The Dutch distinguished three types of broken tulips:
- Bijbloemens, purple on white
- Roses, red to pink on white
- Bizarres, brown, purple or red on yellow
In the early 16th century, botany was a fledgling science and no one knew what caused the wild and subtle coloration of the most coveted broken tulips, but one thing was certain: the best of these flowers commanded prices as high as the cost of a grand house on one of Amsterdam’s main canals. Love and greed for these spectacular, expensive flowers drove collectors and breeders to experiments that might provoke such alchemy. They applied strange concoctions to planting beds or individual bulbs – pigeon dung, old plaster, manure, dishwater, even powdered paint. Tulip bulbs were exposed to the elements, planted in poor soil, soil imported from distant lands, or beds where broken flowers had bloomed. Some bulbs were planted too deeply or in too little earth, but nothing anyone could devise seemed to guarantee a break. Breeders came closest to success when they bound bulbs of broken and unbroken tulips together, generally to the detriment of each, but very occasionally a survivor of this process would break into the coveted flames.
Broken bulbs did produce identical plants through offsets, but the plants were often weakened by virus and reproduced at a slower rate than single color flowers. The difficulty of propagating broken bulbs significantly increased the perceived value of the flamed beauties.
In 1928, a researcher in London discovered that an aphid-borne disease, finally identified as a form of mosaic virus in the 1960s, caused breaking. The virus causes a mixture of fading and excess pigmentation on the surfaces of each petal of a tulip flower. The beautiful patterns on the inside and outside of each petal may bear little resemblance to each other. The virus also causes a gradual weakening of the bulb, reducing the number and strength of offsets. With time, a broken tulip is more likely to die out than to multiply.
Once the cause of breaking was known, and the ill effects of the virus confirmed, breeders recognized that broken flowers posed a threat to the health of their tulip beds. They began to weed out and destroy the kinds of flowers they had once valued above all others. Today, very few breeders raise broken tulips of any kind, though a few specialty bulb collections still make them available to home gardeners and many commercial breeders offer hybrids that approximate the exhilarating beauty of broken flowers.