Gardening on Windowsills
Fresh food in the smallest of places—that’s what planting up some pots and placing them on a sunny windowsill can get you. You don’t need a backyard, patio, or even a balcony to grow your own food. With the right container and a little planning, a sunny windowsill can become a productive mini-garden. From fragrant herbs and crunchy microgreens to sweet pea shoots and tender greens, edible windowsill gardening can give you fresh flavor for your kitchen year-round.
We’ll tell you exactly what you’ll need to get a garden growing in your sunny window.
Light
Light is the single most important factor in successfully raising food inside your home. Most edible plants need at least six hours of bright light on a daily basis. If you can provide eight hours, even better. South-facing windows usually provide the strongest light, while east-facing windows work well for herbs and leafy greens that prefer less-intense sun.
Keep in mind that in winter, light intensity drops even in bright windows. This will slow growth of whatever you’re raising. If plants stretch, lean awkwardly toward the window, or grow pale, adding a small LED grow light positioned about 6–12 inches (15–30 cm) above the plants can make a big difference. In fact, your plants will appreciate the assistance!
Best Crops for Windowsills
Not all edible plants are suited to windowsill life. Corn? No way. Choose crops that are compact and fast-growing.
Some of the best options include:
· Herbs: Basil, chives, parsley, cilantro, thyme and mint for adding at-the-ready flavor.
· Leafy greens: Lettuce, spinach, arugula and Asian greens make having a salad easy.
· Microgreens: Just-germinated sprouts of radish, pea shoots, broccoli and mustard add flavor and nutrition to meals.
· Dwarf or patio peas: With a small trellis or even string, peas are indeed possible.
These crops stay relatively small, grow quickly, and tolerate container life well, making them ideal for a windowsill’s limited space.
Successful Seed Starting
After light, getting your seeds started properly is another key factor in raising crops on a windowsill. We can’t stress this enough: Always use containers with drainage holes. Even if you use recycled cups or small pots without holes, make your own holes! You want the potting mix to not hold excess water, and that really does require that those containers are able to drain.
Fill your containers with a high-quality seed starting mix, rather than a standard potting mix, which is specially formulated to support seed germination. Our Seed Starting Blend is a 100% organic combination of coconut coir, pine bark, and rice hulls that provides a balance between adequate moisture and water drainage. It also contains Worm Castings and an OMRI-listed organic fertilizer that provide young seedlings with a nutritional boost lasting upwards of 2-3 weeks after emerging.
Pro tip! Moisten the soil before planting. Most seeds should be planted about twice as deep as they are large, but very tiny seeds can simply be pressed into the surface. Water gently, then loosely cover containers with plastic wrap or a humidity dome until sprouts appear. As soon as seedlings emerge, remove the cover and move them into bright light right away.
Watering and Feeding
Watering a windowsill garden can be tricky. One concern is spilling water and damaging the sill and paint. Be sure to use a tray or dish under pots to protect surfaces.
Containers dry out faster than you’d think, so keep an eye on their water needs. Let the top inch of soil dry before watering again. If your tray fills with water, empty it so roots aren’t sitting in water.
After the first 3 weeks your seedlings will need additional fertilizer. A diluted organic liquid fertilizer every one to two weeks keeps herbs and greens growing steadily.
When to Transplant
Seedlings outgrow their first containers fast. It’s time to transplant when roots start poking out of drainage holes, soil dries out very quickly, or growth slows despite good light and care. Start to look for these things once the seedlings develop four to six true leaves. Simply slide the plants, roots and all, out of their pots and repot them into containers that are 1-2 inches wider than the previous container. No need to continue using a seed starting mix—use fresh potting mix such as our Container Blend Potting Soil, which provides excellent drainage yet holds just the right amount of moisture for those growing seedlings. Water well and return to the windowsill. Keep in mind your trays may need to be sized up once you use larger containers.
Harvesting
Harvesting is part of keeping plants healthy. Here’s a guide for how to harvest certain plants. Herbs: Cut herbs just above a leaf node (where the leaf connects to the stem) so the plant's branch becomes fuller. When harvesting, take care not to remove more than one-third of the plant at a time.
Leafy greens: Use the “cut and come again” approach, where you remove outer leaves and let the center continue growing.
Microgreens: These are usually ready when they are about 2–4 inches tall, often just one to three weeks after planting.
Pea shoots: Pea shoots are delicious! Cut these when they reach 4–6 inches tall. You might be able to harvest multiple times from the same plant.
Troubleshooting
Problems can occur even when growing indoors. For instance, leggy or stretching plants usually aren’t getting enough light. Yellowing leaves often means you’re overwatering or the pot has poor drainage. Slow growth can mean low light, cold drafts near windows, or lack of nutrients. Pests like fungus gnats or aphids sometimes appear out of nowhere, especially in constantly wet soil. Again, good drainage, moderate watering, and regular fertilizer additions go a long way in preventing multiple issues.
A few pots of herbs, leafy greens, peas and microgreens on a windowsill—even in winter—can transform mealtime into a meaningful moment. When you have a deeper connection with your food, it just tastes better! With good light, thoughtful watering, and timely transplanting, your windowsill can feed both your kitchen and your love of growing.
By Ellen Wells
