Those of us who are confirmed apartment- or condo-dwellers know that urban gardening can sometimes be a bit of a challenge. Floor or table space is usually limited, and window boxes can only go so far.</br></br>Lots of people are choosing unconventional places for gardening to compensate for small spaces, and vertical gardens are a fun and functional way to add a touch of greenery, <a title="SF Gate" href="http://homeguides.sfgate.com/effect-plants-indoor-oxygen-levels-86266.html" target="_blank">improve air quality</a> and even live more sustainably with homegrown produce.</br></br><strong>How does vertical gardening work? </strong></br></br>There are a few different methods for <a title="Wall Gardens" href="http://www.atgstores.com/outdoor/curb-appeal/planters/type/wall/" target="_blank">creating a vertical garden</a> and, despite their professional, high-end appearance, they are all relatively simple to create.</br></br>The main element that any wall garden needs is a surface where the plants can take root. <a title="New York Times" href="http://www.nytimes.com/2010/05/06/garden/06vertical.html?_r=2" target="_blank">Narrower wall planters can use spongy materials</a> such as felt or Spanish moss to give roots an easy way to take hold while using less soil. This makes it so the planter needs less horizontal space, keeping the vertical garden from protruding too far from where it's mounted.</br></br>On the other hand, a shallower base may result in less developed roots, which means they might not thrive for as long. So, it’s up to you to choose how to balance aesthetics and plant hardiness.</br></br>If you’re not up for the DIY project of building a wall garden from scratch or the challenge of determining the proper depth for root growth, there are a number of prefabricated wall planters and panel systems available. Vertical gardening panels<strong> </strong>can offer a large amount of planting space in a relatively small area. They also allow plants to grow in the same way they would in a pot, but in a configuration that makes it easy to achieve a green wall effect.</br></br><strong>What plants are best for vertical gardens?</strong></br></br>When it comes to plant species, vertical gardens have essentially then same restrictions as potted plants. Outdoors, you can grow just about any plant that has enough space to establish a healthy root system. Indoors, consider the roots as well as the amount of sunlight your space receives.</br></br>Of course, you can select plants based on their appearance in addition to considering the environmental factors. This is where you can really customize the appearance of your green wall.</br></br>Do you want plants that stay tidily confined to their spots? Try flowers such as geraniums and lavender, or go with something for the kitchen like herbs or strawberries. Or, are you looking for a wilder, draped look that completely hides the planter? Ferns, ivies or even tomato plants are great choices for more coverage.</br></br>You can also mix different heights, textures and colors of plants to create a pattern or design on your wall.</br></br><strong>What else should I know about vertical gardens? </strong></br></br>Whether you’re creating your vertical garden indoors or out, be sure the wall that you’re using is sturdy enough to hold your garden. Soil can be very heavy, so it’s important to make use of wall studs or structural supports.</br></br>Also, make sure you look into what kind of irrigation your vertical garden accommodates and always ensure there is a moisture barrier between your garden and the wall to avoid water damage.</br></br>Follow these recommendations and you’ll be well on your way to having a beautiful, thriving green wall in your own home or yard with your new vertical planter.