Katherine Clarkson

A November column introduced the importance of artificial and natural light when growing an indoor garden. Besides lighting you will also need to monitor temperature, humidity, water and nutrition. These elements play a significant role for growing lush vigorous plants indoors.

I consider light to be the most prominent component for plant growth with temperature being the second most vital element.

Plants thrive within various temperature ranges. When outside of these ranges, plants shut down and struggle in an environment that is too hot or too cold. Generally, the optimum temperature for photosynthesis is 77 degrees Fahrenheit (25 degrees Celsius).

An ideal day temperature is between 70 to 80 degrees and a night temperature of 60 to 70 degrees. However, not all interior plants like the same temperature. For example, cyclamen is a cool loving plant tolerant of low 60 degrees, and ferns do well at 72 degrees.

Another aspect of growing indoor plants is the element of humidity. Being a native of Buffalo, New York, I learned to love humidity, so upon entering my greenhouse you would instantly perceive the muggy air.

Plants need humid air to flourish because they cannot always restore the moisture they lose through root absorption; therefore precipitation is consumed through their leaves. The thinner the leaf, the higher its demand is for moisture. You can increase your humidity by misting your plants, though foliage and plants with “hairy” leaves should not be sprayed. Keep a shallow container with rocks and water under your plants. Lastly, place the plants closer together which will establish a microenvironment with greater moisture.

While temperature and humidity are vital, understanding how to water is incredibly important. Take into consideration the succeeding factors. Not all plants have the same water demand — larger plants require more water compared to smaller ones and the size of the container also plays a role. If the container is small, you may have to water it regularly.

The amount of light can alter the amount of times you water. Under high light plants will transpire more, which will contribute to more frequent watering. All these factors can influence how often you need to water.

Just like people, plants also require daily nourishment. Here are some general rules of thumb to follow: use a fertilizer specially for indoor plants and use about one-fourth the amount of fertilizer that is recommended for monthly application. Newly purchased plants seldom require an urgent application of fertilizer. During winter, fertilize less than in the summertime.

Also, if the overall color of the leaves becomes a lighter green, fertilize every two weeks; if the new growth is dark green but the leaves are small and the internodes seem longer than the older ones, reduce the amount of fertilizer. If you over fertilize your plants, the water in the soil becomes too salty and “burns” the plant’s roots.  You can notice this issue because excess soluble salts accumulate as an opaque crust on the surface of the growing medium.

We have now addressed all the vital components needed for a happy, healthy and successful indoor garden. Some of you may have noticed that I titled this column: How to grow your indoor garden. I prepared a spot for my indoor garden and I would love your suggestions of what vegetables to grow. I am seeking two vegetable suggestions from Cody and two from Powell. I will adopt your recommendations and maintain notes on what each plant requires to be prosperous. I will post the results in a future column.

Thank you for the remarks and inquiries I previously received! Please email me at katherineclarkson2@gmail.com with your ideas or questions.

(Katherine Clarkson is the president of the Park County Master Gardeners. She lives in Wapiti.)