Lighting for Streptocarpus

By Dave G. (Strepbystrep) on June 27, 2014

Being closely related to the African Violet it is not a coincidence that streps will grow and thrive in the same lighting conditions as their cousin whether it be natural or artificial lighting.

Lighting for Streptocarpus

Being closely related to the African Violet it is not a coincidence that streps will grow and thrive in the same lighting conditions as their cousin whether it be natural or artificial lighting.

So let's start with natural light. What exposure is best? Ideally, a East, West or North exposure would be Fine. Early morning sun, dappled or indirect light is ideal. NEVER put a Strep in direct sunlight for any extended period of time. The result will be sunburn on the leaves.

An East exposure will give early morning sun, which in general is fine. I would caution anyone who gets sun later than 9am to place a sheer curtain between the plant and the window. Though morning sun at this time of the morning is not the most intense, the window will start to act as a magnifying glass and will heat the leaf surface of the plant as the day progresses.

The West exposure will provide afternoon sun. Though the sun's intensity is generally winding down later in the day, between the hours of 2pm-5pm it could cause sunburn. It would be wise to have a sheer curtain between the window and plants especially in the mid-spring to early fall time period.

A Northern exposure is the least desirable of the three. With this exposure there will be only indirect light. However, if there are no overhangs or trees shading the window, this could be an ideal exposure to grow streps. Generally, a northern exposure will be cooler, which unlike AV's, streps tolerate better.

You maybe thinking is there enough light? Here is a good way of judging if you have enough light for your plants. Take a plant and place it where you intend to grow. Now place your hand 12" away from your plant. If you see a distinct shadow, you have sufficient light. If you can not see a distinct shadow, here's how to increase the light in your growing area. Take aluminum foil, shiny side up and place as a liner on your windowsill or shelf. Place your plant(s) on the foil. The foil will reflect light back to the plant and will increase the amount of light intensity the plant(s) receive.

This truly works! I worked as a church secretary for several years. The office only had North facing windows. I bought a baker's rack and lined the shelves with aluminum foil as I described above. The rack was 3' from window. The streps not only grew but bloomed abundantly. Many members of the church were amazed by how good the plants grew!

This will work for any other exposure where you may not be receiving adequate sun due to trees or maybe a roof overhang. NEVER, NEVER use aluminum foil where direct sun can reflect off the foil. This is a sure fire way to burn and kill your plant!

Now let's talk about artificial lighting. Why artificial instead of natural? There are different reasons why someone may choose this method of growing.

One, they may not feel they have the proper lighting. Secondly, they may not have the space needed to grow a collection on a windowsill. Thirdly, some growers like the consistency of artificial lighting vs. natural light. There are no cloudy days under lights.

What lighting set-up do I use? T-12, T-8, T-5, LED or other lighting? There are so many choices to choose from today.

I will give advice based on what I currently use and experience. Personally, I chose T-8's when I started growing under lights. My decision was based on T-12's being eventually phased out. I use T-8 outdoor shop lights, 4 foot fixtures with 2 bulbs which are inexpensive and available at WalMart, Lowe's or Home Depot.

I use the cheapest bulbs I can find, (usually cool white) 32 watts with a minimum of 2800 lumens. You may ask, "what about those special grow lights they sell?" While they do
provide more of the blue to red spectrum needed by plants, the cost of the bulbs vs. results does not in my opinion warrant the extra expense which can be 2-3x the price of the cheaper bulbs.

Lights should be hung 12"-18" from the top of the pot, with 18" being the absolute maximum. Lights too close to the plants will produce yellowing leaves where as lights too far away will produce plants with leaves reaching toward the lights. (Note: there are a few hybrids in circulation whose foliage grows more upright; Dibley's Ice Series) I have my lights set at 14", the plants grow and bloom well even in the hot days of summer.

General rule for growing under lights is 12-16 hours per day. My personal preference is to use this schedule, during the months of March-October, I leave lights on for 12hrs. per day. November-February 10hrs. per day. This works well for my conditions and plants. You may have to experiment to get optimum results for your plants.

As bulbs age they will gradually lose their intensity. Bulbs generally will last 5 years depending on manufacturer. My personal recommendation is to mark your bulbs with the date you set-up your lights. When your lights reach the 2 year mark, replace 1/2 of your bulbs. Then 6 months later the other 1/2. This will ensure your lighting will be consistent and plants will receive adequate lighting at all times.

There is much debate among growers as to which lights are better. T-5's are very popular among some growers as one T-5 bulb per shelf is equivalent to the amount of light a plant receives from 4 T-8 bulbs while using only 2/3rd the amount of electricity. All of the lights listed in the beginning have their good points and bad, it's really a matter of preference and what you're willing and/or can afford to spend.

Now you have the basic knowledge, it's up to you which way you will grow your plants. Natural light or artificial, both will produce many wonderful healthy plants with many blooms to brighten your day!


Related articles:
artificial lighting, Light, Streps, Streptocarpus, windowsill

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Comments and discussion:
Subject Thread Starter Last Reply Replies
Thank you gardengus Jun 28, 2014 7:14 AM 0


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