We have been trying to grow a number of plants, indoors, and having a lot of difficulty with some species. In our efforts, we have learned it is difficult growing plants indoors.
Being near the end of our rope, we decided to contact an expert. Mike McGrath is the host of a show on PBS (WLVT 39) called “You Bet Your Garden” where he provides expert advice to home gardeners, like us. We’ve learned a lot from the show, just watching the episodes.
We sent Mike an email about our issues growing white sage indoors, in December 2018. Within a couple days we received an invite to be an on air call to discuss growing white sage indoors. Although the call has not been aired yet, as of this posting, a lot was learned in that short call. What was learned is reflected throughout this post.
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I recall in an episode where Mike was talking to a woman about her tomato plants. Mind you, this was about tomatoes outdoors, not inside. He explained that a few plants spread further apart in the same space as she had several plants would yield better results, simply because of better air movement and sunlight absorption. When the plants are too close to each other, they shade each other’s leaves and air cannot pass through as well.
When visiting garden center greenhouses, we noticed that they have fans, not only for ventilation but for moving air around the enclosure. Taking from this cue, we needed to make sure that air moves within the enclosure. We put in a small, low powered fan near the middle of the enclosure, pointing towards the furthest side, on the lowest setting. This created a gentle breeze that not kept the air moving, but evened out the variations of temperature we had in different zones of the enclosure.
When growing plants indoors, there needs to be a variation in temperature to simulate night and day. Some plants need winter simulated also.
For our white sage, daytime temperatures were reaching about 80F during the day and dropping to about 68 at night. Mike told me that this was not a large enough temperature variation. He recommended have a 20-ish degree Fahrenheit variation between daytime and night. That gives us a challenge, but we are working on it.
With our white sage plants, they would struggle in the middle of summer outside in full sun. You wouldn’t expect this for a desert plant. Then we realized it was because of the humid summer conditions in Pennsylvania. The desert is usually a dry heat, high humidity doesn’t exist – except when it’s raining, of course.
Within our indoor greenhouse, conditions kept getting humid. We added a container of calcium chloride crystals to draw the excess moisture out of the air. This concept would not work for plants that love humidity, but it is helping the plants we are growing indoors.
Plants Need Light
Outside plants need light, even shade loving plants. When trying to grow these plants inside your home, adequate light is needed. Mike made it clear in my conversation with him, and on multiple episodes, that the more lumens of light and having the plant close to the artificial source of light, will improve results. A simple four foot shop light with fluorescent or LED light tubes should be within a mere inch of full sun plants. The light fall-off is rapid beyond one inch (or so).
Following the instruction of more, closer light, we moved the fluorescent fixture to inside the greenhouse enclosure. This would also help with the temperature variation needed for our White Sage, as the heat generated by the fixture would increase the inner temperature of the enclosure.