An experiment in growing vegetables indoors: Part I

Photo by Naked Food

As I  gazed out upon my beautiful snow-covered garden, I couldn’t help but daydream about walking outside barefoot and picking ripe vegetables to use for dinner that night. If only I had a greenhouse! But then, I started thinking about all the articles I have read about growing vegetables inside during the winter. My curiosity gears started moving. Could I really grow vegetables inside throughout the winter?

I figured it was worth a shot. At worst, I’ll learn something—and I’ll get to spend the cold winter months with my hands in the soil. At best, I could be eating fresh, homegrown meals all year round! I decided to start a small trial, to see if I could grow a few vegetables on an indoor windowsill.


Naturally, plants have different requirements for growth. Before picking out which vegetables to grow, I needed to evaluate my living space (aka “the ecosystem”) based on 7 properties: light, temperature, soil, humidity, air circulation, water, and space.


Flower pots and sill trays on the sunroom floor with Green Mountain Compost soils.
The sunroom

I have a sunroom that receives as much light as the day provides during a New England winter, which isn’t really all that much. Specifically, between December and March in Vermont, the daily average is 4 to 5 hours hours of sunshine. Due to this constraint, we may see some unfavorable results in some of the chosen cultivars. I will record daily light observations through the trial.


The sunroom temperature can range between 68°F and 76°F, which is ideal for most vegetable growing. I will record daily sunroom temperatures throughout the trial.


Thankfully, I trust the soils I will be using for this trial as they are tried-and-true blends of great ingredients. Of course, I’m talking about Green Mountain Compost Premium Organic Potting Soil and Premium Organic Raised Bed Mix.

The potting soil is made with regionally sourced sphagnum peat moss, premium compost, aged pine bark, and a mix of organic fertilizers. The raised bed mix has premium compost, silt, sand, sphagnum peat moss, and organic fertilizers.

I decided to grow the same vegetables in each medium to add an extra layer of discovery (and excitement!) to the trial.


Since a lot of houseplants are growing in the same room, the sunroom should provide adequate humidity. I will need to keep an eye on the moisture content when the woodstove is burning, as it can dry out the air.

Air circulation

The sunroom has a ceiling fan, which will be on everyday during the trial. Not only will this help create a more realistic outdoor-ecosystem feel for the plants, but it will help evenly distribute moisture in the air and prevent mold growth.


In terms of the area where the plants will grow, I gathered containers that will make up the garden. Different container depths are needed for the different cultivars. For instance, root vegetables need deeper containers while microgreens—with their micro roots—need shallower ones.

Additionally, some vegetables need room to grow outside of the soil, so this will be a factor when choosing what to grow. To best suit a variety of spatial needs, I was able to rustle up 2 deep planter boxes, 2 shallower planter boxes, and 2 medium sized pots. I will use two of each so that I can test both soil mediums.


Care should be taken to ensure that the water used won’t harm the plants. Water softeners remove plant-friendly minerals like calcium and magnesium and exchange them for the sodium part of the salt that is found in the softener. Too much salt will eventually kill plants.

I will be using well water out of my tap; there are no additives in this water. I will record daily watering observations and follow instructions for the different vegetable needs.


Indoor vegetable gardening does have some constraints. I have to accept that without grow lights and other variables, things like cucumbers, peppers, tomatoes, corn, and squash are just out of the question for the physical environment I can provide. But that doesn’t mean I can’t try a few others!


These will be planted in the deep planter boxes, as they need depth for their roots to grow. They need about 5 hours of sunlight or they will take a lot longer to grow to their desired length. I’ve chosen the Scarlet Nantes variety which are a deep orange that produce 6”-7” roots in about 65 days. I’ve planted them in 3 rows with a row of radishes in between. Fingers crossed!


The Crimson Giant radish is a cool season crop which matures in about a month. I’ve planted them in rows between the carrot rows because, in theory, they will be ready before the carrots. Once I pick the radishes, it will give the carrots more room to grow. Radishes need between 5-6 hours of sunlight to effectively grow but are also shade tolerant. Hopefully the sun shines bright and we’ll see some crunchy, spicy, bright red fruit in about a month!


Of course I decided to play around with garlic because, let’s face it, I love it! Garlic needs about 6 hours of sunlight and it should sprout green shoots. If I want to try to grow an actual bulb, I’ll need to keep them growing for about 8-10 months. I’ve planted 3 cloves on each end of the deep planter boxes equaling 6 cloves per soil medium. Exciting!


I think beans will be a stretch to grow but I wanted to try at least one vegetable that requires more sunlight and warmer temperatures, just for fun.Seed packets in front of windowsill planter filled with soil. I’ve planted 6 beans in each pot but will thin to two plants once they germinate. I want to give them ample space to grow outside of the pot if they decide to cooperate with the less than favorable conditions I’m forcing upon them! I’ve chosen the Royal Burgundy bush bean variety, as they are favorable container plants and high yielding.


I’ve chosen to plant microgreens because, after reading Year-Round Indoor Salad Gardening by Vermont native Peter Burke, I’m confident that they will do quite well indoors.

The varieties I’ve chosen should reach harvesting point between 7 and 20 days. Peas (for shoots), sunflowers, red winter kale, and a savory mix can be grown to a young, tender state, or when their first leaves are apparent. Peter wrote a nice synopsis of his salad gardening techniques in this Mother Earth News article.


Stay tuned!

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