow for natural settling.

WATER, MULCH AND FERTILIZER

Watering

Newly planted trees should be watered at the time of planting. In addition, during the first growing season, they should be watered at least once a week in the absence of rain, more often during the height of the summer. However, care should be taken not to overwater as this may result in oxygen deprivation.

If you are uncertain as to whether a tree needs watering, dig down 6-8 inches at the edge of the planting hole. If the soil at that depth feels powdery or crumbly, the tree needs water. Adequately moistened soil should form a ball when squeezed.

Regular deep soakings are better than frequent light wettings. Moisture should reach a depth of 12 to 18 inches below the soil surface to encourage ideal root growth.

Mulching

To conserve moisture and promote water and air penetration, the back filled soil surrounding newly-planted trees can be covered with mulch consisting of material such as bark, wood chips or pine needles (although the acidity associated with pine needles is not suited for many plants). Mulch depth should be between 3 to 4 inches. Do not, under any circumstances, cover the area surrounding the tree with plastic sheeting since air and water movement are prevented. Porous landscape fabric can be used since it freely allows water and air penetration.

Fertilizer

Since all soils have a history, it can be beneficial to get soil analyzed properly for macronutrients such as Nitrogen (N), Phosphorus (P) and Potassium (K), micronutrients, pH, soil type, and drainage. Although many trees survive without fertilizer at time of planting, the majority of plants suffer root loss and stress associated with movement between ideal nursery grown conditions and the final planting.  

Staking and Guy-Wiring

Young trees should be able to support their own weight, but when they are transplanted, they often need time to reestablish themselves.  Also, many nurseries plant their trees very close together to maximize use of space and stake them to promote height growth at the expense of trunk strength.  When shopping for trees, look for trees with branches all along the trunk - not just at the top.

Once a tree is planted, it will concentrate its energy on standing upright.  If it is unable to do so, try thinning out the upper branches to reduce wind resistance.  If that is not enough and you find you have to stake a tree, remember the following"

1. Only stake the tree long enough for it to be able stand on its own. 

2.  Stakes should not be too tight - there should be room for the tree to sway in the wind.

3. Stakes should not be too loose - the tree should not rub against the stakes.

4. Stakes should be buried at least 1.5 feet underground to provide ample support.

WRAPPING AND PRUNING

Wrapping

Wrapping refers to the technique of winding a crepe-type paper around the barks of trees. Generally speaking, you only need to consider doing this in the northern United States and Canada to prevent the ‘sun-scalding’ of thin-barked trees like soft maples and crabapples during the first one or two winters after planting. Commercial tree-wrap is sold at nurseries and in garden-supply stores. To wrap a tree, start at the bottom and wind the paper around the tree to the level of the second branch. Fasten the paper at the top with a tack. Don’t forget to remove the wrapping each spring to prevent moisture buildup, disease and insect infestation.

Pruning

Use restraint when pruning your newly-planted trees. Prune only to remove damaged or broken branches. Do not prune the top of the tree as this may alter the structure of the tree excessively (check species requirements) and may hamper carbohydrate production.  Do not paint the cuts with compounds (e.g. Latex) that prevent air from accessing the wound, thereby slowing the healing process.

Transplanting Trees

There is always danger in moving plant material from one location to another.  Root material is sacrificed, and depending on the previous state of the plant, this can be a severe stress.   If necessary, it is possible to transplant trees from one area of your property to another. The key lies in ensuring that the tree to be transplanted has a good healthy root ball and that the tree and ball together are not unmanageably heavy.

•  Start by tying the branches together loosely.

•  Then dig a two-foot deep trench around the tree at least one foot larger than the size of the root ball (or as much intact viable root material as practical). Once the trench is dug, undercut around the shrub. Carefully prune the roots extending from the ball as you dig down.

•  When the ball is partially exposed, begin to wrap the ball in burlap starting from the base of the tree down using twine to secure the wrapping. Keep digging until the ball is undercut and sitting on a soil pedestal.

•  Then carefully tilt the tree and ball and finish wrapping and securing the burlap underneath.

•  Then carefully tilt the tree and ball and finish wrapping and securing the burlap underneath.