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What is VPD and why should I know about it?

Posted by Brendan 20/03/2019 0 Comment(s)

What is VPD and why should I know about it? Spectrum King's Brendan Strath explains:

VPD stands for Vapor Pressure Deficit and essentially is the amount of moisture that air can hold in balance at a given temperature. When growing plants  this is very important as we want to create the proper environment for your chosen plants to thrive in. When growing tropical plants for example they are accustomed to hotter and more humid environments. When following a VPD chart (see attachment and research it to give credit to whoever made it, it’s not mine ) you’ll notice the sweet spot in gold. You can see that the higher the ambient temperature the more moisture it can hold in balance to stay in the optimal zone. Tropical plants thrive in higher temperatures with high humidity. You would not have it very cold and wet for tropical plants as that would create a whole myriad of problems for them nor would you want it very hot and very dry for them either. If you were to grow evergreens or mountain flowers you would know that they are accustomed to larger temperature changes from day to night and dryer air than tropical plants for example.

By following the VPD chart and researching the origins of your plant selections you can establish the proper conditions for day and night or for indoor grows lights on and lights off to get the best results from them. It takes the guess work out of your gardening and helps you better understand the conditions needed for your chosen plants to thrive in. When growing hybrid plants sometimes referred to a cross-bred, you will find yourself oftentimes leaning towards the dominant traits of the plants which will indicate which conditions they prefer. It can be a fun exercise to educate yourself with and help you improve your gardening skills. After all plants are the most honest creations on earth and will show you very clearly if you are giving them what they want and need or not. By knowing the origins of your crops and the conditions they are accustomed to you can pair equatorial plants in one space and northern mountain plants in another and by following the VPD chart you can establish the preferred temperature and humidity ranges each zone prefers. With just a little research you can know the intensity of light each species prefers, the microclimate of their place of origin, and what nutrients they require. The right light source and feed source won’t do the job alone, although equally as important, as getting the environmental conditions right for your plants. Knowing the VPD chart and how to read it gives you a tool to better control your environment and to better care for your plants.


Brendan Strath: Senior Solutions Director and Grow Ninja at Spectrum King LED, that is what Brendan's e-mail signature says. Brendan knows everything about plants and everything about grow lights. He is a walking encyclopedia and an attraction at every trade show, because everybody recognises him and wants to talk to him. Brendan likes to take time for everybody who wants to talk to him about growing plants, because first and before all, he is a grower (these are his own words). Brendan will we addressing hot topics about growing plants with LED grow lights on a regular basis, exclusively for LED Paradise.

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