by Amber

Windowsill Garden Results

I was expecting leggy plants, perhaps even total crop failure depending only on the dismal amount of sunshine we get in the middle of the winter. I have tried cilantro before and it always just gives up and dies before there is anything to snip. Lettuce is a bit more forgiving, but grown in the winter windowsill garden without lights? It looks like it’s not been watered enough in this image, but that’s not what is wrong.

Dam Cat Meets Windowsill GardenDo you have a cat? It might decide to investigate that earthy smell detected way up there in the window. The lettuces looked great – all things considered – before I went to bed. In the morning they were upside down on the kitchen counter and there was potting mix everywhere! The plants were pretty busted up, but why not see if they’ll repair? At this point, things can’t get any worse.

So the dumped soil that I could collect was put back on top of the roots. I watered them, and luckily they perked up quite a bit by nighttime. There was some leaf loss from stem mutilation received in the fall. Easily located the next day hanging shriveled and removed. This kind of thing is bound to happen unless you’ve got a sealed growing space. Bumped by accident. Toppled by curious kids or pets. Even in a summer garden, things can happen to your plants outdoors.

Prior to the accident, the lettuce was given 3 hours of CFL light assistance on cloudy days only. See how the lettuce closest to the light is larger, leafier and perkier? The light is not where both plants can use the energy… I know, bad light installation. But there’s something there to hang it on without making new holes in the woodwork 😉

While there is always more sunshine in February than in January, and even more come March, the slow and stretched growth is a sure sign that the plants do not have the energy to do their thing properly. As you can see, this small light assistance boosted plant performance quite a bit. However…

After 10 weeks the leaves on one plant give you enough to add some greens and a light crunch to your tuna sandwich. This is not what they call ‘garden efficiency’. If this was the sole source of your salad greens, just one small salad every 3 months is not what you’d call self-sufficient. You definitely must have grow lights to assist the available sunlight – even in a window with Southern exposure.

There is also the temperature issues in a windowsill. Unless you have newer and high quality windows, there will be cold air seeping in around your plants. Anyone living in an old building in a downtown area won’t have such windows. Those cool looking old windows aren’t your food’s friend. And even when you have well-sealed window glass and framing, the temperature this close to the glass will be colder than a foot or two away. It will be hot in the late afternoon and chilly after sundown. No plant will be at it’s best in this kind of environment.

Here’s is one other thing to point out. Standard vegetable cans are free planters once you clean them up and pop some drainage holes in the bottom. Expect to have issues with the roots getting dried out too fast as your plants get bigger. Between the dry air from heating indoors in winter, and the heat of the sun being magnified by the glass in your window, you will have to check the moisture available in your growing containers daily to keep them from getting weak from the drought conditions in your toasty abode. A larger can, like the ones you buy tomatoes in will give you more moisture retention, but only until the roots have taken over the compact space.

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  • Jeff says:

    Hi Amber. If you’re interested in a lighting upgrade for your windowsill, my company (TotalGrow Lights) has an 11W full spectrum LED-based grow light bulb that will grow better than a CFL using far less electricity, without the mercury over your lettuce. I’d be happy to share more about it including other people’s experiences if you’re interested. The easiest source for this specific light is probably gogrowlight.com if you’re interested. Good luck with the salads!

    • Amber says:

      I can appreciate your suggestion, Jeff, but the entire reason for this windowsill garden experiment was to see just how effective growing food with nothing but the sun coming through the window was. And just as suspected, it won’t be alleviating hunger any time soon.

      I had a look at your grow lights, and don’t think they would work in a residential window without modification – for several reasons:.

      1. The cord is too short. How is that supposed to plug into the wall without a bunch of extension cord hanging around? My HO T5’s have 15 foot of cord just to reach the electrical outlet.
      2. TotalGrow is nothing but a cord with sockets. A person would have to fabricate something to hang the string from which could then be hung in the window without a bunch of hooks screwed making 8 screw holes in the window frame or molding.
      3. Once mounted with what comes in the box, there is no way to adjust the light height, and the top of the window frame is way to far above the plants for effective grow lighting. Especially with low energy LED

      The light setup in this project was chosen because it was the kind of thing that most new indoor gardeners try, because it’s super inexpensive. And that cobbled together light used here shows that with a spot of light, you get a spot of growth. The part that the plant cares about doesn’t spread – it falls straight down from the center.


The garden played a starring role from spring through fall in the house Amber was raised in. She has decades of experience growing plants from seeds and cuttings in the plot and pots.