How to grow broccoli in a greenhouse? When to plant and how to care for it?

Broccoli is one of the healthiest types of cabbage, rich in vitamins and antioxidants. Growing in a greenhouse allows you to harvest almost all year round, protecting plants from sudden temperature changes and pests. However, for successful cultivation of broccoli, it is important to observe certain conditions, take into account the temperature regime, soil, fertilizers and methods of protection against diseases.

Optimal conditions for growing broccoli in a greenhouse

Temperature conditions

• The optimal temperature for growth is +16…+22°C.
• At temperatures below +10°C growth slows down.
• At +25°C and above, the inflorescences begin to loosen and the taste deteriorates.
• After the head has formed, broccoli can withstand short-term frosts down to -5°C.

Humidity and watering

• Air humidity: 65–75%.
• Soil moisture: 70–80%.
• It is critical to avoid sudden changes in humidity, as this can cause the inflorescences to crack.
• The optimal irrigation method is drip irrigation, which ensures uniform soil moisture.

Lighting

• Broccoli needs 12-14 hours of light per day.
• If there is insufficient light, the heads form loosely.
• In winter, additional lighting with phytolamps is required (LED lamps with a cold spectrum are best suited).

Tip: To protect plants from overheating in summer, use shade net 30–40%.

Timing of planting broccoli in a greenhouse

Growing broccoli in a greenhouse is possible in several stages, depending on the time of year:

• In spring – sowing in February-March, transplanting in April.
• In summer – sowing in June-July for autumn harvesting.
• In autumn – sowing in August-September for winter harvesting (if there is heating in the greenhouse).

Tip: To harvest broccoli all season long, use the conveyor method, sowing seeds every 2 weeks.

Choosing a broccoli variety for a greenhouse

Type of broccoli	The best varieties for a greenhouse	Peculiarities
Early ripening	"Tonus", "Lord F1", "Monterey F1"	Ripens in 60-80 days, suitable for early spring and autumn.
Mid-season	"Fiesta", "Emperor F1", "Calabrese"	They ripen in 90–100 days and form large heads.
Late ripening	"Perfume", "Marathon F1"	They require longer cultivation, but produce dense inflorescences.

Tip: For year-round growing, combine early and late varieties.

Technology of planting broccoli in a greenhouse

Soil preparation

Quality soil is the foundation for healthy broccoli growth. Preparation begins 2-3 weeks before planting:

1. Digging the soil – the soil is loosened to a depth of 30–35 cm, removing weed roots and plant debris.
2. Enrichment with organic matter – add humus or compost (5–6 kg per 1 m²) to improve the structure and increase fertility.
3. Optimizing acidity – broccoli grows best at a pH of 6.2–6.8. If the soil is acidic, add dolomite flour (400–500 g per 1 m²) or lime.
4. Mineral additives – before planting, it is recommended to add superphosphate (30–40 g/m²) and potassium salt (15–20 g/m²), providing a nutritional base for plants.
5. Soil disinfection - 10 days before planting, treat with Fitosporin or a solution of potassium permanganate to protect against fungal diseases.

Tip: To improve the soil structure, you can add vermiculite or coconut substrate, increasing its air permeability.

Sowing and planting seedlings

Growing broccoli begins with sowing seeds, which is done 30–40 days before planting in the ground:

1. Seed preparation: 12 hours before planting, they are soaked in warm water (+50°C), then kept in cool water (+10°C) to increase germination.
2. Sowing in containers – seeds are sown in cassettes or boxes with loose substrate, deepening them by 1–1.5 cm.
3. The optimal germination conditions are temperature +18…+22°C, moderate watering, protection from drafts.
4. Picking – 10–14 days after emergence, the seedlings are transplanted into separate pots with a capacity of 250–300 ml.
5. Hardening – a week before planting, the temperature is reduced to +10…+12°C, airing the plants daily.

Planting scheme in the greenhouse:

• Early varieties: 30x40 cm.
• Mid-season and late varieties: 40×50 cm.

Tip: Plant seedlings in cloudy weather or in the evening to minimize transplant stress.

Caring for broccoli in a greenhouse

Watering

• The first period (2 weeks after planting) – watering once every 2–3 days, 2–3 liters of water under the root.
• Period of active growth (formation of leaves and inflorescences) – 1–2 times a week, 5–7 l per plant.
• Head setting phase – the frequency of watering is increased, but it is important to avoid stagnant water.
• Before harvesting (10-14 days) – watering is reduced to increase the density of inflorescences.

Tip: The best method of watering is drip irrigation, it provides uniform moisture and prevents over-watering of the soil.

Top dressing

1. 3-4 leaf stage (10-14 days after planting):
   • Nitrogen fertilizers – urea (10 g/10 l), mullein infusion (1:10).
   • Additionally: foliar feeding with humates accelerates growth.
2. Formation of inflorescences (25–30 days after planting):
   • Phosphorus-potassium fertilizers – superphosphate (15 g/10 l), ash (200 g/m²).
   • Additionally: boric acid (1 g per 1 l of water) improves the quality of the heads.
3. Before harvesting, fertilizing is stopped so that broccoli does not accumulate nitrates.

Tip: To improve nutrition, you can use complex NPK fertilizers (10:10:10) every 3 weeks.

Protection from diseases and pests

Main diseases and their prevention

• Clubroot - removal of infected plants, liming of soil.
• Peronosporosis - treatment with Fitosporin or copper sulfate.
• Gray rot – decrease humidity, treatment with fungicides (Topaz, Fundazol).

Main pests and methods of control

• Cabbage aphid – treatment with garlic infusion or laundry soap solution.
• Cruciferous flea beetle - dusting with ash or tobacco dust.
• Cutworm caterpillars - hand collection, biological products (Lepidocid, Bitoxibacillin).

Advice: Practice crop rotation; do not grow broccoli in the same place more than once every 3 years.

Harvesting and storage

• Early varieties of broccoli are ready for harvesting in 60–80 days.
• Mid-season and late varieties – in 90–110 days.
• The heads are cut off when they reach 8–15 cm in diameter.
• After the first harvest, the side shoots continue to grow, providing additional yield.

Storage conditions

• Storage temperature: 0…+2°C.
• Humidity: 90–95%.
• Shelf life: 1–2 weeks in the refrigerator, up to 6 months when frozen.

Tip: To extend the shelf life of broccoli, you can blanch and freeze it.

Growing broccoli in a greenhouse

Growing broccoli in a greenhouse is an excellent solution for obtaining a stable and high-quality harvest. The main thing is to maintain an optimal temperature regime, properly feed and protect plants from pests.

Want to create ideal conditions for growing broccoli? Greenhouses from NovaTeplitsa provide reliable plant protection, create a stable microclimate and increase yields. Check out the models on our website and start growing broccoli with maximum efficiency!