Years ago a friend told me I had a pot problem. Not that kind of pot, but receptacles for growing plants. She was right. My plants-in-pots collection has only continued to grow. I garden in small pots and very large pots. My small succulents are in small pots, and rhododendrons that really should be in the ground are in very large pots. A hand truck is an important piece of equipment for my garden. Since I am an enthusiastic plant propagator, smaller utilitarian plastic pots also are essential.
There are many advantages to gardening in pots. Plants can be tucked into places where the sun or shade is just right, such as a porch, patio or deck, under a tree, or where the site is a good place to display a specimen plant. Pots can be moved to the shade during hot weather. In a pot the most appropriate soil for a specific plant can be supplied. For example, vegetables and other annuals need a richer soil and more water to support faster growth. Some perennials and succulent plants need a less rich soil and faster drainage than plants that have to do their thing in just one season.
Specific gardening techniques are needed for successful cultivation in pots. Pots must always have at least one drainage hole. Pots must be watered regularly, before the soil dries out. In hot weather watering is essential morning and evening. Our experience during the summer heat waves is that moving some pots to shade and extra watering for the most exposed pots made it possible for them to tolerate the extremes. In winter smaller pots should be placed on the ground or moved to warmer areas when a significant freeze is predicted. Keep an eye on root growth. Plants can easily get pot-bound and fail if they are not moved to a larger pot. “Potting up” is best done in the spring.
Because pots provide a smaller growing area, more attention should be paid to the soil. The goal is to use soil that provides nutrients but has faster drainage than garden soil. Use a high-quality potting soil available at nurseries such as Garden Fever or Portland Nursery that balances drainage, moisture retention, and nutrients. I make my own potting soil using the high-quality potting/raised-bed soil from the nurseries and adding some coarse sand, a small amount of ¼”-ten gravel for drainage, and a balanced slow-release fertilizer. I fertilize established pots every spring. A good source of the sand and gravel is Oregon Decorative Rock on NE Columbia Boulevard.
We enjoy growing and eating vegetables. The warmest and sunniest spot in our garden is the parking strip next to the driveway. There we have quite large plastic pots in which we grow the heat lovers, tomatoes and peppers. In this environment watering can be needed twice a day. The plants survived the June heat wave with just minimal leaf burn. Fruiting vegetables must grow and produce in a short time so adding vegetable/tomato fertilizer is essential at the beginning of the growing season.
Pots are great for “plantaholics” who can’t live without a certain plant but don’t have an immediate appropriate site in the garden for planting. This is an advantage or disadvantage depending on your viewpoint. Pots can also be very beautiful and quite varied in appearance. Once you start acquiring pots, you need more, especially if you have a friend who is a potter. My mother was a potter and made lovely pots for plants. I am still using her pots 40 years later.
Terra cotta and ceramic pots are heavy, a definite drawback. Lighter, attractive plastic pots have become readily available over the years at nurseries and garden centers. My latest discovery was “bonsai” pots made of plastic. Plastic pots are no longer just nursery stock-growing pots.
Several years ago I was inspired by a friend to make planters out of Styrofoam fish shipping boxes. I carved and textured the outsides of the boxes and then painted them. It has turned out that the Styrofoam planters are great insulators from cold and heat. During the recent heat waves the watered plants in Styrofoam did quite well, even in the sun. I have not lost a plant to freezing in Styrofoam planters. The downside to Styrofoam, even if it is covered with a thin paint and concrete slurry, is that they can easily be damaged. A touch up with paint works wonders. When moving a larger Styrofoam pot, it is a good idea to place a board underneath it and have a helper.
I have small carnivorous plant gardens in large shallow pots. The pots are placed in large 3- to 4-inch-deep plant trays that supply the water that is constantly required. This could also be seen as a disadvantage since daily topping up of the tray is essential in summer. They are doing well and the time is coming when they need to be divided and the extra plants given away to other enthusiastic gardeners.
There are huge varieties of interesting plants, and plant nerds want them all. Some plants, like the carnivorous, have exacting requirements. Using pots of different kinds and sizes allows all gardeners to explore and nurture a huge palette of plants.