Knowledge Base

Picking the right seed variety can make or break a season. Learn how AI tools are helping greenhouse growers make smarter, data-backed variety decisions — matched to your environment, your market, and your goals.

Not sure whether to grow indeterminate or determinate tomatoes? This guide breaks down the key differences in growth habit, harvest timing, and best use cases to help you choose the right variety for your operation.

If you've read a seed catalog recently, you've likely seen a Brix value listed alongside variety specifications. It's a common quality metric in greenhouse tomato and specialty crop production — but what does it actually measure, and why does it matter for your operation?What Is Brix?Brix (°Bx) is a measurement of the dissolved sugar content in a liquid, expressed as a percentage by weight. In the context of fruit and vegetable production, it's used as a proxy for sweetness and overall flavor intensity. A tomato with a Brix of 8 has approximately 8 grams of dissolved sugars per 100 grams of juice.The measurement is taken with a refractometer — a simple handheld optical instrument that reads how light bends through a liquid sample. A drop of juice on the prism gives an instant reading.Brix in Greenhouse CropsBrix values vary significantly by crop type and variety: Crop Typical Brix Range Notes Cherry tomato 7–10 °Bx Higher Brix; flavor is a key selling point Beefsteak tomato 4–6 °Bx Lower Brix; yield and size prioritized Cluster tomato 5–7 °Bx Balanced flavor and yield Mini cucumber 3–5 °Bx Mild, fresh flavor profile Bell pepper (red) 5–8 °Bx Increases as fruit ripens from green to red Papaya 10–14 °Bx High natural sugar content; Brix is a key quality indicator for export and premium markets Lettuce 3–5 °Bx Lower range; freshness and texture matter more Disclaimer: Brix ranges listed are approximate and vary by growing conditions, season, and variety. Always refer to individual variety specifications for precise data.Cherry and specialty tomatoes command higher Brix targets because flavor is a primary purchase driver. Beefsteak and cluster types prioritize yield, size, and shelf life — Brix is secondary. Papaya is among the highest-Brix crops in greenhouse and tropical production, where sugar content is a direct quality and marketability indicator.What Affects Brix in the Greenhouse?Brix is not fixed by genetics alone — cultural practices have a significant influence: EC (Electrical Conductivity) — Higher EC in the nutrient solution stresses the plant slightly, concentrating sugars in the fruit. Raising EC is the most direct lever for increasing Brix, but it comes at a yield cost — smaller fruit and reduced total output. Light levels — Higher light drives more photosynthesis and sugar production. Low-light periods (winter) typically produce lower-Brix fruit. Irrigation management — Mild water stress at key growth stages concentrates sugars. Overwatering dilutes Brix. Temperature — Cool nights slow respiration and help retain sugars in the fruit. Harvest timing — Brix increases as fruit ripens. Harvesting too early reduces flavor; harvesting at full color maximizes Brix. Variety selection — Genetics set the ceiling. High-Brix varieties like cherry tomatoes and papaya are bred for flavor; selecting the right variety is the foundation. Brix and MarketabilityFor direct-to-consumer and premium foodservice channels, Brix is increasingly used as a quality specification. Some buyers set minimum Brix thresholds — particularly for cherry tomatoes, specialty varieties, and papaya — as part of their procurement standards. Knowing your crop's Brix profile helps you position product accurately and meet buyer expectations.For wholesale and retail supply, consistent Brix within a defined range matters as much as hitting a high number — buyers want predictability across deliveries.Using Brix as a Management ToolBeyond marketing, Brix monitoring is a practical crop management tool. Regular refractometer readings through the season help you: Track the impact of EC and irrigation adjustments on fruit quality Identify stress events (disease, root issues, climate swings) that affect sugar accumulation Benchmark variety performance across your facility A refractometer costs under $50 and takes seconds to use — it's one of the highest-value diagnostic tools in a greenhouse operation.Related ReadingMaxifort vs. DR0141TX: Choosing the Right Tomato Rootstock for Your GreenhouseShop High-Brix Varieties Favorita F1 Cherry Tomato Limoncito F1 Cherry Tomato Tomagellow F1 Cherry Tomato Amsterdam F1 Cherry Tomato Red Nemesis F1 Papaya Formosa F1 Papaya Linda F1 Papaya Improved Solo Sunrise F1 Papaya Red Matador F1 Papaya

