Window Sill Gardens

Many people wish they could garden, but think they can’t because of where they live. Nothing could be further from the truth.

Container plants can grow on window sills and in sunny rooms without the addition of artificial light, assuming the area receives 6 to 8 hours of sunlight each day. Grow lights can also be used for even better growth. Growing edible plants serves many purposes: cleaner air, tastier food, less fossil fuels being burned, and, hey, container gardening is fun!

Indoor basil, cilantro, parsley, thyme, chives, and a tomato plant! [March 4, 2025]

How to create an indoor garden

Start your window sill garden with these questions:

• How many windows are available?
• How many hours of sun does each window get?
• How wide/deep are the sills?
• Can hanging plants be installed near windows?
• What seeds and plants are available?

Choosing plants for your window sill gardens

The next step is deciding what to plant. Being grown indoors, many of these plants will need to be hand-pollinated, but it's not difficult.

• What will you actually eat or use?
• Herbs are excellent choices for window sill gardens. They don’t need much care and most of them are damn near indestructible, once established (except basil). Oregano makes a lovely hanging plant, chives will continue to produce for years, and thyme and rosemary are very fragrant. 
• Fresh tomatoes, melons, squash, and cucumbers taste divine and are surprisingly easy to grow. They can be trained up a trellis, net, or a lovely dried branch.
• Climbing nasturtiums are edible and lovely.
• Potatoes and strawberries grow for many years in a tower, bucket or trash can. Strawberries can also be grown in hanging baskets.
• Citrus and other fruit trees can be grown indoors.
• Blueberry, raspberry and blackberry bushes can grow in containers.
• Climbing (pole) beans can grow up a net hung over a window and dramatic red noodle beans look striking in a hanging basket.
• Radishes need very little space and they grow fast.

Window sill garden containers

When selecting containers for edible plants, it is critical that they be safe for food. Many plastics and ceramic glazes can be toxic. That being said, you can often find food-grade containers for free at local restaurants. They often buy food in bulk in large plastic tubs that are safe for food. Just ask the manager.

If you opt for a tub, you will have to create drainage holes. Over-watering and poor drainage kill more container plants than everything else put together. Contrary to popular belief, it is not a good idea to add rocks at the bottom of planting containers. Rocks take up valuable soil space and provide fungal spores with a great place to reproduce. Just be sure there are a couple of holes at the base of plant containers to allow water a way to escape. Place tuna cans, coffee canister lids or plastic packaging under plant containers to catch excess water.

In my experience, self-watering containers are the best choice for indoor gardens. They eliminate the possibility of overwatering while providing easy access to water and nutrients for your plants' root system. You simply add water and fertilizer to the base and the plants do the rest. Hydroponic planters are another excellent option.

Indoor dill and zucchini

Hydroponic herb garden

Soil for window sill gardens

There are several sources for soil for container plants:

• You may be tempted to dig up soil from outside, but that’s risky. Dog, cat, and rat urine may be present, along with weed seeds, fungal spores, and other undesirable microorganisms. If ground-scored soil must be used, look for an area that is already home to healthy-looking plants.
• When buying soil, opt for potting soil over planting soil. Planting soil is formulated for use outside, while potting soil is for container planting. Potting soil holds moisture and nutrients better than planting soil.
• Another source for soil may be a local municipal solid waste company or the city itself. In an effort to reduce landfill needs, most municipalities now offer curbside collection of yard waste, which is then composted and returned to the community. The quality may be questionable because of those short-sighted individuals who toss plastic, diseased plants, and doggie-do bags in with the yard clippings, but most cities and companies sterilize the soil, making it a viable source for free or inexpensive soil.
• Container plants will use up nutrients in the soil, over time. Adding compost, fish emulsion, or other fertilizer will keep container plants well fed.

Seeds & plants for window sill gardens

• Food can often be grown from food that’s already in the house. Celery, scallion, leek, and onion ends and potato eyes can all be planted successfully. [This method is not recommended for outdoor gardens as these plants are not certified as pest- or disease-free. If a container plant gets sick or infested, you can toss it out and start again. It’s not that simple when they are outside, near other plants.]
• Some local libraries offer seed libraries, where seeds for a window sill garden can be ‘checked out’. If not, you can start your own seed library!
• Local Master Gardeners can often help you find seeds for a window sill garden.
• Some plants can be started from cuttings and layering. Layering refers to the way plants, such as rosemary and the bramble berries, start roots at the end of a growing tip that has come into contact with the soil.

It’s time to plant!

Plants are more likely to grow to their full potential if they are planted according to the directions on the seed packet. If that information isn’t available, look around in The Daily Garden.

Hand-pollination

To get fruit from most plants, the flowers need to be hand-pollinated. This is very easy. Just grab a small paint brush, Q-tip, or something similar, and touch it to each of the flowers every couple of days until the flowers start to turn brown, using the same tool each time. This bee-ly duty will transfer pollen from one flower to another, completing the pollination cycle. You should probably use a different tool for each species, though I’m not sure it actually matters. Self-pollinating varieties don’t need this.

That’s all there is to it! Start your window sill garden today for year-round flavor and fun!

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UPDATE [April 4, 2025]: Check out how quickly my window herb garden is growing! My zucchini plant has some male flowers and the tomato plant has flower cluster, too! I will use a small paintbrush to and the male flowers to hand-pollinate once the female flowers appear.

Chives, garlic, scallions, cilantro, basil, and thyme, plus a tomato plant all growing on a windowsill!

Zucchini plant with male flowers, dill, and rosemary growing beautifully in containers.