Exact planning can avoid problems!

Date of delivery

This depends on many factors:

•	Plant specification required
•	Cultivation technique to be applied
•	Availablity of the growing area
•	Proposed marketing period

Here is an example of cultivation for sale at the end of April, in the northern climate
– for the South, approx. 2 weeks should be deducted.

Pot Size	Number of weeks from purchase until sale
6 inch	Zonals: 12-14 / Ivies: 14-16
5 inch	Zonals: 10-12 / Ivies: 12-14
4 inch	Zonals: 8-10 / Ivies: 10-12

Zonals should not be pinched. Ivies should be pinched once!

Unrooted cuttings stuck directly in the pots require approx. 3 additional weeks of cultivation period.



Preparations before the plants arrive

•	Prepare the growing area and disinfect it
•	Provide new and clean pots, used ones need to be disinfected
•	house-warm growing medium

 
Processing of the young plants on arrival

Prompt processing of the young plants and a position with optimal conditions is the precondition for quality!
Pot the plants immediately on receipt!

Should this not be possible:

•	open the boxes immediately on arrival so the plants get light and air
	water dry plants before potting

 
Growing medium

•	Use quality substrates with pre-determined analysis for hygiene reasons
•	Loam potting growing medium can be used, has to be sterilized by steam. Analyze soil before use.
•	Components: 15-25% clay is advantageous:	better buffer better leaf wetness stable pH result: hardier and more compact plants
•	pH:        peat substrate 5.6 - 6.0               clay-peat-substrate 5.8 - 6.2

check pH during the cultivation, as it can vary depending on substrate and hardness of water.

 
Feeding

Start feeding when the first roots are visible at the pot side. Complete fertilizer 15-10-15-2 0,1% in every watering.
Growing medium should be analyzed before first and last feeding.

Optimal amount of nutrients in the substrate (in ppm)

Main nutrients	Start of cultivation period	Middle of cultivation period	End of cultivation period
N	150	200	150-200
P2O5	100	150	100
K2O	180	200	300
MgO	100	150	150

Slow-release fertilizers can be mixed into the soil. However, high temperatures can lead to fast and uncontrolled release of nutrients leading to high amounts of salt and adverse growth.

Temperature

1.	Rooting period, approx. 14 days
	Average temperature during the day	68 °F
	Temperature during the day	72 °F
	Temperature at night	65 °F
	Ventilation temperature	75 °F

2.	Main growing period
	Average temperature during the day	63 °F
	Temperature during the day	65 °F
	Temperature at night	61 °F
	Ventilation temperature	68 °F

3.	Hardening phase, approx 14 days before sale By hardening, the vegetative growth will be reduced and the plant quality will be maintained until sale.
	Average temperature during the day	59 °F
	Temperature during the day	61 °F
	Temperature at night	57 °F
	Ventilation temperature	65 °F

 
Air humidity

Avoid too high a relative humidity in the greenhouses as this reduces plant transpiration.

This will lead to:

•	nutrients not being absorbed
•	diseases
•	disturbed growth habit
•	too low transpiration
•	high pressure inside the cells (turgo pressure) leading to cell rupture
•	perliferation, oedemas
•	soft and puffy plants by large cells
•	high risk of rotting by Botrytis

Causes:

•	highly insulated greenhouses with energy-saving glass: Minimum exchange of air through joins and holes Humidity will stay in the greenhouse
•	Watering of slabs and sand beds:    open water-bearing surfaces – humid areas emit a lot of water vapour
•	Too great a difference between heating and ventilation temperatures

Remedies:

•	Reduce air humidity in the greenhouse by: Covering the slabs and sand beds with anti-algae film Avoiding water under the benches
•	Avoid too sharp a reduction of temperature at night – (falls below the dew point!)
•	Ventilate: a) by hand: Open ventilation twice a day for approx. 15 minutes to 20%. b) computerized: input of the percentage of the humidity 80%, start
Temperature of ventilation max. 7 °F higher than heating temperature

Light

Geranium flowering is light-dependent	better growth and abundant flowering during high light periods assimilation starts from 1.500 Lux
Optimal:	the best assimilation in geraniums will be reached between 25.000 and 35.000 Lux
Shading:	only to be applied in case of direct sun, if plant protection or growth retardants are used or if the light intensity reaches 50.000 Lux or more.

 
Pinching

1. Zonals	the varieties in our assortment do not require pinching as they are free breaking Exception: plants in pots larger than 6 inch for fuller plants
2. Ivies:	Pinch 10-14 days after potting. Late pinching will delay flowering!

 
Growth regulation

1. Use of growth retardants
1.1. Spraying e.g. CCC 0,15%
Z o n a l s: every 1-2 weeks, depending on weather conditions
I v i e s: every 1-2 weeks, depending on weather conditions
Start spraying:
    • cuttings directly stuck in the pot: 3 weeks after sticking
    • rooted cuttings planted in the pot: 1 week after potting
Concentration and frequency depend on the variety and the stage of development in the plant.

1.2. Preconditions for the use of CCC:
Roots have to be kept moist 48 hours before and after the treatment!!
Roots must be well developed.
Temperature of at least 59 °F for 14 hours
Avoid direct sun: spray on cloudy days or very early in the morning
Shade from 10.000 Lux and assure good ventilation
Spray in the morning, then plants will be dry in the evening to avoid Botritys.
The leaves are cooler in the morning than in the evening.

2. Growth retardance without chemicals
Why?
• increasing ecological awareness of the population
• increasing ecological awareness of the cultivators
• future total prohibition of growth retardants
• Growth retardants can lead to damage of the plants


Measures:
2.1. Choice of varieties
This depends on the required production criteria: compact, medium, vigorous varieties.
Plant, pot and production period have to be chosen correctly.

2.2. Water
Elongation growth can be reduced by lower supply of water
Avoid totally drying of plants because this leads to yellow leaves.

2.3. Temperature
"Negative-Diff":
•High temperatures during the day and low temperatures at night lead to elongation growth.
•High temperatures at night and low temperatures during the day lead to reduced elongation growth.

Temperature during the day: 58 °F,
Temperature at night: 65 °F 7°F difference.

Higher temperatures at night will moreover avoid to exceed the dew point and therefore reduce the risk of Botrytis.



2.4 Cool-Morning:
Extreme reduction of temperature from sunrise and up to 2 hours before in order to reduce the average temperature during the day.
Reduction from 61 °F to 50 °F for 4 hours.
Very useful measure in spring because of the relatively cold early morning hours.

More efficient and economic temperature strategy than the above-mentioned, as no additional heating at night is necessary in order to keep night temperatures higher, and day temperatures do not have to be kept low.



2.5 Combination:
Both Cool-Morning and Negative-Diff can also be used. So the average temperature during the day can be achieved through increasing night temperatures.

Day Temperature	10-17 h	63°F
Night Temperature	17-6 h	67°F
Cool-Morning	6-10 h	50-54°F

All recommendations are made with regard to the best of our knowledge. We cannot accept any responsibility for the correctness of this information. Please pay attention to the indications and the publications of the local plant protection authorities and advisory services.