Channeling my best baseball peanut salesman.

How can anyone or better yet why would anyone spend time on an article about greenhouse doors? I mean it is pretty straight forward. Right? Basically, yes but as with any accessory of a greenhouse there needs to be thought put into it for it to be useful and worthwhile.

You’re building a greenhouse and you come across the line item of doors in the design phase. You need to get in and out of the greenhouse, equipment is coming in and out, possibly vehicles need access, the point is there is the plan for now and a need to plan for the future.This is not a very in depth topic, but look out 5 years and think what will I be growing? Will your access to the greenhouse need to change? Be sure to plan around this.

Why is watering so important?

Crop quality is closely tied to plant irrigation. Both the amount and the timing of watering are important, and should be carefully planned and monitored. Next to light, watering is the next most critical production factor.

What are the effects of under watering?

Even mild under‐watering causes photosynthesis to shut down. When plants lack adequate water for uptake, all aspects of plant development become stunted: leaves, fruit, flowers, stem growth are all affected. Depending on the stage of plant and degree of water stress, this stunting can have a permanent effect on the plant. Severe under‐watering results in a burned appearance on the foliage and flowers.

What are the effects of overwatering?

Excessive watering can be as or more damaging to the crop as under‐watering. The soil environment which is conducive to plant growth contains both readily available water and air. When soil is over‐watered, the air is ‘driven out’ of the soil, and the roots are unable to survive very long in this condition. If persistent, the roots die, and the plants are unable to uptake the water and nutrients they need. A wet root environment also...

What is ventilation?

Ventilation is the exchange of air between the inside and outside of the greenhouse. It is used to remove heat from solar radiation, to replenish carbon dioxide and to help control the levels of relative humidity.

What is a ventilation rate?

The ventilation rate refers to the amount of ventilation per unit area. It is measured as cubic feet of air‐ per‐minute per square foot of greenhouse floor area (CFM per square foot) because the heat load derives from solar radiation and is directly proportional to floor area.

What is the difference between natural and mechanical ventilation?

Natural ventilation results from the wind and stack action from ventilator sashes. Mechanical ventilation is created by electric fans and related equipment.

What does cooling refer to?

Cooling consists of reducing the air temperature by the evaporation of water into the air‐stream. The system that does this and moves the cooled air through the greenhouse and exhausts the warmed air is the cooling system.

What is circulation?

Circulation is the movement and mixing of air in a greenhouse to promote uniformity in temperature and humidity and to provide proper...

What are the advantages of insect screening?

Properly installed insect screening restricts the entry of insects and pests and reduces exposure to pesticides.

What are the disadvantages of insect screening?

While manageable, the disadvantages of insect screening includes increased sizing and fastening problems, less ventilation, reduced access to the greenhouse, and added maintenance. In addition screens can keep insects in as well as out.

What are the negative effects screens have on airflow?

Screens with small holes are more effective in excluding pests but are more resistant to airflow. A screen with too much restriction of airflow can cause higher static pressure drops, inadequate air exchange, increased energy consumption by the fans, excessive wear on the fan motors, and higher greenhouse temperatures.

THE BASICS OF CONTROL

How does heat loss occur?

Heat loss occurs from a greenhouse structure whenever the interior temperature exceeds the exterior temperature. The rate at which it occurs is affected primarily by the efficiency of the covering materials (glazings) installed on each surface (roof, side walls, and end walls). The most commonly used covering materials all have published heat transfer factors called “U” factors that provide a means of calculating their impact on heat loss in different scenarios.

What is the “U” factor?

“U” factors are the inverse of the commonly used “R” factors, where “U” = 1 / “R”. The lower the “U” factor, the less ability your glazing material has to transfer heat, therefore, the lower the heat loss.

This article is brought to you by the NGMA

Ultra-Niche Crops are defined as exceptionally high-value crops that can provide a significant source of income to the farmer while using minimal land area.

Winter lettuce is a crop that is seeded or transplanted in a high tunnel or other protected structure after the traditional planting season. Winter lettuce planting takes place from late summer through the fall, and lettuce is harvested during the cooler months. Many types of lettuce are suitable for winter production in high tunnels, including Butterhead, Romaine, and baby leaf types. It is important to understand the growth needs of a winter lettuce crop, such as temperature requirements, and soil moisture. Producing winter lettuce in high tunnels provides a lower-input option to traditional heated greenhouse production. Growing winter lettuce in a high tunnel is a way to extend the season and increase revenue while maintaining your customer base through the winter months.

It is easy to get lost in the details of how a greenhouse functions or troubleshooting an equipment failure. Helping customers on specific projects is the day to day but the overall function of Stuppy is wider and deeper. In short we design, manufacture and construct greenhouses and growing systems, but this leaves out how and why.

It’s ironic, schools and commercial growers come to us to get questions answered and intern get asked more questions than they had for us. This really is the fundamental approach we take. We make sure to understand what is needing to be done i.e. new greenhouse, renovation etc. but deeper than this is understanding why the greenhouse project is being completed. This is accomplished by asking a lot of questions. These questions and the answers are what we base our greenhouse design around. Our goal is to produce a greenhouse that functions exactly as you had envisioned and need it to perform.

A DYNAMIC ENVIRONMENT

Greenhouse environments present unique challenges to good control. Temperature changes occur rapidly and vary widely depending on solar radiation levels, outside temperatures and humidity levels, wind speed and direction, the amount of plant material in the greenhouse, watering routines, etc. Proper control of this dynamic environment is indeed challenging, but the benefits of good control far exceed the costs.