Triflor assistant crop manager Theun de Dood said when the weather allowed, Triflor staff were spraying flowers showing signs of tulip breaking virus (TBV) and tulip virus X (TVX) in Edendale.
Killing any affected flowers and bulbs ensured all the remaining tulips stayed healthy, he said.
More than 110ha of tulips were grown by Triflor in Edendale and the bulbs were exported across the world.
Back-to-back wet spring weather had required patience to grow the flowers.
"You have to be patient with spraying, virusing and debudding and hopefully the weather will turn around."
The land required to grow the tulips was leased from farmers in Edendale.
He asked the public to not go into paddocks to take photographs as they were private property.
Tulip crops could only be planted in the same paddock once every seven years to control diseases, such as fusarium, also known as bulb rot, which could damage up to 40% of a crop.
The paddocks used to grow the tulips were mostly on dairy farms.
"We like to choose the dairy farms because of the rich soil — the richer the soil, the better the tulips will grow."
