Four Star Culture Guide - 2019 - 61

VERBENA CONTINUED
GROWTH REGULATORS
Either a light spray of Sumagic at 5ppm - 10ppm or a 1ppm
Bonzi drench can be applied to control growth, as required.
In most cases, Lanai Verbena will require fewer PGRs than
the average standard Superbena®. They are most similar to
Superbena Royale Peachy Keen in vigor. Treatments are usually
made to smaller containers seven to 14 days after planting.
Treatments to larger containers can be made when a desired
"pre-finished" size is attained (two to three weeks before
scheduled finish date). Watch for the "softening" look and
lighter green appearance of new growth as an indication for
PGR treatment needs. In more northern areas, the lower rates
should be used as a starting base, while in more southern
areas, the higher rates will probably be needed. Other materials
such as Topflor® (flurprimidol), and Piccolo® (paclobutrazol) can
be used at rates that correspond with the degree of treatment
recommended for Sumagic or Bonzi.
Proper growing temperatures, high light levels, proper spacing,
and good growing practices can be very helpful at managing
plant size. Supernova treated plants should require less PGR
treatments than 104 Liners.
When using Supernova Liners, please refer to the
Supernova Culture Guide for specific PGR and growing
temperature recommendations. Florel® (ethephon) is not
recommended for use with Supernovas, except possibly
with Nemesia.

OUTDOOR GROWING SCHEDULE
Lanai Verbena should be grown outdoors only after the danger
of frost has past and weather is consistently warm (mid- to
late May in Michigan). The foliage can be damaged from a very
light frost. This recommendation is based on average spring
weather and should be adjusted for unseasonably severe or
unseasonably mild conditions.
OTHER TIPS
* Supernova treated liners are highly recommended for
growers' small container production.
* For best combination planting performance, consider
vigor for all plants used, especially if mixing
Supernova treated plants in with non-Supernova
treated plants.
* Maintain proper soil pH levels. A soil pH below the upper 5s
can lead to iron toxicity. This will show in the older foliage as
a fine rusty to brown leaf spotting.
* Avoid long periods of cool, wet, humid, and low light levels in
the greenhouse, if possible, when growing Verbena. Various
diseases can develop, especially if proper air movement is
not provided. Also, under these growing conditions, proper
fertilizer levels in the soil and plant must be maintained or
foliage will discolor or develop a "spotting" pattern.

PEST and DISEASE MANAGEMENT
Whitefly, Thrip, and Aphids can be an issue. Preventative
treatments or regular scouting should be considered. Proper
growing environments and watering practices should be
followed to avoid Botrytis, Powdery Mildew, and various Stem
or Root Rots. A preventative Powdery Mildew treatment with a
material such as Compass® (trifloxystrobin) can also be helpful.

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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