The most common types of Zantedeschia are; aethiopica & elliottiana
aethiopica; is a half hardy perennial with plain green leaves that flowers March to June and is not to be confused with elliottiana; a half hardy perennial with speckled leaves that flowers from May to June.
Cultivation;
|
|
Week 13; In Spring when growth appears, water moderately gradually increasing the amount until the plants are in full leaf,
then water copiously.
When flowering is over gradually withhold water.
Feed at weekly intervals from May to August with a balanced or high potash liquid fertiliser.
Week 38 - 42; Fetch them back into the greenhouse and pot up in fresh compost.
The rhizomes can then be divided and potted up then stored in their pots under the greenhouse staging.
Zantedeschia elliottiana;
Is a half hardy perennial with speckled leaves and flowers May to June.
They require minimum winter temperature of 8°- 10°C (45°-50°F)
When the leaves have turned yellow, store the rhizomes in their pots under the greenhouse staging.
Week 13; When growth appears water moderately.
Gradually increase the amount until the plants are in full leaf then water copiously.
Week 22; Feed at weekly intervals from now until July with a balanced liquid fertiliser.
When flowering is over gradually withhold water, giving no water after mid July.
Week 38; Re-pot established plants, divide the rhizomes now and pot up the offsets immediately.
Week 42>; move containerised plants into a frost free area for the winter.
Pests and diseases;
Calla lily soft rot is the most common disease to affect bulbs.
This is caused by the Erwinia caratovera bacterium.
Once infected, there is no chemical or other control method that will rid the tuber of this bacterium.
Good hygiene, air and soil temperature,and watering control is the best prevetative course of action to keep this disease at bay.
Thrips and aphids can pose a problem.
To prevent the spread of viruses and fungal diseases spray the plants with a suitable insecticide as the flower spikes emerge.
Repeat this at 7-10 day intervals.
Temperature;
They require a minimum winter temperature of 4°-8°C (40°-45°F)
The ideal day/night temperature during the growing season is; 18°-24°C (65°-75°F) / 12°-18°C(55°-65°F) where the soil is around 18°C (65°F) but below 24°C (75°F)
Preventitive measures such as shading and mulches can be beneficial.
Compost / Soil;
They prefer loose, free draining soils with a pH of 6-6.5.
If drainage is a problem,place some grit under the bulb and into the surrounding soil/compost.
Alternatively; plant into containers or raised beds.
If the soil becomes contaminated with the erwinia spores do not plant callas in that area for a number of years after.
Watering;
Plants should be kept just damp Until leaves unfurl,
Increase watering as the leaves open, and water regularly during the growing season to avoid the stress that may be caused if they become too dry.
Ease off with the watering after flowering and as the plant begins to die back.
Nutrition;
Avoid high nitrogen fertilsers as this leads to soft growth that is more susceptible to disease.
Add a weekly balanced or high potash feed from the time the leaves begin to unfurl until flowering is over.
