Pot in Pot Nursery Production
Commercial Plant Production
A Pot in Pot Nursery
What is pot in pot (PIP) production?
 A method of producing of shade trees,
intermediates, and shrubs using a combination
of field growing and container production
techniques.
 PIP acres in production has been increasing
steadily since the 1990’s.
 More plants are grown per acre using PIP than
field production (Physical and Economic
Requirements for Pot-in-pot Nursery Production;
McNiel, et al).
How does PIP production work?
Two different pots are used:
Socket pot: set into the ground so that 3-6
inches of the container lip is above grade.
Insert pot: this pot contains the growing medium
and plant. The insert pot “plugs” into the socket
pot.
PIP schematic diagram
Advantages of PIP
Insulates the roots from temperature
fluctuations.
In traditional, above ground, container
production it is a well documented fact that high
media temperatures kill roots. Media
temperatures can exceed 140º F. in the sun.
Advantages of PIP
Allows for in-place overwintering.
In traditional container production plants are
typically consolidated into quonset houses that
are covered with white poly.
Decreases production time from liner to
finished product.
Water and fertilizer inputs are controlled by the
grower.
Advantages of PIP
Reduced water usage.
Most PIP nurseries are drip irrigated.
Eliminates blow over.
Traditional container grown plants with large
canopies tend to blow over.
Blow over results in a loss of media and topdressed fertilizers.
Advantages of PIP
Year-round harvesting.
Reduced harvesting labor compared to
field production.
Field grown plants are generally harvested
when they are dormant.
Digging plants out of the field is labor intensive.
Advantages of PIP
Prevents root loss associated with field
harvesting.
Reduced shipping costs compared to field
grown B&B plants.
Disadvantages of PIP
Higher initial cost of installation.
Up front expenses include grading, tiling,
purchasing socket and insert pots, irrigation
system installation, and liners.
Drainage concerns.
PIP is recommended on sandy soils. It can be
accomplished on heavier soils providing they
are properly drained.
Without proper drainage, the socket pots may
fill up with water.
Disadvantages of PIP
Root escape into the socket pot and
surrounding soil.
Roots may grow through the drainage holes of
both the insert and socket pots.
Solving Root Escape
 Apply a copper
compound (Spin Out)
to the bottom one-third
or one-half of the
socket pot.
 The copper compound
will kill the root tips
when they reach it.
Insert Pot
Spin Out treated
Socket Pot
Solving Root Escape
 Use BioBarrier.
 BioBarrier is a cloth-like
material impregnated with
Treflan herbicide.
 A piece is cut to fit inside the
bottom of the socket pot
 The Biobarrier releases a
gas that will prune the roots
of the plant before they can
grow out the drainage holes
of the insert pot.
 Requires a good seal
between pots.
Insert Pot
Socket Pot
BioBarrier
Solving Root Escape
 Use Spin Out-treated
fabric bags such as
Tex-R Agroliners
inside the insert pot.
Spin Out
treated fabric
liner
Insert Pot
Socket Pot
Disadvantages of PIP
 Insert and socket pots
may stick together
making removal difficult.
 The bottom of the insert
pot may sag, creating
an uneven base.
 The plants may be
exposed to the drying
effects of winter’s winds.
 Limited flexibility in
spacing plants.
Insert Pot
Socket Pot
Growing Media
Pine bark is the main component with
particles in the 3/8 – 1/2 inch size.
A common media consists of:
4 parts pine bark
1 part peat moss
No sand.
Irrigation
 Pond or well.
 Filtered.
 Drip irrigation using:
Micro-sprinklers
Spray stakes
 Coverage is important. The entire medium
surface must be wetted. This is especially true if
you top-dress fertilizers.
 Larger pots may require 2 or more nozzles.
Irrigation Schematic
Spaghetti
tube
Spray stake or
micro-sprinkler
Insert pot
Socket pot
1 inch black poly
lateral irrigation
line
Micro-sprinklers
Spray Stakes
The Nursery “Floor”
Bare soil.
Grass buffer strips.
Ground cover fabric.
Bare Soil “Floor”
Grass Buffer Strips
Ground Cover Fabric “Floor”
The End