How can I stop carrot rust fly eating my carrots?

Hi Rob, the carrot rust fly starts flying around September October and can have 3-4 life cycles in one season, each cycle takes 12 weeks. They lay their eggs in the soil near their food source and when the larvae hatch they burrow down into the soil and cause damage to the crop. Carrot Rust fly is hard to control, the best way is by using cultural practices, there are soil insect control products available from your local garden centre which is sprinkled on the soil around the plants or on the soil at the time of planting. Other things you can do are:

• Rotate crops and not grow carrots in the same spot each season.
• Prepare the soil by sowing a mustard green crop in autumn, dig this into the soil in late winter, mustard contains a substance that repels nematodes and other soil insects for at least three months.
• Make sure the shoulders of the carrots are buried and not above the soil surface to prevent eggs being laid.
• Thinly sow seed, well-spaced out carrots reduce the need to thin, disturbing the soil gives the carrot rust fly an opening to lay its eggs.
• Avoid planting other crops such as parsley, parsnip and celery, which are susceptible to carrot rust fly, too close to carrots or in the same plot.
• Onions, chives, garlic and leeks are good companions to deter carrot rust fly, the pungent smell deters them, plant in between rows.
• There are some carrot varieties that are resistant to carrot rust fly, there is a variety in New Zealand called Resistafly, check with your local garden centre on availability.
• Remove weeds that may harbour carrot rust fly, mulching is a good way to keep weeds down use pea straw or Tui Mulch & Feed.
  Lianne