Greenhouse Fertilizers - Buy from Manufacturer Dünger

Why Greenhouse Nutrition Differs from Open Ground

A greenhouse is a closed system. In open soil, plants receive nutrients from rain, organic matter breakdown and soil microorganisms. In a greenhouse, none of this exists. The plant is entirely dependent on what the grower provides.

This changes the rules of fertilization fundamentally:

• Frequency: every 7-14 days instead of 2-4 times per season. A greenhouse tomato at peak fruiting can exhaust its weekly nitrogen quota in 5 days.
• Completeness: all elements must be supplied artificially - including calcium, magnesium and micronutrients that field soil usually provides naturally.
• Salt accumulation: over-fertilization in greenhouses leads to salt buildup in the soil - plants wilt despite watering. Flush the soil with plain water (2-3x the normal watering volume) every 3-4 weeks.

Irrigation water pH: 5.5-6.5. At pH above 7.0, iron, manganese and boron become practically unavailable even when correctly added to the nutrient solution. Solution EC: seedlings 1.5-2.0 mS/cm; vegetative growth 2.0-2.5; active fruiting 2.5-3.5. At EC above 4.0: salt stress - flush the soil.

Tomatoes in the Greenhouse: Three Feeding Phases

The greenhouse tomato is the most demanding crop in terms of feeding precision. Wrong phase balance = poor fruit set, blossom-end rot or small fruit.

Phase 1 - Vegetative (transplant to first flower cluster): DÜNGER SKU 1 (N12-P15-K15-S15) - 20-25 g/10 L watering solution, every 10-14 days. N12 builds stem and leaves. P15 develops the root system. At transplanting, add DÜNGER SKU 29 (N6-P6-K3 + succinic acid) 50 ml/10 L: succinic acid relieves transplant stress and accelerates rooting.

Phase 2 - Flowering and fruit set: DÜNGER SKU 1 (10-15 g/10 L) + calcium nitrate 10-15 g/10 L separately. Calcium Ca is the key element of this phase. Blossom-end rot (BER) - dark leathery patch on the base of fruit - is not a disease; it is calcium deficiency in the developing fruit. Prevention: calcium nitrate every 10-14 days, consistent watering without drying out. Foliar calcium chloride 5 g/10 L at first symptoms.

Phase 3 - Active fruiting: DÜNGER SKU 19 (P23-K30) - 20-25 g/10 L, every 10 days. Zero nitrogen: excess N at this stage produces lush green mass and small, acidic fruit. K30 accumulates sugars in fruit, builds firm flesh texture and extends shelf life.

Cucumbers in the Greenhouse: Fast Growth Needs Frequent Feeding

Cucumbers grow and fruit much faster than tomatoes: 35-45 days from transplant to first fruit. This means feeding every 7-10 days.

Vegetative phase (until first fruit set): DÜNGER SKU 1 - 20 g/10 L every 10 days. Cucumbers are sensitive to concentrated solutions: do not exceed the dose - feed less and more often.

Fruiting phase: DÜNGER SKU 19 - 20 g/10 L every 7-10 days. During fruiting cucumbers consume K and P more intensively than N. K maintains fruit turgor, crispness and even seed placement.

Most common cucumber problems in the greenhouse:

• Lower leaf yellowing between green veins - magnesium (Mg) deficiency. Foliar magnesium sulfate 20 g/10 L twice.
• Bitter fruit - stress from inconsistent watering or overheating, not a nutrition issue. Normalize watering, ventilate the greenhouse.
• 'Bear's paw' (deformed fruit) - boron (B) deficiency. Foliar boric acid 1 g/10 L at flowering.

Peppers and Greens in the Greenhouse: Calcium and Precise Dosing

Sweet peppers: establish slowly after transplanting. First week after planting - DÜNGER SKU 29 (50 ml/10 L) with no other fertilizers: succinic acid stimulates root growth. From the second week - SKU 1 (15 g/10 L) every 10-14 days. At first fruits - SKU 19 (20 g/10 L). Calcium nitrate 10 g/10 L every 2 weeks throughout the season: peppers are even more sensitive to Ca deficiency than tomatoes - BER in peppers appears as a dark sunken patch at the fruit tip.

Greens (lettuce, basil, dill, parsley): need only nitrogen-phosphorus feeding - SKU 1 at half dose (10 g/10 L) every 10-14 days. Excess K and P are not needed for greens: these crops are harvested before fruiting. Important: do not exceed EC 2.5 for lettuce and herbs - they are more salt-sensitive than fruiting crops.

pH and EC Control: The Two Parameters That Determine Everything in a Greenhouse

A greenhouse grower who does not measure the pH and EC of their irrigation solution is like a doctor diagnosing without tests. Two simple meters - a pH meter and an EC meter - prevent 80% of greenhouse nutrition problems.

Irrigation solution pH (5.5-6.5):

• At pH above 7.0: iron, manganese, boron and zinc become unavailable even with the correct fertilizer solution. Leaves yellow despite feeding - classic symptom of incorrect pH.
• At pH below 5.5: roots are damaged; Ca and Mg uptake is impaired.
• How to correct: add phosphoric acid to the solution to lower pH, or baking soda to raise it. Check before every watering.

Irrigation solution EC:

At EC above 4.0 mS/cm: flush with plain water at 2-3x the normal watering volume. Salts exit in drainage. After flushing, resume feeding from the lower EC limit.

Micronutrients in the Greenhouse: Why They Matter More Than in Open Ground

Open soil has a natural buffer: soil microorganisms mobilize micronutrients from mineral particles. In a greenhouse that buffer is absent. Every micronutrient must come from the nutrient solution.

• Iron Fe: interveinal chlorosis on young leaves. Foliar chelated iron 3-5 g/10 L twice, 7 days apart. Most common at pH above 6.5.
• Magnesium Mg: interveinal chlorosis on older leaves. Foliar magnesium sulfate 20 g/10 L twice.
• Calcium Ca: blossom-end rot (BER) in tomatoes and peppers, tip burn in lettuce. Calcium nitrate 10-15 g/10 L root feeding every 10-14 days, regardless of other fertilizers.
• Boron B: poor fruit set, deformed ovaries. Boric acid 1 g/10 L foliar at flowering.

Deliver DÜNGER greenhouse fertilizers across Ukraine: Kyiv, Kharkiv, Dnipro, Odesa, Zaporizhzhia, Lviv, Kryvyi Rih, Vinnytsia, Poltava, Mykolaiv, Chernihiv, Cherkasy, Zhytomyr, Sumy, Rivne, Ternopil, Khmelnytskyi, Ivano-Frankivsk, Lutsk, Uzhhorod, Chernivtsi and other cities of Ukraine.