Cultivation guide Aster
General information
The Royal Van Zanten Aster varieties are short day plants,
suitable for greenhouse culture. Aster can be used both as a
houseplant and a garden plant. In the garden, Aster can be
used in pots or as a bedding plant, where it flowers beautifully
for several weeks. The plant demands little maintenance.
Cultivation can be started from week 5 using assimilation
lighting and from week 12 using cyclic lighting (15 watts per
m2).
Royal Van Zanten has two series available: Aster Crown® and
Aster Tiara®. The Crown® series is a single flowered vigorous
series; the Tiara® series is a compact growing single flowered
well branched series which requires little growth regulator
(PGR)).
The following varieties are available:
Crown® series
 Aster Crown® Duke
 Aster Crown® Diamond
-
pink
white

Aster Crown® Dynasty
Aster Crown® Fortuna
-
purple
dark pink

Aster Crown® Comtessa
-
white
Tiara® series
 Aster Tiara® Orchid Pink
-
pink
Aster Tiara® Azure
-
light blue

Aster Tiara® Indigo
Aster Tiara® Royal Purple
-
dark blue
purple blue

Aster Tiara® Royal Pink
-
pink



Cultivation
The instructions below are based on greenhouse culture under
Dutch climatic conditions.
Starting material
Aster cuttings are supplied unrooted. They are delivered in
units of 250 with 50 cuttings per bag.
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Pot size
Aster Crown® and Aster Tiara® can be cultivated in different
pot sizes. Most commonly used are 12 cm pots in which 3
cuttings per pot are stuck. However, it is also possible to grow
them in packs and in larger pot sizes and dishes. A new type
of cultivation is the Carnaval mix with 3 different varieties per
pot.
By selecting the right combination of the number of cuttings
per pot, the number of times the plants are pinched back and
the use of growth regulator, the desired model can be created.
We can supply you with specific advice on this.
Rooting
Depending on the season, the Asters are illuminated up to a
day length of 18 hours. Aster Crown® and Tiara® are stuck in
an airy water permeable compost mixture to which a slowrelease fertilizer is added, e.g. 5 kg Dolokal and 1 kg PG-mix
per m³. After sticking, the plants are covered until week 15 with
a transparent foil and after this with a milky white foil which
does not touch the cuttings. Rooting takes +/- 7 days. It is not
necessary to treat the cuttings for botrytis immediately after
sticking. Once the cuttings have rooted, the foil can be
removed. This is preferably done in the evening.
Pinching
Plants grown in a 12 cm pot are pinched back to 5-6 leaf pairs
after 13-14 days. As soon as they are spaced out at their final
distance, they are pinched/mowed once more or if necessary
twice.
Plants grown in a 17-19 cm pot (with 3 cuttings per pot) are
usually pinched back 4 times.
Spacing
Spacing takes place 5-7 days after pinching and immediately
in the short day. At this stage, the plants have had a long day
period of 18-21 days.
The final distance is as follows:


10.5 cm pots are spaced at a density of 24-28 per m²
12 cm pots are spaced at a density of 22-26 per m²
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Climate
For Aster Crown® and Tiara®, a day temperature of 19ºC and
a night temperature of 21ºC are maintained. The venting
temperature is 1ºC higher. The automatic ventilation
temperature can be supplemented with a 4-6ºC light
dependent temperature control. In connection with the
susceptibility to mildew it is advisable to keep the relative
humidity below 85%. Because mildew may also occur as a
result of too much ventilation, it is recommended to limit
ventilation on the side where the wind prevails in cases of
windy weather.
Growth regulators
Inhibition takes place for the first time one week after pinching
in a dosage of 200-300 gram Alar per 100 litres of water. You
need to inhibit maximally 3-4 times during the cultivation
period.
Crown® series
Crown® Diamond is the most vigorous variety, followed by
Duke and next Dynasty, Fortuna and Comtessa. The target
height of Aster Crown® varieties is 25-30 cm (bottom pot to
flower).
Tiara® series
In general, the Tiara® series is more compact than the
Crown® series. Orchid Pink is the most compact Tiara®
variety. The other varieties are of similar vigour.
Fertilization
Supplementary fertilizer is given in a K-N proportion of 1 : 2.
The EC is set to 1.5 – 2.0.
Target values for the fertilization of Aster Crown® in mmol:
EC
0.8
PH
5.8
SO4
HCO P
3
0.5
0.5
0.8
NH4
<0.1
K
1.6
Na
<1.0
Ca
1.2
Mg
0.5
NO3
4.0
Fe
Mn
Zn
B
Cu
8.0
2.0
2.0
15
0.7
Cl
<1.0
Blackout
Aster Crown® and Tiara® are both short day series, meaning
that the plants only form flowers when nights are longer than
days. In order to achieve bud formation, a blackout of 13 hours
per day is required. For example from 6 pm until 7 am. If
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necessary, a moisture gap can be created. This has to be
done 1.15 hrs after sundown and 1.15 hrs before sunup.
The standard reaction time of these varieties is 5.5 weeks.
Variety Crown® Diamond forms the exception with a reaction
time of 6.5 weeks.
Crop protection
As is well-known, Asters are susceptible to mildew and
preventative spraying is required. Good results have been
achieved with Kenbyo (kresoxim- methyl).
Please note: Asters are sensitive to Euparene (tolyfluanid)
Apart from this, you have to be attentive to aphids, thrips and
leafminers.
Marketing
Aster Crown® and Tiara® can be sold with as well as without
sleeve.
In conclusion
Royal Van Zanten wishes you every success in the cultivation
of Aster Crown® and/or Tiara®
This cultivation description is only intended for your
information. Royal Van Zanten cannot be held responsible for
any problems resulting from said advice.
More information:
Royal van Zanten
Van Zanten Cuttings B.V.
Rijshornstraaat 205
1435 HH Rijsenhout
The Netherlands
Telephone +31(0) 297 389 600
Fax
+31(0) 297 389 610
Email
pot.bedding@royalvanzanten.com
Website:
www.royalvanzanten.com
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