Knowledge Base

A practical guide to papaya plant sex types — male, female, and hermaphrodite — covering how to identify each, expected seed ratios, and why managing sex expression is critical for commercial papaya production.

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.

ToBRFV is a serious and persistent threat, but it is manageable with the right combination of resistant varieties and disciplined hygiene practices. At Paramount Seeds, we are committed to providing growers with the best tools to protect their crops

Getting lighting right is one of the highest-leverage decisions a greenhouse grower can make. This guide covers the fundamentals of artificial lighting, the key technologies available, and how to apply them to your specific crops.

A concise guide to the three most common water sources in greenhouse production — well water, city water, and reverse osmosis — covering key characteristics, advantages, limitations, and how each affects crop nutrition and performance.

Thinking Outside the Tomato: Four Crops Worth Trialing in Your Greenhouse Greenhouse production has long centered on tomatoes, cucumbers, and peppers — and for good reason. But growers looking to differentiate their offerings and capture premium market segments are increasingly turning to crops like squash, melon, eggplant, and sunflower. Here's what to know before you trial them. Varieties Available from Paramount Seeds Crop Featured Variety Type Squash Squash Yellowfin F1 Summer squash, treated seed Melon Tirreno Cantaloupe Melon F1 Cantaloupe Eggplant Angela F1 Eggplant Standard eggplant Sunflower Dorit F1 Sunflower Cut flower, single-stem Squash Summer squash varieties perform well under greenhouse conditions and can be harvested in as little as 45–55 days from transplant. Greenhouse production extends the season significantly and allows for tighter quality control compared to field-grown crops. Key considerations: Squash requires pollination, which means either introducing pollinators (bumblebees work well in enclosed structures) or hand-pollinating. Vine management is also important — trellising keeps plants productive and reduces disease pressure. Look for compact or bush-type varieties suited to high-density planting. Melon Greenhouse melons — including cantaloupe, honeydew, and specialty types like Charentais — command strong prices at farmers markets and in specialty retail. The controlled environment eliminates many of the weather risks that make field melon production unpredictable. Key considerations: Melons are heat-loving and require consistent temperatures above 65°F at night. Like squash, they need pollination support. Fruit must be supported with netting as it develops on the vine. Harvest timing is critical — brix testing helps ensure peak sweetness before picking. Eggplant Eggplant is well-suited to greenhouse production and benefits greatly from the extended season and pest management that a controlled environment provides. Specialty varieties — Japanese, Italian, and white eggplant — are particularly attractive to restaurant buyers and specialty grocers. Key considerations: Eggplant is a long-season crop (70–85 days to first harvest) but continues producing for months once established. It prefers warm temperatures and consistent moisture. Trellising is recommended for indeterminate types. Thrips and spider mites are the primary pest concerns in greenhouse settings. Sunflower Cut sunflowers are a high-margin, fast-turn crop that fits naturally into a greenhouse operation with available bench or floor space. Single-stem varieties can be ready to harvest in 55–70 days and are in consistent demand from florists, farmers markets, and direct buyers. Key considerations: Sunflowers are day-length sensitive — supplemental lighting may be needed to manage flowering timing in winter months. Succession planting every 2–3 weeks ensures a continuous supply. Unlike the vegetable crops above, sunflowers don't require pollination management and have minimal pest pressure in greenhouse environments. Evaluating Fit for Your Operation Space and infrastructure: Squash and melon are vining crops that need vertical space and strong trellis systems. Eggplant and sunflower are more compact and easier to integrate into existing bench layouts. Market readiness: Confirm buyer interest before scaling. Chefs, florists, and specialty retailers are natural first contacts for these crops. Trial scale: Start with one bench or a small block of each crop. Track days to harvest, yield per plant, labor input, and sale price to build a reliable cost-of-production model. These four crops won't replace your core production — but trialed thoughtfully, they can add meaningful revenue, reduce seasonal gaps, and give your brand a point of difference in competitive markets.

Sanitation is the foundation of every successful greenhouse IPM program. Learn why thorough cleaning between crop cycles protects your biological control investments, grafted crops, and bottom line.

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.

Ever wondered how seed is pelleted or what and why it is used? Let us break down the step-by-step pelleting process — from seed grading to coating, sizing, drying, and quality testing — and what it means for germination performance.

A concise guide to understanding and preventing tipburn in hydroponic lettuce — covering causes, environmental controls, calcium management, and variety selection for commercial greenhouse growers.

A clear breakdown of GMO vs Non-GMO seeds for greenhouse growers — including what GMOs are, why they are not used in commercial greenhouse vegetable production, and how Paramount Seeds varieties are bred conventionally for performance and disease resistance.

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.

Controlled-environment agriculture offers three distinct soilless production systems — hydroponics, aquaponics, and aeroponics. Each has its own infrastructure requirements, operating costs, and crop performance profile. Here's how to choose the right one for your operation.