Proper pruning is one of the most important crop management practices for indeterminate greenhouse tomatoes. Learn the techniques that keep your plants productive, healthy, and manageable all season long.

Pruning is essential for productive, healthy greenhouse cucumber crops. This guide covers the correct techniques for both long English and mini cucumber varieties, and explains the key differences between them.

A clear breakdown of F1 hybrid vs open-pollinated seeds for greenhouse growers — covering hybrid vigor, uniformity, disease resistance, seed saving, and real variety examples from the Paramount Seeds catalog.

Sweet pepper (Capsicum annuum) and the increasingly popular mini pepper can be a great choice for greenhouse growers. This guide covers the full production cycle from variety selection through harvest. Variety Selection Variety choice is the single most important decision in a pepper program. Key selection criteria include: Fruit type — standard block (California type), elongated (lamuyo), or mini pepper. Each has distinct market requirements for size, wall thickness, and color. Color — red, yellow, and orange are the primary commercial colors. Green peppers are immature fruit of any color variety. Red varieties typically have the longest production cycle; yellow and orange are intermediate. Disease resistance — prioritize resistance to Phytophthora capsici (Pc), Tobacco mosaic virus (Tm:0,1,2), Tomato spotted wilt virus (TSWV), and Leveillula taurica powdery mildew (Lv) Yield and fruit set — evaluate fruit set under low light and high temperature conditions relevant to your production season Shelf life and firmness — critical for export and long-distance distribution channels Paramount Seeds Greenhouse Pepper Varieties The following varieties are available from Paramount Seeds. Click any variety name to view full details and order. Red Bell Pepper Variety Key Notes Disease Resistance Sprinter F1 Blocky red; not sensitive to BER or russetting Tm 0–3 Garnet F1 Blocky red; highly resistant L4 L4, IR: TSWV 0 Zamboni Large very uniform fruits Tm2 Yellow Bell Pepper Variety Key Notes Disease Resistance Berkeley F1 Blocky yellow; avg 225–245g Tm 0–3 Bachata F1 Strong balanced plant; generative steer Tm 0–3 Orange Bell Pepper Variety Key Notes Disease Resistance Milena F1 Early maturing orange blocky HR: PVY 0–1, Tm 0–3; IR: TSWV 0 Orangery F1 High yield; good quality fruits Tm 0–3 Mini Pepper Variety Color Key Notes Disease Resistance Lunchbox Red Red Sweet; selected for snacks/clamshells — Trirosso F1 Red Sweet; self-pollinating Tm 2 Pepper Rootstock Variety Key Notes Disease Resistance Foundation F1 (RZ 52-03) Strong root system; nematode resistant Tm 0, Nematode Bedrock F1 (RZ 52-04) Generative effect on graft; nematode resistant Tm 3, Nematode, IR: Phytophthora, TSWV Mini Pepper Varieties Mini peppers (typically 40–70g fruit weight) have grown significantly in market share due to their snacking convenience, sweetness, and visual appeal in mixed-color retail packs. Key considerations for mini pepper production: Higher fruit count per plant than standard block types Shorter days to first harvest Typically harvested at the immature green stage or allowed to color for premium pricing Require careful grading for size uniformity in retail pack formats Well suited to high-wire long-season production systems Browse our Greenhouse Pepper varieties including block and mini types. Propagation and Transplanting Seeding and Germination Sow into 128 or 200-cell plug trays using a fine-textured germination mix Germination temperature: 25–28°C (77–82°F) Days to germination: 7–10 days Pelleted seed is strongly recommended for precision seeding and uniform germination Maintain high humidity during germination; reduce after emergence to prevent damping-off Propagation Period Total propagation time from seeding to transplant: 8–10 weeks Grow-on temperature: 20–22°C day / 18–20°C night Transplant at the 6–8 true leaf stage, before flower buds are visible, to avoid transplant shock affecting early fruit set Harden plants gradually before transplanting into