Not long ago, orchids were regarded as rare and exotic. These days, thanks to new propagation techniques, certain varieties are mass-produced and widely sold by supermarkets and other retailers. Orchids are now the most popular blooming flower in the world, according to Marc Hachadourian, the senior orchid curator at the New York Botanical Garden. Orchid flowers can last for weeks. Once the flowers die, it’s tempting to toss the plant. But you can get that $10 orchid to bloom again. Just be patient. It might take a year. The main tip for growing orchids is not to overwater them.