November 2019 - 32

CULTURE REPORT
Osteospermum
Bright Lights Series
T
he Bright Lights collection of osteospermum is focused on
the pursuit of heat tolerance and improved habit that only
the newer breeding of this genus offers. The collection
containers six colors: Yellow, Pink, Double Moonglow and (new in
2019) White, Berry Rose and Purple. As with all of our collections
the selection process is both consumer and grower based -
focusing on extending the season and range of the crop, as well as
selecting grower level characteristics such as habit, early blooming
times and ease of production.
Osteospermum come from South Africa originally, and, contrary
to what you might think, this does not mean they came from hot,
steamy jungles. In fact, it is just the opposite in that South Africa
is a land of desert to Mediterranean climates, mostly dry with very
definite seasons determined by rainfall and temperature changes.
Osteospermum are naturally a spring flower in South Africa, so
they bloom as temperatures begin to warm after a cold, but not
freezing, winter. Most osteospermum can tolerate temperatures in
the high 30s Fahrenheit with no problems at all.
In fact, low temperature is a great tool for controlling the crop. If
you grow using DIF; a negative DIF can be very helpful in keeping
the crop compact. Like most crops, remembering where they
originally came from can help you to provide the best environment
possible when they enter your nursery.
COOLER AND DRIER IS BETTER
Even with advancements in heat tolerance, Bright Lights
This new collection pursues the cutting edge of
osteospermum performance, with resilience and
outstanding shelf life.
BY RICK SCHOELLHORN
osteospermum will shape up into a better crop if you keep
temperatures cool and humidity low with good air circulation. So,
this crop is ideally suited for early production for all growers; as the
season moves into spring and summer the best crops will be those
grown where temperatures can be kept lower.
High humidity is not good for osteospermum; if you find yourself
trying to grow this crop alongside warm temperature/high humidity
preference crops like coleus and ornamental sweet potato you
are likely to have a lower quality crop. The higher temperatures
and humidity promote stem and flower stretch, which in turn
increases the need for plant growth regulators. Keep temperatures
and humidity low for disease prevention, more compact plants
and increased flower count. Watch your watering as well -
osteospermum like to dry a bit between watering, so keep a close
watch on soil moisture.
BRIGHT LIGHTS PREFER BRIGHT LIGHT
High light intensity is also required for high-quality
osteospermum crops - again think of where the crop came from
in high desert light conditions. So, when planning crop placement
in your greenhouse make sure to keep Bright Lights osteospermum
in the brightest light possible. The high light intensity gives you
some key advantages. High light intensity will increase branching,
help keep plants compact (reducing both stem and flower stem, or
peduncle, length), and increase the bud or flower count.
TEMPERATURE MANAGEMENT
A couple temperature tips, if you have the ability to refine your
temperatures by zone within the greenhouse:
During establishment, after transplanting the liners into their
final containers, it can be helpful to run either the greenhouse or
simply the root zone a bit warmer to speed and aid in rooting in.
Raising root zone temperature to 65 to 70° F can speed the crop
32 NOVEMBER 2019 GPNMAG.COM
http://www.GPNMAG.COM
November 2019

Table of Contents for the Digital Edition of November 2019
