Harvesting is labour intensive and demands considerable time and expertise that doesn't exist in New Zealand's culture, she says.
Processing also demands expertise and Zealong's craftsman tea-makers are recruited from Taiwan's tea-growing regions. Skilled in the art of tea production, from picking and drying to grading and packing, they oversee local and Taiwanese seasonal tea pickers and maintain high standards. Even picking the crop is not just something anyone can do, says Crawford.
"Tea is much different to harvest than other crops and the pickers really have to be motivated because they have to work day and night during the harvesting season.
"Nobody thinks about these things when they look into growing tea. A lot of Kiwi people talk to us about it, but they don't realise how difficult it can be. It's a bit like being a winemaker, it's no overnight thing."
Grown organically, Zealong's range of high quality teas must fill a niche market as there is no way this country can compete with traditional tea-growing countries' vast-scale marketing.
"In New Zealand, you have to provide added value and we just can't compete as far as production costs are concerned. For investors to succeed can involve a very delicate balance," says Crawford.
Fussy about the soil it grows in, tea also prefers a consistent climate with few temperature variations between day and night. Planting is expensive and the cost of setting up processing plants is huge.
Zealong founder Vincent Chen faced huge challenges when he first tried to grow tea in the Waikato, on a 3ha site just outside Hamilton.
His father, Tzu Chen, had noticed that camellia trees, which grow in similar conditions, flourished in the area and thought it would be easy to import tea plants and start growing and processing.
The two imported 1500 plants from Taiwan but after a lengthy period in quarantine, most of them died. Help from a Taiwan propagation expert and a Kiwi plant scientist turned that situation around, but there were still numerous difficulties to overcome before their tea house and plantation was set up.
Crawford says new challenges constantly have to be overcome and Zealong, which has a reputation for clever marketing that leans heavily on New Zealand's clean, green image, is working on extending its marketing network through other countries, including in Germany, France, Taiwan, China and Hong Kong.
"We don't want to scare other people off growing tea, but it certainly isn't easy."