What are the considerations for growing over the summer?

Ventilation, excess heat, making sure roll up sides are critter proof

One of the critically important things that each gardener/grower needs to know is the temperature threshold of each plant.

This is the temperature at which a plant will stop growing and an even higher temperature at which a plant will die.

When a plant has passed the threshold where it stops growing, it will take some time to recover and start growing again.

This is why proper ventilation is so vitally important. On a sunny day, proper ventilation is defined as one air change per minute. You must know the volume of air in your greenhouse and have your ventilation method capable of moving that much air.

A forced ventilation system is the simplest to set up and control since it is thermostatically controlled. The up front and operating cost are significant. Each exhaust fan has a cubic feet per minute (cfm) rating which must be equal or greater than the air volume of the building. A forced ventilation system also has a motorized louvre which will open each time the fan turns on.

On a shorter structure that is facing into the wind, there is the option of ventilating through the doors and windows. This is an economical system but the hardest to control.

Adding roll up sides to a structure has the capacity of moving a lot of air as long as there is air movement around the greenhouse.

This is why it is a good idea to install a window as high on each end as possible. Since warm air rises, this will create a “chimney” effect on a calm day. The down side of roll up sides is the potential for draft across the floor and the fact that you have to be there to open and close the system. You may need to put up mesh to deter uninvited guests.

In addition to changing the air in the greenhouse, it is also important to circulate the air horizontally. Stagnant air pockets invite disease problems. There is not a prescribed rate to move the air, it is just important to keep it moving.

A proper watering system would not be considered as a part of making a greenhouse more efficient but it must be remembered that a greenhouse will increase the water needs of all of the plants.

A final consideration for growing over the summer is the potential need for shade. Most vegetables are good for full sun, all the time, but it is important to remember that this does not apply to all plants.

Wishing you a productive growing season!

We hope you are finding value in this series of posts, helping you prepare for your new growing adventure! Reminder that the deadline is May 31st for Fall Delivery. We look forward to working with you for your projects!

Where is the best place to put the greenhouse?

Considerations for determining optimum location for growing,
air flow, snow shedding and ground moisture

The first bit of advice we share when asked that question is “Do not put a greenhouse in a place that is not good for anything else”.

You need to pick the best spot to accomplish the goals for your greenhouse. Any of the reasons why this spot would be less than desirable, will come back to haunt you.

This is particularly true when it comes to ground water. If a particular piece of land is always moist or has a very high water table, moisture will be an ongoing problem. A greenhouse will trap and exaggerate excess moisture and become a very unhealthy spot for plants.

If the soil is sub-standard or undesirable where you put the greenhouse, you will be putting extra effort into bringing the soil up to standard.

Proper consideration needs to given to shading on the property. Plants grow in direct proportion to the amount of daily light they receive. Really analyze where and when shade happens. Vegetables and flowers need sun.

A greenhouse needs to be level from side to side so shed snow uniformly. With uneven snow load on a building, it will surprise you how little snow can be a problem. 

Excavation to level a site is usually expensive and messes with the make up of the soil. There are ways to build up the low side if that becomes necessary for the location of your choice.  Some end to end slope is not a problem structurally.

It is generally acknowledged that a north/south orientation will pick up the sunlight better but this is not a serious consideration unless you are into production crops.

If your prevailing winds are constantly hitting the side of the structure, there will be a sideways push which is good to avoid. This orientation will also encourage uneven snow loading. Ventilation is typically easier if the prevailing wind hits the end of the building.

Since the chances of having the “perfect” location, is not likely, it is important to evaluate all of the angles.  Some of the undesirable points can be worked around better than others.

By doing a thorough assessment and then prioritizing, you will be able to come up with the closest to perfect that is practical. You will also have an idea beforehand on what needs to be done sooner than later.

Here is to happy planning and planting.

We hope you find value in this series of posts, helping you prepare for your new growing adventure! Reminder that the deadline is May 31st for Fall Delivery. We look forward to working with you for your projects!