Transplanting Standard Operating Procedure

Transplanting Standard Operating Procedure#

Planting Media#

  • Measurement: Nursery planting media is measured in bushels (bu).

    • At the nursery, the bushel is both a measurement (35.239 liters) and the name of the wooden box used to measure 1 bushel.

  • Fertilizer Application:

    • Slow-release fertilizer rates are calculated per bushel.

    • Mixing slow-release fertilizer or any other amendment is performed by dumping a measured volume of planting media onto the potting table and mixing thoroughly.

  • Pre-Moistening: Pre-moisten planting media before use.

  • Types of Growing Media:

    • Standard

    • Alpine

    • Bulb

Transplanting Types#

  • Pricking-Out:

    • Refers to transferring a seedling from a communal seed pot to an individual growing container.

    • Goal: Minimize root damage.

  • Repotting:

    • Refers to transferring a single plant into a new, typically larger, growing container.

    • Goal: Discourage root spiraling during repotting.

  • Division:

    • Involves breaking up the root mass of a single container to recover two or more individuals for repotting.

    • Applicable for dividing genets from clump-forming species or genetically distinct individuals sharing a crowded growing container.

    • Note: Root damage is expected during division.

Pot Sizing#

  • General Size Rule:

    • Seed Pot: 4” square

    • Cuttings: 2 ¼” square

    • Perennial Forbs & Grasses:

      • 2 3/8” x 3 ¾” band pot → 2 7/8” x 5 ½” → 3 5/8” x 6”

    • Alpine Ferns:

      • 2 3/8” x 3 ¾” band pot → 3 9/16” x 4 ½”

    • Tree & Shrub:

      • 2 3/8” x 5” band pot → 2 7/8” x 9” → 4” x 10” → 5” x 12”

Pre-Filling Pots#

  • It can be advantageous to pre-fill an entire tray of pots with planting media before pricking-out.

    • Important: Do not leave excess media in the bottom of the tray.

  • Process:

    1. Load the tray with pots (loading tray).

    2. Scoop moistened, fertilized media into pots until all pots are filled to just above the top.

    3. Use a straight edge (or hand) to remove excess media.

    4. Tap the tray against a hard surface 3-4 times to compact the potting media.

    5. Top up any pots that have compacted more than others and re-tap.

    6. Transfer pre-loaded pots into a new, clean tray (cultivation tray).

    7. Recover excess planting media from the loading tray.

  • Note: Pre-filling the pots is not helpful in repotting and of limited use in division (dependent on the size of the root zone of the plants involved).

Pricking-Out#

  • Objective: Minimize damage to the growing root (radicle) during transfer from seed pot to cultivation container.

  • Process:

    1. Work with seed sowing media that is just slightly moistened.

      • Enough moisture to keep the shape of the potting media ball if the pot is upturned, but not so wet that the media ball doesn’t easily break apart.

    2. Grasp the pot with one hand on the bottom and the other on top, with fingers splayed open.

    3. Tilt the seed pot upside down and catch the media ball in the splayed-finger hand, supporting the media ball without crushing the seedlings.

    4. Place the unpotted ball onto a clean, hard surface.

      • Depending on the moisture level, the media ball will either remain intact or fall into an unstructured pile.

    5. Tease out healthy seedlings by allowing the media to ‘fall away’. Avoid shearing or mechanical damage to the root.

    6. Hold seedlings by the cotyledons or first true leaves, or develop a light touch to manipulate the seedling by grasping the stem just below the cotyledons.

    7. Use a dibber/dibbler/pencil to make a hole in the planting media, typically in the center of the pot (exceptions for multiple plants in a pot or planting a parasite/host pair).

    8. The planting hole should be slightly deeper than the length of the root and wide enough so that the root doesn’t catch on the side.

    9. Hold the hypocotyl level with the soil surface and allow the root to drop into the hole. Use a tool to tease the root into the hole if required.

    10. Collapse the sides of the planting hole by inserting the dibber repeatedly into the surrounding media, taking care not to touch the roots directly. Keep the hypocotyl level with the soil surface.

    11. Top up pots with low media levels and exposed roots.

    12. Settle the plant into the pot by gently tapping the pot against a hard surface and/or light probing with a dibber around the seedling to collapse air pockets.

    13. Place on the floor grate in the header house and water until saturation.

    14. Post-watering, use a dibber tool to straighten transplants if necessary.

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