Knowledge Base

Why Pollination Matters in a GreenhouseUnlike field-grown tomatoes, greenhouse tomatoes can't rely on wind or outdoor pollinators to transfer pollen. Without adequate pollination, flowers drop and fruit set fails — directly impacting your yield and revenue. Understanding how to manage pollination in a controlled environment is one of the most important skills for any greenhouse grower.How Tomato Pollination WorksTomatoes are self-fertile, meaning each flower contains both male and female parts. Pollen is released from the anther cone when the flower is vibrated at the right frequency — a process naturally triggered by bumblebees or wind outdoors. In a greenhouse, you need to replicate this vibration artificially.Pollination Methods1. Electric Pollination WandsThe most common commercial method. A battery-powered wand is touched to the back of each open flower cluster (truss) for 1–2 seconds, causing the anther cone to vibrate and release pollen. This should be done every 1–3 days during the flowering period, ideally between 10 AM and 2 PM when temperatures and humidity are optimal.2. Bumblebee ColoniesMany large-scale greenhouse operations introduce commercial bumblebee hives (typically Bombus terrestris) for natural pollination. Bees are highly effective and reduce labor, but require careful management — including monitoring hive health, avoiding pesticide conflicts, and replacing colonies every 6–8 weeks.3. Manual ShakingFor small operations or trial plantings, gently shaking individual trusses or the plant support wire can transfer enough pollen for adequate fruit set. Less consistent than wands or bees, but useful as a backup method.Optimal Conditions for PollinationPollination success is highly dependent on environmental conditions: Temperature: 65–75°F (18–24°C) during the day. Temperatures above 85°F (29°C) can cause pollen sterility. Relative Humidity: 60–70%. Too dry and pollen won't stick; too humid and it clumps and won't release. Light: Adequate light (DLI of 20–30 mol/m²/day) supports strong flower development and viable pollen. Timing: Pollinate during the warmest, brightest part of the day for best results. Signs of Poor PollinationWatch for these indicators that pollination is failing: Flower drop without fruit set Small, misshapen, or hollow fruit (catfacing) Uneven ripening across the truss Low fruit count per truss relative to variety expectations Variety ConsiderationsSome tomato varieties are more forgiving of suboptimal pollination conditions than others. Indeterminate greenhouse varieties bred for controlled environments — such as many of the varieties in the Paramount Seeds tomato catalog — are selected for strong fruit set and consistent performance under greenhouse conditions.Key TakeawaysConsistent, well-timed pollination is foundational to greenhouse tomato productivity. Whether you use electric wands, bumblebees, or manual methods, the goal is the same: reliable vibration of open flowers during peak conditions, repeated every 1–3 days throughout the flowering cycle. Pair good pollination practice with proper pruning, climate control, and variety selection for the best results.Disclaimer: The information in this article is intended for educational purposes only. Always consult with a qualified agronomist or extension specialist before making changes to your growing practices. Results may vary based on variety, environment, and management conditions.

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.

Greenhouse cucumbers are one of the most rewarding crops to grow — but getting germination right is the foundation of a successful crop. Whether you're working with treated or untreated seed, the right environment and technique will give you fast, uniform sprouting and strong transplants. Here's a step-by-step guide to getting it right. What You'll Need Greenhouse cucumber seed (treated or untreated) Rockwool cubes or coco coir propagation plugs Seedling tray with humidity dome pH-balanced water (pH 5.8–6.2) Bottom heat mat Grow lights (LED or HPS) Thermometer and hygrometer Step 1: Pre-Soak Your Growing Medium Soak rockwool cubes in pH-adjusted water (pH 5.8–6.0) for at least 30 minutes before sowing. Rockwool is naturally alkaline — skipping this step can cause nutrient issues right from the start. Shake out excess water gently. The medium should be evenly moist, not dripping wet. Step 2: Set Up Your Germination Environment Before sowing, get your environment dialed in. Cucumber seeds need warmth to germinate reliably: Substrate temperature: 77–86°F (25–30°C) — use a bottom heat mat Air temperature: 72–77°F (22–25°C) Relative humidity: 90–95% under the dome Cold conditions below 60°F will cause slow, uneven germination or seed rot. Step 3: Sow the Seeds Place one seed per plug, about ½ inch (1–1.5 cm) deep, with the pointed end facing down. Cover trays with a humidity dome immediately after sowing to lock in moisture and heat. Under optimal greenhouse conditions, expect to see radicles emerging in 2–4 days. Step 4: Maintain Moisture Check trays at least twice daily. The growing medium must stay consistently moist — if it dries out, germination rates will drop. Mist lightly if the surface looks dry, but avoid waterlogging, which promotes rot. Step 5: Remove the Dome at Emergence As soon as the first cotyledons appear, remove the humidity dome. Leaving it on too long in a warm greenhouse creates the perfect conditions for damping-off and fungal issues. Increase airflow gradually to harden seedlings to greenhouse conditions. Step 6: Provide Light Once seedlings emerge, move them under your grow lights immediately. Cucumbers need 16–18 hours of light per day at 200–400 µmol/m²/s to develop compact, vigorous transplants. Insufficient light leads to stretchy, weak seedlings. Step 7: Transplant at the Right Time Seedlings are ready to transplant when they have 1–2 true leaves and a well-developed root system — typically 10–14 days after sowing. Don't let them become root-bound in the plug; transplant shock is harder to recover from at that stage. Tips for Better Germination Rates Use bottom heat — substrate temperature matters more than air temperature for cucumber germination Don't overwater — moist, not wet, is the goal at every stage Use sterile media and clean trays — reusing old trays without sanitizing is a common source of Pythium Label your trays — if trialing multiple varieties, keep them organized from day one Troubleshooting No germination after 5 days — Check substrate temperature (too cold?) and moisture (dried out?) Leggy seedlings — Lights too far away or too few hours; move lights closer and increase duration Damping-off or rot — Humidity dome left on too long or overwatering; improve airflow and reduce moisture Uneven germination — Temperature fluctuations; check heat mat consistency across the tray Ready to Grow? Browse our popular greenhouse cucumber varieties — bred for high performance, disease resistance, and consistent yields in controlled environments: Verdon F1 Long Dutch Cucumber (Treated) Bologna F1 Long Dutch Cucumber Georgia F1 Long Dutch Cucumber (Treated) Excelsior F1 Pickling Cucumber (Untreated) Corinto F1 Slicer Cucumber Have questions? Get in touch with the Paramount Seeds team — we're happy to help you find the right variety and get your crop off to a great start.

A practical guide to fertilizing greenhouse seedlings — covering when to start, what nutrients matter most, and how to avoid common mistakes. Includes guidance for key crops grown from Paramount Seeds varieties.

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

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.

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