Easy Steps to Design a Container Garden on a Patio or Balcony
To anyone who likes to have a little green leafy life around them, having to move into an apartment or condo, where the only outdoor space you have is a balcony or patio, can feel, well, sterile. Sure, we see photos of leafy tomato plants growing on balconies here and there in the city, but honestly, for every one of those balconies, there's another 20 bare concrete spaces.
Even if you think your patio is a hopeless concrete wasteland where nothing will grow, you might be able to use a few tricks to create a little green space by creating a container garden.
Determine your sun exposure
In case you are new to gardening, take this first step - determine your sun exposure.
The first thing to do is....nothing! Observe for a while just how much sun your patio/balcony gets. Check the sun exposure of your patio.. The quantity and quality of sunlight that your plants receive is dictated by the direction it faces. Remember your fourth grade science? In the northern hemisphere, the sun remains in the southern sky all year long. The sun is lowest in the southern sky in the winter, and nearly overhead in the dead of summer.
For that reason, a patio that faces south (i.e., the patio with a southern exposure) will have the best sun condition for sun-loving plants, since it will receive sun for a large part of the day. If your patio faces north, it gets no direct sun. Eastern exposures gets cool morning sun; western gets hot, intense afternoon sun. Usually our homes don't face any of these directions directly, and so the amount of actual sun exposure differs from these simple examples, and due to obstructing trees or buildings. The best thing to do is note where the sun sets and rises with respect to your patio or balcony, and if anything blocks the sun's rays.
It would be ideal to wait until one season passes into the next, to see how the sun changes with the season. A shadow you don't expect suddenly appears, because the sun is lower in the sky in the winter than you expected, or the spot you thought was so sunny in the winter is suddenly in shade when a bare tree you didn't notice leafs out in the spring.
Who wants to wait that long, though? Not me, and probably not you. It's likely that the changing seasons will have some surprises for you, but the same strategies described can be employed to take care of these seasonal changes, too.
If your patio doesn't have the sun exposure for the plants that you would like to have, see if these tricks will help:
Not enough sun? Well, you can't make more sun, but is the sunlight simply falling over your plants' heads? Check if there are sun rays a couple of feet above your plants, and if so, boost them into the sun by putting an upside down pot underneath them, or hang them for a while.
Don't have a ceiling to put in hooks? Here's a work-around – stand a $15 shepard’s hook in a large pot and pack in soil until it's sturdy. Voila – two hooks from which to hang potted plants. You could even plant little annuals in the soil at the base, if the light works out for you. The deeper the pot, the better. I did this to hang a bird feeder, using a plastic pot and sand instead of soil. It's study enough for the little feeders, but I'd definitely have to get a deeper pot and do a better job to anchor the hook if I wanted to hang planters.
Make a sunscreen to create shade
If you just don't get sun, no matter how high you place your plants, you simply have to settle for shade-loving plants. Luckily there are plenty of shade plants, and they tend to be pretty tough customers that hang on with little care. Shop the houseplants section – they all survive in low-light environments.
If you have too much sun, or maybe you just get the western sun blazing into your patio all afternoon, try the following tricks to make those sun rays more manageable.
Depending on the patio's size, you can try planting some dwarf trees in pots to screen the direct sun, and position other plants in the dappled shadows of the trees. There are many dwarf fruit trees sold in nurseries these days, and fruit trees generally prefer full sun. Even dwarf trees are happier in the ground, so I recommend asking a nursery worker which ones are best in pots. There are even “ultra-dwarf' fruit trees that are supposed to be limited to about four feet in height.
I used this trick of shading with trees and took it a step further on my own patio. I'm lucky to have a planter (which was filled with overgrown heavenly bamboo when I moved in. It is like iron! Don't plant it unless you love it and know you'll never get sick of it!) I planted a dwarf pomegranate tree in the planter, and the tree is now about five feet tall. Pomegranate trees are deciduous (they drop their leaves in the winter). I recently brought home two Pacific blueberry shrubs/vines, only to realize later that the spot I planned to put them in is probably too hot and sunny in the summer. I positioned them instead on the north side of the pomegranate tree. In the winter, it is cool, the tree is bare and the shrubs get sun most of the day. But by the time summer comes and the pomegranate tree has regained its leaves, the shrubs will get the morning sun, but will be shaded by the pomegranate tree later in the day.
Select your sun-screening trees with the amount of shade you want in mind. If you want to grow plants that need dappled shade, choose dwarf trees with small leaves that create dappled shade, like a pomegranate. You could thin the tree out by pruning if the shade gets too heavy. If you want more complete shade, choose trees with larger leaves, and/or heavier canopies, like dwarf avocado or citrus trees. Large grasses like bamboo or shrubs might work even better than the dwarf trees. Ask for advice at the nursery.
Very large pots, or potted plants set on upside down pots acting as pedestals, can also be used to shade plants that cannot tolerate direct sun, if you have a sunny patio. Even a western exposure, where the sun is blazing in the afternoon, can be tamed to create varying amounts of shade using strategically-placed pots planted with small trees, sun-loving shrubs or large perennials, or even a patio table umbrella.
Plants in containers have special needs
Another thing to be aware of is the special needs of plants in containers. The Theodore Payne Foundation web site (dedicated to growing California native plants, http://www.theodorepayne.org) calls plants in containers “like astronauts in space,” needing special care to keep them alive in a special environment. It's a great analogy to keep in mind.
With patios and balconies, there are a number of special considerations to account for, when building a patio container garden. One is fertilizer: Since they cannot spread their roots beyond the container to access nutrients in the soil, plants in containers may need more frequent but lighter applications of fertilizer. As for replacing the soil in a pot, I would try it out only on the hardiest plants first and go from there.
Another consideration is radiant heat from concrete or stone walls. Remember that a plant in a pot sitting in direct sun against a stone wall, or surrounded by concrete is even hotter than the same plant sitting in direct sun but surrounded by other plants, away from concrete. Best to put plants that not only love sunlight, but also like heat, in places like that.
Similarly, some plants are accustomed to their roots being kept cool by the earth, and having their pots, especially plastic or metal pots, being struck by direct sun, will damage their roots and cause them to fail. If you have sun-loving plants in direct sun, and they are not doing well, consider that the problem might be that their pots need to be shaded to keep the roots cool. Try positioning them behind taller pots, where their pots will be shaded but their leaves will still get sun. Another thing to try is planting them in larger clay pots, which might keep their roots cooler.
As for watering, we're all familiar with the warning that clay pots dry out quickly. It is possible that even drought-tolerant plants, if planted in clay pots, will do better with more watering than what is recommended, since the soil in the clay pot will dry out, whereas it would not if planted in the earth. Monitor the soil in your pots – the quick and truly dirty way is to stick a finger in the soil at least two inches, and if it's dry, adding some water. Glazed pots don't dry out as quickly.
Creating a container garden on a patio takes a little strategic planning and attention to details like radiant heat and adjusting water schedules to account for faster drying, but it can be done. Every gardener has plants that fail, and experimenting and tinkering is part of gardening. But understanding the factors, and how to compensate for them, will allow you to succeed.