Cauliflower
Brassica oleracea var. botrytis
Cauliflower is one of the more demanding brassicas, requiring consistently moist, fertile soil and a long, uninterrupted growing season to form good curds. Any check to growth - drought, cold snap, or nutrient shortage - can cause small, loose, or discoloured heads. A well-grown cauliflower produces impressive, densely packed curds and a wide range of varieties covers summer through to spring harvest.
Key facts
- Family
- Brassicaceae (Brassicas)
- Category
- Leafy
- Sowing window
- Feb–Jun
- Sowing depth
- 10 mm
- Watering
- medium
- Frost sensitivity
- medium
- Days to maturity
- 80-120 days from transplant
- Harvest window
- Jun - Nov
Sowing notes
- -Sow in modules and transplant after 4-5 weeks
- -Needs consistent moisture - drought check triggers premature curding
- -Tie outer leaves over developing curds to protect from sun and frost
Varieties
All Year Round is a reliable, dual-purpose cauliflower that can be sown in succession to provide summer, autumn, and even early winter harvests. It produces medium-sized, solid white curds and is more adaptable and forgiving than many cauliflower varieties. A good choice for beginners tackling this demanding crop.
Graffiti is a striking purple cauliflower that holds its colour even after cooking, making it as ornamental as it is useful. It is more forgiving than white cauliflower and has a slightly sweeter, nuttier flavour. The vivid colour is caused by anthocyanins and intensifies in cold weather.
Issues & threats
Wilting
EnvironmentalPlants are drooping or losing vigour. Most commonly caused by water stress but can also indicate root damage, vascular disease, or heat scorch. Identifying the cause quickly is important as some causes are serious.
Poor germination
EnvironmentalSeeds are emerging unevenly or not at all. Usually caused by soil temperature being too low, seeds sown too deep, poor seed-to-soil contact, or old seed stock.
Damping off
Fungal diseasePythium spp. / Phytophthora spp.
Young seedlings collapse at or just below soil level, caused by fungal pathogens that thrive in overwatered, poorly ventilated growing conditions. Can spread rapidly through a seed tray.
Yellowing leaves
EnvironmentalLeaves are turning yellow, which can indicate a range of problems including nutrient deficiency, overwatering, disease, or natural senescence. Identifying whether the pattern is upper or lower leaves, whole leaves or between veins, is key to diagnosis.
Stunted growth
EnvironmentalPlants are significantly smaller or slower to develop than expected. May be caused by poor soil, nutrient deficiency, root restriction, compaction, pest damage to roots, or disease.
Clubroot
Fungal diseasePlasmodiophora brassicae
A severe soil-borne disease causing grotesque swelling and distortion of brassica roots. Infected plants cannot take up water or nutrients effectively and typically collapse or die back. Spores survive in soil for up to 20 years. One of the most serious diseases affecting the brassica family.
Aphids
PestSmall sap-sucking insects that colonise soft new growth, leaf undersides, and growing tips. Most species reproduce rapidly and colonies can establish quickly in spring and early summer. Also vectors of several plant viruses.
Chewing damage
PestGeneral chewing damage from an unidentified pest, leaving holes or missing leaf sections. May be caused by caterpillars, beetles, or other insects. Inspect at dusk to identify the culprit.
Sap-sucking pests
PestGeneral sap-feeding pest activity causing weakened or distorted growth. May be caused by aphids, whitefly, scale insects, or other sucking insects. Inspect leaf undersides and growing tips to identify the pest.