Four Star Culture Guide - 2019 - 81

DEUTZIA
ZONE HARDINESS 5 - 8
NUTRITION
pH: 5.6 - 6.2
EC: (2:1 extraction method) 0.6 - 0.9
Moderate fertilization is recommended. 150ppm - 200ppm N
TEMPERATURE for forcing from liners
Forcing/Growing on: 65 F Night - 72 F Day
Holding: 40 F Night - 50 F Day
Once plants reach a saleable size, they can be moved to a frost
protected open environment with good air movement. Crops
will slow down in the heat of the summer.
WATERING
Moderate to Moist: Water thoroughly without oversaturating.
Keep moist during root development. Keep watered adequately
during the rooting in stage - especially during hot months.
TIMING
28 Liner to True 1 Gallon: 8 - 10 weeks with one plug per
container. A typical planting date for spring forcing would be
Week 10 for finishing in Weeks 18 - 20. If full color at retail or
a larger size is desired, we recommend planting these in the
fall and doing additional bulking prior to dormancy. Planting
a 28 count liner into a 2 Gallon container and bulking in the
summer is a great way to finish a larger high-quality crop for the
following spring.
Quick Turn™ Liner to True 1 Gallon: 7 - 8 weeks with one
plug per container. A typical planting date for spring forcing
would be Week 10 for finishing in Week 18. Planting a Quick
Turn liner in Week 20 for finishing in Week 28 is also achievable.
Quick Turn Liner to 2 - 3 Gallon: Planting a Quick Turn liner
into a 2 - 3 Gallon container and bulking in the summer is also a
great way to finish a larger high-quality spring crop.
For growing and producing a crop in the same season, please
be aware that Deutzia flush and flower very quickly in the spring
and may reach their peak color 2 - 4 weeks before the crop is
fully rooted. For this reason, it's advised to grow Deutzia in their
final container and build the root system the previous season.

VERNALIZATION
Deutzia require vernalization for flowering. They will not put on
a full flower show without a cold treatment.
Hold Deutzia in the winter time in an area that will maintain the
root zone just above freezing.
PLANTING
Deutzia perform best when planted in a well-drained, porous
growing medium. Avoid wet/dry cycling of the root ball.
When growing shrubs, we recommend using an aged or
composted pine bark-based media, as opposed to an annual
growing mix that traditionally tend to be heavier in peat. Bark
adds weight and stability to the growing mix and tends not to
compress and shrink over time, thus adding the longevity that
can be needed on long term crops such as shrubs.
LIGHT/LIGHTING
During early spring forcing, plants should be given moderate
to high light. Crops should also be spaced in such a way that
they do not shade each other. Unspaced plants can stretch,
require additional pruning, and lead to an undesirable look on
the retail bench. Producing Deutzia in the summer will require
some shade in the heat. Grow these in areas that can be cooled
adequately and where some shade can be given.
TRIMMING/PINCHING
Deutzia benefit from frequent light pruning, rather than hard
pruning. Avoid pruning except for shape in the early spring.
Once the plants have flowered, additional pruning for shape
can then resume, but stop pruning mid-July to early August so
plants have time to set spring flower buds.
GROWTH REGULATORS
Avoid pinching until after flowering because flowers appear
only on terminals that have been properly vernalized. Light
tip pinching and trimming is used mostly on Deutzia to control
plant height after flowering, as most of the varieties are
naturally compact. Cultural practices such as cooler holding
temperatures, proper spacing and good air movement in an
open environment can also help control plant height and assist
in finishing a high-quality crop.

The rates and chemicals listed are based on our southeast Michigan growing conditions, and are not recommended for nationwide application.
Please adjust the rates and spray applications to your location and facility.

Four Star Culture Guide - 2019

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