There is an increasing interest in Southern Italy to grow Calla Lilies. Warmer temperatures and high light intensities enable growers in the south of Italy to produce flowers all-year-round in a relatively short production cycle. The result is a considerable economic advantage over production in Holland especially between October and March when the demand is high together with good export opportunities.

Calla tubers are normally planted in a fertile free-draining natural soil. Growing media which is a combination of composted pinebark or peat, plus pumice, perlite or vermiculite is also popular. Some growers using soil, add a mulch of clean pine sawdust or rice husks over the surface to reduce soil heat, retain soil moisture and reduce weeds. The ideal pH is 6-6.5. Controlled release fertilizers work well and in general, plants respond well to foliar and liquid feeding. High nitrogen levels are to be avoided.

It is essential to use clean, virus-free tubers, that have been correctly treated and stored during dormancy. For growers who re-use theirm own tubers, prior to planting, the tubers are removed from storage and warmed to 20-25°C for two weeks to trigger growth. Tubers are then treated with Giberellic acid (GA3) to achieve pre-germination which can increase flower initiation by up to 300%.

In general a lower density planting of tubers will result in more, larger flowers per tuber and greater tuber multiplication, athough many growers prefer a less expensive grade of tuber (3-4cm) that can be grown at higher density. The variety 'Black Eyed Beauty' is claimed to be the most resistant variety to the pathogen Erwinia and is one of the easiest to grow. For pot plant production, 3 - 4 smaller tubers of a 2-2.5cm grade are planted in each pot. The variety 'Crystal Blush' is recommended by F.lli Osma (Campania) for pot cultivation; just one tuber will produce up to 18 flowers (white at the start and later white with pink margins).

Light is a critical factor with calla lilies. Low light will result in lower yields, duller colours, reduced plant growth and tuber multiplication. Optimum outside light levels are about 50,000 Lux. In the daytime greenhouse shading 30-50% will usually be required in the hotter months to keep the air and soil temperature down. Plastic cladding or glass should be kept clean to enable maximum light transmission during dull weather. The critical temperature at the canopy level of the crop is 18-25°C (day) and 12-18°C (night) and 18°-19°C at the depth of the tubers in the soil (with an upper limit of 23°C. Lower night temperatures will enhance flower colour, notably in pink and red varieties. Low soil temperature may reduce yield and the strength of the stems. Air temperatures the the greenhouse may rise above 30°C but good horizontal movement of the air is essential. Plants should be regularly watered but the soil should not be allowed to become sodden. It is best to irrigate in the morning and again, as required, in the late afternoon.

A preventative spray program to control insects and diseases is normally started prior to the emegence of the spike and repeated at intervals of 7-10 days and every 3 weeks after flowering. Most insecticides can be combined with fungicides and certain foliar fertilizers. Calla lilies can be attacked at the root zone by Pythium, Fusarium, Rhizoctonia and Phythophora and if weakened or stressed, secondary infection by Erwinea is common. Any plants affected with virus should be pulled up and burnt. Symptoms include strop shaped and distorted leaves and variegated mosaic patterns.

Flowers are normally picked in the cool of the morning or evening. They are pulled rater than cut to ensure the longest possible stem length. After appr