Four Star Culture Guide - 2019 - 63

VERBENA CONTINUED
GROWTH REGULATORS
Either a light spray of Sumagic at 5ppm - 10ppm or a
1ppm - 2ppm Bonzi drench can be applied to control growth,
as required. 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
(three to four 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.

PEST and DISEASE MANAGEMENT
Whiteflies, Thrips, 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.

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 fewer PGR
treatments than 104 Liners.

* Supernova treated liners are highly recommended for
growers' small container production.

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.
PGR requirements vary between the Superbena and Royale
Superbena varieties. For supplying proper watering practices
and PGR applications, they can be grown in the following three
groupings:
1) Coral Red, Large Lilac Blue, Pink Shades, Purple and Violet Ice
are more vigorous and can require more PGR attention and
treatment. Large Lilac Blue is most vigorous of this group.
2) Dark Blue, Raspberry, Red, Scarlet Star, Sparkling® Amethyst,
Sparkling® Ruby, Stormburst, Violet Ice and Whiteout™ are
moderately vigorous and can require some PGR treatments
based on timing and growing conditions. Violet Ice within this
group should be watched as an indicator plant.

OUTDOOR GROWING SCHEDULE
Superbena Verbena should be grown outdoors only after
the danger of frost has passed 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

* 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.
* Superbena are fairly heavy feeders and especially the more
vigorous varieties need to be fed on a regular basis with
adequate fertilizer levels to maintain proper growth and leaf
coloration.
* Coral Red, Royale Chambray, and Royale Iced Cherry
can flower slower than other Superbena or Royale
types. Royale Iced Cherry is the most compact Royale.
* Scout for Powdery Mildew. Consider a preventative
treatment with a material such as Compass® (trifloxystrobin).

3) Royale® Chambray, Cherryburst, Iced Cherry, Peachy Keen,
Plum Wine and Romance are less vigorous and should require
little to no PGR treatments. Royale® Iced Cherry is the least
vigorous of this group and should require no PGR treatments
in most cases.

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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