the production greenhouse Transplanting Plant spacing: 2.5–3.0 plants/m² for standard block types; 3.0–3.5 plants/m² for mini peppers Row configuration: typically double rows on raised substrate slabs (rockwool, coco coir, or perlite) Transplant into pre-wetted substrate; avoid planting too deep Maintain substrate temperature above 18°C at transplanting to encourage rapid root establishment Plant Training and Pruning Initial Training Pepper plants naturally fork at the first flower (the crown bud). The standard training system for greenhouse peppers involves: Crown bud removal — remove the first flower at the fork to direct energy into vegetative growth and establish a strong plant framework Two-stem training — allow two main stems to develop from the first fork; tie each stem to a separate support string Subsequent branching — at each subsequent fork, retain one stem and remove the other (or allow both in high-density systems) Ongoing Pruning Remove all shoots below the first fork to maintain an open, well-ventilated plant base Remove leaves showing disease symptoms immediately Leaf pruning in the lower canopy improves airflow and reduces Botrytis pressure — remove lower leaves progressively as the crop develops For mini peppers, a higher stem density is often maintained to maximize fruit count per m² High-Wire Production Long-season greenhouse pepper production uses a high-wire system where plants are trained vertically and lowered progressively as they grow, similar to tomato production. This allows continuous production from a single planting for 9–12 months or longer. Climate Management Temperature Day temperature: 22–26°C (72–79°F) during fruit development; reduce to 20–22°C during coloring Night temperature: 18–20°C (64–68°F) Minimum temperature: Do not allow temperatures below 15°C — chilling causes fruit deformation and blossom drop Maximum temperature: Above 32°C, pollen viability drops sharply and fruit set fails. Ventilate aggressively and use shade screens in summer. DIF (day-night temperature difference): A positive DIF (warmer days than nights) promotes compact, sturdy growth Humidity and VPD Target relative humidity: 65–75% Target VPD: 0.8–1.2 kPa during the day High humidity (>85%) promotes Botrytis and powdery mildew; low humidity (<50%) causes blossom drop and tip burn Maintain horizontal airflow fans throughout the crop to prevent humidity stratification CO₂ Enrichment Target CO₂: 800–1,000 ppm during daylight hours with vents closed CO₂ enrichment significantly improves fruit set, fruit size, and yield in closed or semi-closed greenhouse systems Reduce or stop enrichment when vents are open to avoid waste Light Optimal DLI: 25–30 mol/m²/day Supplemental lighting is beneficial in winter production at northern latitudes Maximum photoperiod: 16–18 hours — some varieties are photoperiod-sensitive; confirm before setting lighting schedules Irrigation and Nutrition Irrigation Drip irrigation directly to the substrate slab is standard in soilless greenhouse pepper production Irrigation frequency and volume are managed based on radiation sum (typically 100–150 J/cm² per irrigation event) Maintain substrate water content at 60–80% field capacity; avoid waterlogging which promotes Phytophthora First irrigation of the day: 1–2 hours after sunrise; last irrigation: 1–2 hours before sunset Target drain percentage: 20–30% to prevent salt accumulation in the substrate Nutrition Pepper has moderate to high nutrient requirements. Key parameters for a standard pepper nutrient solution: EC (electrical conductivity): 2.5–3.5 mS/cm in the root zone; higher EC improves fruit quality and shelf life but reduces yield pH: 5.5–6.0 in the root zone Key macronutrients: Nitrogen (NO₃⁻ dominant), Potassium (high K:N ratio during fruiting), Calcium (critical for cell wall integrity and blossom end rot prevention), Magnesium Key micronutrients: Iron, Manganese, Zinc, Boron (important for pollen viability and fruit set) Increase K and Ca during heavy fruiting periods; reduce N to avoid excessive vegetative growth Pollination Pepper flowers are self-fertile but