Techniques of Propagation by Cutting

• cutting propagation: a portion of the stem, root, or leaf is cut from the parent or stock plant and indued to form roots and shoots
• Plants made from cutting propagation are clones, which are identical to the parent plant
• Cutting propagation is the most important means of propagating ornamental shrubs
• Cutting propagation is more costly than seed propagation because:

  • requires the use of protected culture
  • bottom heated rooting system
  • intermittent mist system and/or fog systems
• Propagules (cuttings) can be collected from stem, root, or leaves
• classification based on part of the plant from which they are collected:

  • stem
  • leaf
  • leaf-bud
  • root
• stem cuttings: segments of shoots containing lateral or terminal buds are obtained, and under the proper conditions adventitious roots will develop and produce independent plant
• important factors for the satisfactory rooting:

  • type of wood
  • stage of growth
  • time of year
• types of stem cuttings:

  • hardwood
  • semi-hardwood
  • softwood
  • herbaceous
• hardwood cuttings: matured, lignified wood after the leaves have abscised
• For hardwood cuttings, include at least 2 nodes. Cut just below a node and 1.5-2.5cm above a top node
• hardwood cuttings are prepared during dormant season (late fall, winter, or early spring)
• hardwood cutting advantages:

  • least expensive and easiest
  • not readily perishable, easy to ship
• straight cut: most commonly used; use of a slanted cut to distinguish proximal and distal end
• heel cut: a small section of older wood is included at the base
• mallet cut: an entire section of older stem wood is included
• Heel and mallet cuttings are used for difficult to root plants
• 2,500-5,000 mg/L IBA quick dip for hardwood cuttings
• 3 systems of hardwood cutting:

  • direct fall planting
  • spring planting
  • initiation of rooting with bottom heat
• direct fall planting: allowed to grow one season, then harvested; used for slower-rooting species
• spring planting: collected in late-fall/winter; cold, moist storage
• initiation of rooting with bottom heat: collected in fall or winter, treat basal ends with IBA 2,500-5,000 mg/L; proximal ends maintained at 65-70F, shoots exposed to cool temperature; used for difficult to root species
• preparing hardwood cuttings of deciduous Rosa multiflora rootstock:

  1. band saw used to cut 15cm cuttings from rose canes
  2. "de-eyeing" all lower axillary buds to prevent suckering of rootstock
  3. de-eyed cuttings in bundles of 50
  4. dormant rose budwood and thornless, de-eyed rootstock prior to sticking
  5. raised, shaped beds, propagated with Rosa multiflora hardwood cuttings
  6. rooted, leafed-out cutting removed in April
• Hardwood cuttings are slow rooting
• Hardwood cuttings should be harvested in late fall to late winter
• Hardwood cuttings require high humidity and high light intensity
• Hardwood cuttings usually require bottom heat
• Hardwood cuttings often use basal wounding
• semi-hardwood cuttings: partially mature wood from recent growth; may or may not have visible periderm
• Semi-hardwood cuttings are harvested in late spring to late-summer or early fall
• typical length of semi-hardwood cutting: 3-6 inches
• Semi-hardwood cuttings require 1,000-3,000 mg/L IBA/NAA
• Trimming semi-hardwood foliage is done to reduce transpirational water loss and facilitate more cuttings per square foot
• Magnolia cuttings are wounded at the base prior to auxin application and sticking
• softwood cuttings: soft, succulent new growth in woody species; very recently matured; actively growing, but cannot be too tender
• softwood cuttings are harvested in spring or early summer
• softwood cuttings generally root fast
• softwood cuttings are 3-5 inches long
• softwood cuttings require 500-1,250 mg/L IBA/NAA
• softwood leaves on the lower portion are removed and larger leaves are trimmed