The science behind the relationship between plants and light is complicated, but my guest on this week’s encore episode explains it in an accessible, easy-to-understand way. Her name is Leslie Halleck, and she is an expert on lighting for indoor growing. In our conversation, Leslie explains what gardeners need to know about light to raise houseplants as well as herbs and vegetables indoors.
Leslie is the author of “Gardening Under Lights: The Complete Guide for Indoor Growers.” Both veteran gardeners and those with no prior growing experience can benefit from this book’s advice on how to successfully grow ornamentals and edibles indoors. She has since released the book “Plant Parenting,” and in April 2021 her newest book, “Tiny Plants,” will be published.
Leslie is a certified professional horticulturist with a Bachelor of Science in biology from the University of North Texas, where she focused on botany and plant ecology, and with a Master of Science in horticulture from Michigan State University, where her graduate research focused on greenhouse plant production using environmental controls such as lighting, photoperiod, vernalization and temperature. She has nearly 30 years of experience across several fields in the horticultural industry, and today she runs Halleck Horticultural, a consulting and marketing firm for the green industry.
The amount of light that plants receive drives photosynthesis, Leslie explains, but plants don’t measure light in terms of brightness. Rather, they quantify light in terms of volume. Plants are nature’s solar panels, turning light into energy, which they store and then convert to fuel for different processes for growth.
The white light of common lightbulbs is full-spectrum, while many grow lights on the market appear pink or purple because they are dual-band lights providing the most efficient light for plants to absorb: red and blue. Leslie says that blue light generally drives more vegetative growth, while red light stimulates roots, shoots, flowering and fruiting — and that’s why some high-tech grow lamps offer controls over the different bands of light.
For details on the importance of light, from how it affects plants on the cellular level to striking the correct balance between periods of light and periods of darkness, check out the show notes from the original airing of my conversation with Leslie.
If you haven’t already listened to my conversation with Leslie Halleck on the science behind lighting plants indoors, you can do so now by scrolling to the top of the page and clicking the Play icon in the green bar under the page title.
How do you provide supplemental light to your indoor plants? Let us know in the comments below.
Links & Resources
Some product links in this guide are affiliate links. See full disclosure below.
joegardener Online Gardening Academy™: Three popular courses on gardening fundamentals; managing pests, diseases & weeds; and seed starting.
joegardener Online Gardening Academy Master Seed Starting: Everything you need to know to start your own plants from seed — indoors and out.
Disclosure: Some product links in this guide are affiliate links, which means we would get a commission if you purchase. However, none of the prices of these resources have been increased to compensate us. None of the items included in this list have any bearing on any compensation being an influencing factor on their inclusion here. The selection of all items featured in this post and podcast were based solely on merit and in no way influenced by any affiliate or financial incentive, or contractual relationship. At the time of this writing, Joe Lamp’l has professional relationships with the following companies who may have products included in this post and podcast: Rain Bird, Corona Tools, Milorganite, Soil3, Exmark, Greenhouse Megastore, High Mowing Organic Seeds, and Wild Alaskan Seafood Box. These companies are either Brand Partners of joegardener.com and/or advertise on our website. However, we receive no additional compensation from the sales or promotion of their product through this guide. The inclusion of any products mentioned within this post is entirely independent and exclusive of any relationship.