Growing Indoor Edibles

Micro-greens grown in an unheated greenhouse in winter

First, a confession: I kill houseplants. More than one visitor has suggested I put a suffering plant out of its misery, saying, “You’re a landscape architect – it’s bad advertising.” When my indoor plants have a purpose, like being edible, I do better. Not only that, but recent advances in indoor growing methods and technology are making this type of gardening, even year-round, more affordable than ever before, though not necessarily less complicated.

How to Think About Indoor Edibles

There are three considerations involved in indoor growing: the growing system, what plants you grow, and what those plants need to thrive. For most people, some combination of cost, available space and time will guide choices in growing systems, which range from fairly simple to fantastically complex. 

If you search online you will find many cool DIY ideas for creating shallow, attractive planters for sunny windowsills. This simple, low-tech option is great if you have a sunny windowsill, no cats, and you want to grow wheat grass, lettuce, and other greens that do not need more than a few inches of soil or other growing media. If you’re home often enough to water you won’t need to irrigate. Start here if you are not looking for a serious new hobby and want to spend under $100 for your winter micro-greens.

Online resources abound, including, with its long list of topics and videos. See especially, articles on SIP, or sub-irrigation planting, where you can recycle yoghurt containers and straws to create watering wells below your soil, evening out the watering cycle and making out-of-town week-ends possible without needing irrigation or an apartment sitter.

Growing Systems – Cash or Credit

If you don’t have a sunny windowsill, you will need to purchase grow lights and possibly reflectors and circulating fans. If your temperature is uneven, you may want to purchase electrically heated mats to place below your plant trays. You can purchase Gro-Block plant starter cubes made of spun fiberglass or other soilless growing media made of spun cotton or recycled soda bottles, or designer soil mixes with names like Ancient Forest or Happy Frog. You can purchase liquid fertilizers with names like Buddha Grow or Buddha Bloom, or bags of bat guano imported from Mexico. 

According to Chris Hauser at Capital City Hydroponics in Petworth, which sells all these products, this is the “craft micro-brew equivalent of soil media.”  When I look at the trade names of these products, I feel like Diane Keaton’s character in Annie Hall who famously said, “I love being reduced to a cultural stereotype.” As I write this, a bottle of Buddha Grow by Roots Organics sits on my desk, and a 60 pound bag of Happy Frog soil mix rests in the back of my Prius. I wasn’t kidding about Annie Hall.

Do you have to spend a fortune? No. For a system with lights you can get one generic set of shelves from a place like the Container Store, plus one set of fluorescent lights (under $90) and start small. If you want to take a dip into hydroponics you will spend more. These systems have reservoirs, pumps, growing trays, water purifiers and lights. Think of it as a hobby akin to salt water aquariums, which is very satisfying, but demanding and potentially pricey.

If you are not growing hydroponically, you will either use a soil media or a soilless media. Chefs like growing micro-greens in soilless media because they can pull up entire plants without having to painstakingly wash soil out of them. This is where the liquid fertilizer comes in. If you have kitchen counter space, consider installing fluorescent grow lights below your cabinets, and place soilless growing trays below them for a conveniently located and attractive source of greens, or leafy herbs like basil parsley and tarragon. 

One trip to Capital Hydroponics (  will make all this quite clear, as they are a full range organic gardening supply store, and the only retail and wholesale hydroponic supplier in the region. Founded by Mike Bayard three years ago in the up and coming Petworth neighborhood, they are already scouting around for a second location. The store has a speakeasy feel. When you go to their street address at 821 Upshur Street, NW, you find Domku, ( a Scandinavian and Eastern European restaurant . Capital City Hydroponics is down the alley behind the street, with a metal door and buzzer. Once you are buzzed in, go downstairs for the basement level shop. You will find everything there except plants. 


The biggest reason indoor growing has become easier, less space intensive, more affordable and energy efficient than before is the dramatic advance in lighting technology over the past five years. This will continue, ultimately making large scale indoor growing economically viable. For example, you can purchase one LED fixture, the SolarFlaire 220, by California Lightworks, for $500. It lasts forever, lights a 4’x4’ area, emits almost no heat, costs pennies to run, and offers complete spectrum illumination. Four years ago the same fixture cost $2,000. Prices are still falling. 

Florescent lighting has also seen vast improvements both in energy efficiency and light quality.  According to Hauser at Capital City Hydroponics, two American companies are “the Ford and Chevy of indoor lighting.” They are Hydro Farm, out of Petaluma, California, and Sunlight Supply from Vancouver, Washington. 

These light options replace the old ubiquitous high pressure sodium lights that are costly to run, heat emitting, and cumbersome with their fixtures and ballasts.

What Indoor Plants Want

Planting a radish seed outdoors is simple. Nature determines light intensity and duration, humidity, moisture, and temperature. Planting indoors requires you to consider and control all these factors as well as nutrients which must be managed indoors or out. Some plants like it hot, like peppers and tomatoes. Others like it cooler, like lettuce, spinach, chard, kale, parsley or arugula.  Greens are shallow rooted. Tomatoes, peppers, and carrots need more root depth. Radishes are in between. 

The company, Mighty ‘Mato (  sells grafted fruit and vegetable plants, including cherry tomatoes that are great for growing indoors.  The root stock of one plant variety are grafted with the body of another, offering greater disease resistance and bigger yields. Hauser claims they offer a one foot tall cherry tomato with incredible yields, suitable for indoor growing. That might make it worth paying $12 for a single tomato plant . 

Finally, I have grown salad greens in a small free-standing greenhouse, available from Costco for under $800. If you have the yard space, this is another option. To harvest the greens, I cut or tear off selected outer leaves of each plant and never pull any plants out entirely. My greenhouse stayed above freezing all winter, even though it was not mechanically heated. By opening and closing the door and window, I could control the temperature well into May, when it became too hot and I moved the operation outdoors again. 

As autumn begins, so does a new gardening season.

Go around the alley and buzz to enter Capital City Hydroponics
An inexpensive, energy-efficient florescent light and simple shelves for indoor growing

Cheryl Corson is a licensed landscape architect who works on Capitol Hill and beyond. She is an avid gardener and fermenter, and just happily re-launched her web site,

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