Wednesday, December 5, 2007

Greenhouse - Gerber Daisies

I have always had a love for Gerber daisies as a greenhouse cut flower and pot plant crop. I think there is potential for more gerber growers in Delaware. The following is a short article on gerber daisy production.

Notes from the February 20, 2007 Maryland Cut Flowers Growers Meeting


Ronald Smith, Terra Nigra, Carpinteria, CA, gave a presentation on growing gerberas. Terra Nigra’s major crop worldwide is roses, but in the United States their main crop is gerbera daisies. This fall they will also have ranunculus available.

Gerberas will have constant production (in six week cycles) for about three years. In the US, 90% of the gerberas sold are the standard type which produces about 30 flowers per plant per year. The germini type has smaller flowers that are 2.8-3.2 inches and produces about 60 stems per plant per year. The new introductions of the gerrondo type looks like a zinnia or a dahlia bloom. About 15 new varieties are released every 3 years. Red is continually the most popular flower color (20%). Hot pink and orange are increasing in demand. Yellow is decreasing in demand and growers generally have too much of peach and apricot (only 2%). Locally grown gerberas have strong stems so there should be no need for plastic straws for support. Harvest when the second ring of stamens open. The vase life for gerberas is about 12 to 14 days. When they are boxed and shipped dry, dehydration can be a problem. It is important to re-cut stems and then re-hydrate them for at least 4 hours (overnight is best). When growing gerberas, good drainage is very important to get plenty of oxygen into the root zone. Crops are grown in 3’raised beds or in hydroponics systems. Some growers have made custom rack frames out of rebar to suspend one gallon pots with drip tubes over the beds which allows for the water to run through more easily. Maintaining the proper pH between 5.3 and 5.7 is critical when growing gerberas. A high pH causes chlorotic foliage and decreases production. Gerberas are light feeders. The optimal EC level is 1.0 to 1.6.mS/cm. High light levels are needed to increase production when growing gerberas, but diffuse light (about 50% shade) is better. Scorched foliage or wilted plants can occur if light levels are too high or change suddenly. Gerberas are grown under cover and not in field production. Broad mites, leafminers, and whiteflies are common pests of gerberas. They can also get aphids, spider mites, and thrips. Slugs and snails are sometimes a problem in production systems. Disease problems include botrytis, powdery mildew and root rots.

Article from February 23, 2007 edition of the Greenhouse TPM/IPM Weekly Report from the University of Maryland Cooperative Extension.

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