- THE FLORICULTURE VEGETATIVE CUTTING INDUSTRY 149
arrival; Stage 1 – Cutting arrival or harvest from in-house stock plants
and insertion into the substrate; Stage 2 – Callusing; Stage 3 – Root
development; and Stage 4 – Toning (Klopmeyer et al. 2003; Dole and
Hamrick 2006). Therefore, environmental and cultural conditions are
adjusted for each stage of propagation in order to promote rapid callus-
ing, rooting, and biomass accumulation with the expectation of having
uniform rooting and high-quality rooted cuttings (Currey et al. 2012).
A. Preparation for Cutting Arrival (Stage 0)
Strict sanitation protocols are employed during Stage 0 and set the
precedent for all other stages of propagation. Prior to the arrival of
unrooted cuttings, environmental controls are tested, coolers, benches,
trays, and propagation areas are prepared, cleaned, and sanitized. Root-
ing substrates are mixed, prepared, or purchased, and trays are filled
during Stage 0. The trays are then placed on the propagation bench or
floor and thoroughly moistened. Most herbaceous unrooted cuttings are
propagated in thin plastic trays or liner strips containing 18–105 cells. A
variety of lightweight substrates, including peat and perlite mixes, rock-
wool, rigid foams (e.g., Oasis®Wedge or Root Cube®), and stabilized
media (e.g., EllepotsTM, Fertiss®) are used to root cuttings. The sub-
strate should be firm and dense enough to support the cutting upright
and without movement during rooting. It should also retain adequate
moisture to keep the cutting turgid, and provide drainage and oxygen
for rooting. In order to provide sufficient oxygen for rooting, the prop-
agation substrate must have 25–35% porosity. Substrates should never
be compacted as this reduces the supply of oxygen to the base of the
cutting and inhibits root development (Dole and Wilkins 2005).
Water quality is important for misting, fogging, and irrigation dur-
ing cutting propagation, since water impacts substrate pH and soluble
salts which can impact rooting and shoot growth. Additionally, plant
quality can be negatively impacted by salts dissolved in the irrigation
water which leave deposits and residues on plant tissues. Electrical
conductivity of water used for propagation should be<0.5 mS cm−^1 ,
and the water alkalinity should be<100 ppm bicarbonate. High soluble
salts will also contribute to biofilm accumulation in the irrigation lines,
which can block mist emitters (Fisher et al., 2009).
B. Cutting Arrival, Prioritization, and Handling of Species (Stage 1)
Upon arrival, boxes containing cuttings should be opened immediately,
inspected for turgor, quality (e.g., appropriate length, caliper, leaf num-
ber and size), proper labeling and quantity, noticeable signs of damage,