require vibration to release pollen effectively. In greenhouse production, pollination is typically achieved by: Bumblebees (Bombus terrestris) — the most effective and widely used pollination method in commercial greenhouse pepper production. Bumblebee hives are introduced at first flower and replaced every 6–8 weeks. Electric vibrators (pollination wands) — used to manually vibrate flower clusters; labor-intensive but effective in smaller operations or when bees are unavailable Air movement — horizontal airflow fans contribute to passive pollen dispersal but are insufficient as the sole pollination method Poor pollination is one of the most common causes of misshapen fruit, blossom drop, and low fruit set in greenhouse peppers. Ensure bumblebee hives are active and healthy throughout the production season. Fruit Development and Coloring Pepper fruit development follows a predictable timeline from fruit set to harvest: Days from fruit set to green harvest: 45–60 days depending on temperature and variety Days from green to full color (red/yellow/orange): an additional 3–4 weeks Mini peppers: reach harvest size faster — typically 35–45 days from fruit set to green harvest Coloring is temperature-sensitive. Optimal coloring temperature is 18–22°C — high temperatures (>28°C) slow or prevent color development. In summer production, night cooling or shade management may be needed to achieve full color. Harvest Harvest Timing Harvest standard block peppers at full color (red, yellow, or orange) for maximum market value Green harvest is possible for specific markets but commands lower prices Mini peppers are harvested at full size — either green or at full color depending on market specification Harvest frequency: 2–3 times per week in peak production Harvest Technique Cut fruit with a clean, sharp knife or scissors — do not pull, which can damage the plant and create entry points for disease Leave a short stem (1–2cm) attached to the fruit to extend shelf life Handle fruit carefully to avoid bruising — pepper skin is thin and bruises easily Harvest into clean, ventilated containers; avoid stacking more than 2–3 layers deep Post-Harvest Handling Cool fruit to 8–10°C as quickly as possible after harvest Do not store below 7°C — chilling injury causes surface pitting and accelerated decay Target storage humidity: 90–95% Shelf life at optimal storage: 2–3 weeks for standard block types; 1–2 weeks for mini peppers Common Production Challenges Blossom drop — caused by temperature extremes, low humidity, poor pollination, or excessive nitrogen. Review climate and pollination management. Misshapen fruit — typically caused by poor pollination or boron deficiency. Ensure bumblebee activity and check boron levels in the nutrient solution. Blossom end rot — calcium deficiency at the fruit tip; caused by irregular irrigation, high EC, or poor calcium uptake. Maintain consistent irrigation and adequate calcium supply. Sunscald — white or bleached patches on fruit exposed to direct intense light. Use shade screens in summer and maintain adequate leaf cover over developing fruit. Phytophthora root rot — avoid waterlogging; select resistant varieties; maintain substrate hygiene between crops. Browse our full range of Greenhouse Pepper varieties — including standard block, lamuyo, and mini pepper types with strong disease resistance packages. The Bottom Line Greenhouse sweet pepper production rewards attention to detail at every stage — from variety selection and propagation through climate management, nutrition, and harvest. Mini peppers add a high-value, fast-cycling option to any pepper program, with strong retail demand and efficient use of greenhouse space. Have questions about variety selection, production systems, or crop management for your greenhouse pepper program? Contact the Paramount Seeds team — we're here to help.

Disease resistance codes on seed packets can be confusing. This guide explains the standard HR and IR resistance designations and lists the key resistance codes for greenhouse tomato, cucumber, lettuce, and pepper crops available from Paramount Seeds.