Tree Planting Tips - Doing it Right the First Time
By Bob Tritten, district horticulture and marketing agent, southeast Michigan,
Michigan State University
With the coming of springtime, thoughts in fruit growers minds
are turning to the many jobs that need to be done.
Tree planting is one of these important tasks that many fruit growers take
for granted and don't spend enough time planning for. The focus of this
article will be on providing tips for setting out a new block of tree fruit
as well as planting replacement trees. The major focus of tree planting
should be doing it right the first time, and not thinking about replanting
trees that didn't live for one reason or another.
Care Before Planting
Proper care should be given to trees if they arrive before you are ready
to plant, as is usually the case at most farms. Trees should be kept as
cool as possible; a cooler is best. By keeping the trees as cool as possible,
you will delay bud break for a longer time.
Be certain to check the trees when they arrive and every few days thereafter
to be sure that the sawdust or other packing material around the roots is
not dried out. You want to keep enough moisture close to the tender root
systems to prevent desiccation. However excess moisture could also cause
rot organisms to begin to develop. I suppose it goes without saying, but
I need to remind growers that fruit trees placed in the cooler should not
have any apples stored in that same cooler. The cooler should be well ventilated
prior to placing trees into it.
When to Plant
Numerous studies have shown over the years that planting as early as possible
in the season is advisable. The key indicator to tell you when to plant
is your soil conditions, and particularly moisture levels.
Be sure that soil is dried out sufficiently that it will settle quickly
around the root system after planting. For the most part we talk about planting
when the soil is crumbly. This means that if you pick up a handful of worked
soil in your hand, squeeze it gently, and let it go, that it breaks apart
or is crumbly.
There is often a temptation to plant when the soil is too wet, and in some
case to even mud in the trees. This is a dangerous practice, as it gets
the trees off to a bad start immediately. Trees which are planted in soils
that are too wet will not take off as fast, and have a chance of developing
secondary problems.
The question that comes to me later in the spring is "when is it too
late to plant fruit trees?" Fruit trees should be planted before warm
weather. The cut-off date that I generally use for southeast Michigan is
early to mid May. Planting after that time will often subject trees to consistent
day time temperatures in the mid 60s and 70s, and the tree's leaf system
will break or begin to grow before the roots have established themselves
well. This could cause early desiccation of the tree and result in premature
tree loss.
Tree Planter, Auger or Hand Planting
The age old debate continue as to which is the best technique to plant fruit
trees, with the planter, an auger or hand planting. There are benefits and
drawbacks to each method.
A tree planter is generally the quickest way to plant, specially with high
density orchards. However, many times fruit growers have a tendency to want
to rush the planting process with the tree planter and plant early before
the soil is truly ready. Also it is much more difficult to regulate the
height of the graft union when planting with a tree planter. Inconsistent
graft union height will cause inconsistent growth for the entire life of
a block of fruit trees.
Another drawback of using a tree planter is that there have been times when
the soil does not close fully around the root systems, leaving an open slice
in the soil. At times you will find an area along the row where the root
systems have been exposed to air entering the soil down through the slice
left by the planter. Roots then dry out because they are exposed to air
and are killed.
Many people continue to plant trees with an auger. Augers work well particularly
for replanting trees. The downfall in using an auger comes when the soil
is wet. The edge of the hole can become greasy when it is dug. This greasy
soil condition will cause an impermeable layer to develop around the hole
in which the roots can not grow through. In many cases root systems of fruit
trees planted with an auger when soil conditions are too wet become rootbound
for several years. People with rocky soils also have difficulty planting
with an auger.
One additional challenge with an auger is that of trees settling after planting.
In many cases growers need to come back through their blocks of tree fruits
to be sure that the graft unions are a consistent height throughout the
entire planting. Most times trees need to be gently lifted out of the soil
to obtain a consistent graft union height.
Hand Planting
Hand planting fruit trees has been a practice that has gone by the wayside
at many farms. However, if the soil is worked well prior to planting, hand
planting can go very quickly and may be more economical than many people
believe.
When hand planting trees you have the best control over the entire process.
You can also eliminate much of the tree settling and graft union height
consistency when planting by hand.
Soaking Roots
Many growers soak the roots of their trees in water for a time before planting
with 24 hours being a common time.
This could include soaking trees in a pond, in 55-gallon drums or water
troughs. One word of caution about soaking trees in a pond, be certain that
you don't have unwanted critters, such as muskrats, that would find a meal
of tender young roots to be quite a delicacy in spring time.
Care on Planting Day
One additional problem that I see quite frequently is that growers don't
take good care of their trees between the time that they come from the storage
area to the time that they are planted.
In many cases I see boxes of the trees that are left open, or trees which
are piled for a few hours in the direct sun. Any exposure of the root systems
to the sun and/or wind will cause desiccation and may cause permanent damage
to the tree. Be certain that trees are in the shade while waiting to be
planted and that the root systems are not exposed to wind that will cause
desiccation.
The nursery that grew your trees has taken a great deal of care to be certain
that the root systems are not allowed to dry out. A little extra care given
to trees prior to planting will mean a greater chance of success.
Graft Union Height
Be certain that the height of the graft union is consistent throughout the
planting. This is one of the most important factors to consider when planting
fruit trees.
Generally speaking, the higher the graft union is out of the ground, the
more dwarfed a tree will be. For the most part I would like to see the graft
union about two inches above the ground level. However in some very high
density orchards, the graft union may be as much as six or eight inches
above ground level. The key factor is one of consistency. If all of the
graft unions are the same height above ground level, then your planting
will have a great chance of growing uniformly. If graft unions are close
to the soil surface, scion rooting may occur.
Placement of the graft union height is important enough that I recommend
growers walk their plantings two weeks after planting to adjust the height
of trees after the ground has settled a bit. Again, trees planted too low
can be gently lifted during these first few weeks.
Watering
Watering trees is another important consideration in getting a planting
off to a good start. I prefer that trees be watered immediately after planting.
The watering process helps to settle soil around the root system, and eliminates
air pocket which could cause injury and premature death to root systems.
Under Michigan conditions, most often we get rain within a week of planting.
This is typically sufficient to encourage soils to settle in around the
root systems and get trees off to a good start. However I have seen springs
where rainfall was too short, and where growers waited three to four weeks
before irrigating newly planted trees. This is much too long to wait and
in many cases injury or premature tree death had taken place in that time
period.
Staking
Staking at the time of planting is another key factor of success. Staking
helps to keep the tree stationary which will encourage more growth. Stakes
need to be in the ground as soon as the tree in planted.
A common question that is asked of me is what stakes seem to work the best
these days. I encourage growers to use the least expensive stakes and system
available to them to keep the tree stationary.
The system, which appears to be working well for fruit growers right now
is the use of a single-wire trellis system. This high wire is placed six
to eight feet above ground level and is used primarily to support the top
of the stake. Stakes used could include conduit, bamboo or a wooden pole.
Again pencil out the cost to determine which is the least expensive system.
Tree Training
Tree training is also an important consideration at planting time and could
be the topic for an entire book. Needless to say, spend a lot of time on
tree training at planting time. The type of training depends on tree density,
branch structure of trees and design of the block.
Conclusion
Planting fruit trees is an important part of the orcharding process, and
is key to getting the block of fruit off to a good start. Please take special
care to do a good job of planting, as it's the first step to a successful
conclusion many years down the road.