How to Grow in a Window Box for Beginners

Last Updated on April 27, 2022 by Ellen Christian

Have you wondered how to grow in a window box? Check out these window box tips and learn more about the best window box flowers.

I hear a lot of people complaining that they can’t have a garden because they don’t have enough room on their property or they live in an apartment with no yard.

How to Grow in a Window Box

While it would be difficult to have a whole garden in a window box, you can certainly grow flowers, herbs, and a few types of vegetables without much difficulty providing you have enough sun.

Even if you do have a yard for a garden, using a window box for your flowers will help eliminate time spent weeding. 

What can I plant in a window box?

Window boxes work great for plants with shallow root systems. There isn’t a lot of room in a window box, so the plants you choose will need to be relatively small with shallow roots.

You don’t want to choose plants that need to vine up a trellis since they will probably not have enough room to grow properly. Avoid top-heavy plants like larger varieties of tomatoes.

Plants that need a lot of room to grow down like carrots will also generally not do well.

What vegetables can I plant?

Vegetables that will grow in a window box include things like leaf lettuce, arugula, spinach, radishes, chives, leeks, or scallions. Most herbs will do well in window boxes.

And, I particularly recommend parsley, sage, oregano, thyme, and basil.

Strawberries do quite well in window boxes and are beautiful to look at when the flowers are in bloom and the berries are ripe. Almost any type of annual flower will grow well in a window box.

If you like edible flowers, you can add in some pansies or Johnny jump-ups to help “disguise” your veggies.

How to arrange a window box

To begin, spread the moist potting soil evenly in your window box. Add in a few handfuls of organic compost to give your plants extra nutrition. Tap the window box on the ground a few times to be certain that the soil has settled evenly into the box.

Fill the window box to almost a 1/4 inch to the top. Plant the seeds according to the directions on the packet and press down gently.

You will want to be sure that the soil is damp but not soggy at all times. It’s often easier for me to start with seedlings rather than seeds.

Make sure that the variety of plants that you choose will fit in the window box at its full-grown size. You may want to look for miniature or dwarf varieties to be certain you will have enough room.

Plant vegetables and herbs with similar soil and watering requirements together in the same box.

How many plants per window box?

First, if you are beginning with plants and not seeds, remove the plants from their containers and dig a small hole in the potting soil. Gently place the plant in the hole. Refill the area with potting soil.

And, water well.  You want to leave enough room for the plants to grow in your window box because they won’t grow well crowded.

How often should you water window boxes?

You will need to make sure you add in enough fertilizer to the soil you use in your window box. And, take care to see that it has enough water.  

A window box planter will need extra water because the soil will dry out quicker than the soil in your backyard. So, a good rule of them is twice as often as a regular garden.

So, follow the same spacing guidelines to grow in a window box as you would in your garden. How many plants per window box will depend on the size of the plant and the size of your window box.

Using a hydro globe is a fantastic way to make sure your window box gets enough water because that can be a challenge.

The best place to hang planters

Hang your window box from a south-facing window. Most window boxes come with mounting hardware. Check out these flowers that need full sun to see what will grow best.

Some window boxes will screw into the wood frame around the window. Others will including mounting hardware that allows it to hang over the window ledge.

Or, if you want to make your own window box, this post from Catz in the Kitchen will show you how.

Finally, once your plants begin to grow, be certain to use what you’re growing to keep the size manageable. Harvest lettuce and spinach from the outside to the center.

Trim fresh herbs as you need them, and keep them pinched back to avoid flowering.

If you’d like to have a larger garden and you just don’t have the room, you may want to learn about how to start a community garden. Or, try some wild foraging.

If you do have the room, learn more about planting trees. So, what would you like to grow in a window box?

If you’d like more gardening inspiration, take a minute to visit DIY Idea Center for National Gardening Month. And, be sure to sign up for their updates.