3What 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).
4How 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.
6Advantages 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.
7Advantages 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.
8Advantages of PIP Reduced water usage. Eliminates blow over. 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 top-dressed fertilizers.
9Advantages 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.
10Advantages of PIP Prevents root loss associated with field harvesting. Reduced shipping costs compared to field grown B&B plants.
11Disadvantages 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.
12Disadvantages of PIPRoot escape into the socket pot and surrounding soil.Roots may grow through the drainage holes of both the insert and socket pots.
13Solving Root EscapeInsert PotSpin Out treated Socket PotApply 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.
14Solving 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 potThe 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 PotSocket PotBioBarrier
15Solving Root EscapeSpin Out treated fabric linerInsert PotSocket PotUse Spin Out-treated fabric bags such as Tex-R Agroliners inside the insert pot.
16Disadvantages of PIPInsert 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 PotSocket Pot
17Growing MediaPine bark is the main component with particles in the 3/8 – 1/2 inch size.A common media consists of:4 parts pine bark1 part peat mossNo sand.
18Irrigation Pond or well. Filtered. Drip irrigation using: Micro-sprinklersSpray stakesCoverage 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.
191 inch black poly lateral irrigation line Irrigation SchematicSpaghetti tubeSpray stake or micro-sprinklerInsert potSocket pot1 inch black poly lateral irrigation line