Remove weeds, large rocks, and litter from the planting area. Till the soil 8-10 inches deep and rake several times to break up large clods. It is best to do this when the soil is dry enough to not stick to garden tools. Loosening the soil will help the plant establish strong roots.
Start seeds indoors in small containers 8-12 weeks before last frost, keeping the soil temperature at 65F. Harden off, then transplant seedlings after last average frost in Spring. Direct sowing outdoors and Fall planting is possible for warmer climates.
Watering: Water plants moderately. If the soil moisture is low, water but avoid waterlogging soil.
Weeding: Keep plants free of weeds, which rob weak root systems of nutrients and moisture.
Insecticides: Insecticides may be used to protect plants. Bt-based insecticides and sulfur are organic options that can be used for prevention. Sevin is a synthetic option. Sulfur also has fungicidal properties and helps in controlling many diseases. Before using a pesticide, please read the label and always follow cautions, warnings and directions.
Diseases: Disease can happen in cloudy, damp weather. Check plants daily and treat with an approved fungicide if diseases do appear. Neem oil, sulfur, and other fungicides are available for use. Please always follow label directions.
Harvest cardoon by cutting the plant at the base, below the crown. Remove the excess loose leaves and pull away at the outer layers of stalks to reveal the core stalks. Optionally, blanch the cardoon by tying the cardoon core stalks at the top then wrapping in thick fabric or plastic for 4-5 weeks. This optional process is said to whiten the colors of the stalks and reduce bitterness.