Robusta answers the call for full, colorful crops adaptable
for both home and garden with larger leaves and huge flowers, which will satisfy
the needs of floral buyers in addition to stimulating impulse sales at retail.
Robusta's strong and full-bodied habit will easily fill out 6- to 71/2-inch
containers, while the proportionally large blooms create a prolific bouquet of
color. Seven colors make up the series: Fuchsia, Purple, Rose, Salmon, Scarlet,
White and Wine.
Bred for the large-container market, Robusta blooms 2-3
weeks later than the Sierra series, so program Robusta for mid- to late-season
sales (late November through February). Because Robusta's habit is larger than
standard-sized cyclamen, there are a few nuances to growing these super-sized
plants that differ from traditional culture.
Robusta requires partial shade to filtered sun. During the
bright hot days of summer there is a risk after transplant for the plant to
grow too quickly and develop large leaves too soon in the growth cycle. To
avoid excessive leaf development during summer months, it is necessary to grow
Robusta with modified fertility levels.
cyclamen are initially grown at a nitrogen:potassium ratio of 1:1 and gradually
increased to 1:2. During the last third of the Robusta growing cycle increase
nitrogen:potassium ratios to 1:3. With Robusta's larger habit, potassium takes
on a greater role in producing a higher-quality plant.
Potassium is important in the growth of cyclamen because
deficiencies will result in soft growth, and plants are more susceptible to
damage. Potassium is also important in translocating sugars and starches to the
growing tips. Low potassium levels can result in stunted plants. As a general
rule, plants normally absorb potassium during the first half of their growth
cycle. Peak demand for potassium during cyclamen development occurs at bud set.
Plants grown with reduced levels of potassium run the risk of reduced flower
quality and overall shelf life. Optimum potassium levels will increase the
overall flower count on cyclamen, thus creating beautiful bouquets of blooms.
The nitrogen:potassium relationship is important for other
reasons as well. Potassium will counter many of the negatives of nitrogen.
While nitrogen stimulates rapid, soft growth, potassium counters by promoting
firmer tissues. And while nitrogen may increase sensitivity to disease
pressure, potassium increases disease resistance. To anyone who has grown
cyclamen, the importance of promoting strong healthy plants cannot be over
management is important in producing a strong plant. Irrigate Robusta when the
media has changed color from a dark black to a medium brown. After irrigation,
the media should be wet to the touch, but not saturated. Watering early in the
day allows the foliage to dry before nightfall and prevents crown rot. Water is
important in the uptake of potassium into the plant. The diffusion of potassium
is a slow process and occurs through the film of water that surrounds the
roots. Crops kept too dry can appear stunted. However, once absorbed into the
plant, potassium is readily translocated through the plant.
Premium crops require special care. Find out what is needed for this over-sized cyclamen.