Planting, seed and seedlings
Celery is planted all year on the coastal plain but best yields and quality are obtained from late February to August plantings.
It contains a glycoside which can give a bitter taste at some times of the year, especially in spring.
Celery is not sown directly in the field and seedlings in cell-packs have replaced the traditional method of using open seedbeds. Most growers purchase plants from nurseries, but some produce their own cell-pack seedlings.
If using seed, treat seed less than three years old with hot water at 50°C for 30 minutes the day before sowing to control Septoria leaf spot disease. Dry rapidly after treatment and dust the dry seed with a fungicide registered for this use before planting.
Seedlings should be ready for planting four to five weeks after pricking out. The best size for planting is at the four-leaf stage.
Planting and rotations
Celery seedlings are normally planted by machine. Hand planting usually gives more uniform establishment but is more expensive.
The crop is typically grown in three or four row beds with 1.5–1.65m between tractor wheeltrack centres. Aim for a spacing of around 40cm between rows and 40–45cm between plants within the row. Wider spacings are preferable for winter plantings to minimise fungal disease.
It is possible to grow one crop of celery on the same ground each year if it is rotated with other crops for the rest of the year. Adopt a longer rotation if yields are declining.