Windowsill Gardens

The following was found at Annies.com, written by the Center for EcoLiteracy.

A windowsill garden is a delightful addition to a classroom, a kitchen, or a balcony. The natural beauty of plants provides a splash of color and stimulation. Plants growing in our homes and classrooms remind us of our inherent connectedness with the Earth as they provide us with clean air to breathe. Just as a kitchen windowsill overflowing with herbs or flowers inspires us to cook more creatively, a windowsill garden in a classroom evokes curiosity and daily observation. Not only do indoor gardens offer a rich context for learning, they are resourceful options for schools with limited space, extreme seasonal weather conditions, and minimal funding.

ADVANTAGES

Manageable If you don’t have an ideal place for a traditional, in-the-ground garden, if the seasons are too extreme to grow outside year-round, or if you want to start plants from seed and don’t have a greenhouse, a windowsill garden could be perfect for you. They take up very little space and can still be quite productive, if plants are chosen and cared for properly. Windowsill gardens grow well year-round as long as they have plenty of light.

Great for Cooking Delicious herbs, edible sprouts, and baby lettuces can thrive indoors.

Convenient to Classroom Windowsill gardens are invaluable instructional tools for hands-on learning about life systems without having to leave the classroom.

Brings Outside Indoors Windowsill gardens can serve as bridges to the outside world, bringing the pleasures of nature inside as a calming focal point.

DISADVANTAGES

Sometimes Difficult to Transplant Outdoors Plants will often grow “leggy” — or grow too tall too fast — developing weak stems as they reach for light. Consequently, plants that are started in windowsill gardens can be too weak to be transplanted outdoors.

Hard to Water Properly Windowsill gardens are difficult to water properly. Small containers quickly dry out over weekends and holidays, and students tend to enthusiastically overwater small pots in the classroom. Also, if the plants don’t get enough direct light and the temperature fluctuates greatly, they will not thrive.

Can Easily Outgrow Container Most large vegetables and flowers, such as squash, beans, corn, tomatoes, and sunflowers, will sprout in a windowsill garden, but will quickly outgrow their containers and need more full-spectrum sunlight.

Limited Planting Options Windowsill containers will likely not be deep enough for taproot or root vegetables, which also don’t like to be transplanted.

DESIGNING THE GARDEN

1. Choosing a Location

Before you settle on a place to establish your windowsill garden, have the kids observe how the sunlight moves through the classroom, keeping a record of their observations for at least a week. They can repeat this each season and notice how the sun’s arc changes throughout the year.

Determine which direction the windowsill is facing. The windowsill garden will need at least 4–6 hours of sunlight on most days. In the Northern Hemisphere, windowsill gardens facing north will generally not get quite enough light to grow healthy plants from seed. However, other shade-tolerant indoor plants will do fine if properly cared for. East-facing and west-facing windowsills are the best bet, as they tend to receive the right amount of direct sun. Windowsills that face directly to the south can flourish, but they must be monitored carefully since the light may be too intense and the soil in the containers may dry out quickly.

2. Selecting Materials

Decide if the plants are intended for eventual transplanting to a larger, outdoor garden or are going to grow to maturity inside, and if you and the kids want to grow flowers, vegetables, herbs, or indoor houseplants. Think about how students will interact with the garden. Will they be moving the garden from the windowsill to the middle of the classroom, where it is accessible and visible to all, or to students’ desks? These factors will help you decide what kinds of containers to use.

If the garden will be moved from one classroom to another, consider using rigid trays and containers to minimize problems in transportation. Also, a cart or table with casters would be useful for moving the garden to different rooms or through the hallways.

If you plan to use the windowsill garden primarily for germinating seeds, small containers work the best. Six-cell packs from a nursery work well, as do empty egg cartons or eggshells.

For growing plants such as herbs and lettuces that you will eventually transplant outdoors, use a medium-size container. A 2 x 2 or 3 x 3 inch pot or an equivalent size is ideal. Consider unusual but attractive containers like baskets, coffee mugs, or empty tea tins.

If you plan to keep the plants indoors throughout their life cycle, choose a larger container that is at least 6 x 6 inches. Reused nursery pots and repurposed flower vases work well in windowsills. A miniature version of an outdoor container or raised bed, with a bottom and drainage tray, will work well, such as a small wooden box.

Whatever receptacle you choose for your windowsill garden, be sure that water can drain away from the plants. Punch or drill holes in the bottom and place a plate underneath the receptacle or place pebbles in the bottom so water will drain through them and away from the roots. How will water that drains out of the containers be captured and not cause damage to the windowsill, furniture, books, and other surfaces?

3. Selecting Soil

For windowsill gardens, it is easiest to use an organic soil mix from a nursery. When sprouting seeds, use a lightweight seed-starting mix. When filling a container for growing lettuces and/or herbs, a richer potting mix is most suitable.

4. Choosing Plants for the Garden

If you are planning to use the windowsill for germinating seeds in containers, consider starting with big seeds such as beans, corn, sunflowers, or nasturtiums. Keep in mind that these crops will quickly outgrow their containers and will need to be planted in an outdoor garden within a couple weeks of germinating.

If you want to grow seeds to maturity in the windowsill, consider growing herbs (dill, parsley, cilantro/coriander) as well as lettuces and baby greens such as arugula and mâche.

5. Maintaining a Windowsill Garden

Maintaining your windowsill garden is like maintaining an outdoor garden under a microscope. The soil moisture should be checked every day. If you are sprouting seeds, you can water a little bit every day to keep it moist. Once the seeds sprout, check the moisture with your finger to see if it is cool and moist below the surface, and then decide if it’s time to add more water. Windowsill gardens that receive lots of direct light need more water than those exposed to diffused light.

If you are growing herbs, or lettuces and baby greens, make sure to harvest them when they are ready to eat.

If you are sprouting seeds with the intention of transplanting them to a larger outdoor garden, make sure to wait until the plants have their first set of “true leaves” before disturbing them. Then, place the young starts outside for 4–7 days in their original pots before planting them in the garden. This is called “hardening off” and will allow them to gradually adjust to the outdoor conditions.

Kids also enjoy vermicomposting, so consider setting up a worm bin in the classroom for disposal of organic waste and use it to replenish the nutrients in your windowsill garden.

WINDOWSILL GARDEN MATERIALS CHECKLIST

You will need at least one of the following:

• Small container for starting seeds, such as re-purposed cups, egg cartons, egg shells, used nursery cell trays, nursery pots, tea tins, or coffee mugs

• A planter box or tray that fits the windowsill space

• Glass or plastic sprouting jar (for growing edible sprouts)

You will also need:

• Low-nutrient potting soil

• Compost to add to the soil each time you plant

• A plate or tray to catch the water that will drain out of the containers

• Water

• Small watering cans

• Seeds