Patio Gardening - May 12, 2010
Jeff Schalau, Associate Agent, Agriculture & Natural Resources
University of Arizona Cooperative Extension, Yavapai County

People are hungrier than ever for useful and labor-saving gardening information. Gardening catalogs and web sites are full of other gadgets designed to make gardening foolproof. Our “as seen on TV” culture promotes these products and practices making them seem effortless and perfect in every way. I am often asked my views about growing systems like “upside down tomatoes” and EarthBoxes. Below, I discuss these two systems and share my views about their utility and sustainability.

Using upside down pots hanging from a stand to grow tomatoes is a current garden fad. Potting soil is placed in the upside down container with tomato plants growing from the bottom of the pot. This pot is suspended from a stand or a hook. Various claims are made about the merits of the system, but I think it’s attractive to people because it is different and it touted as convenient and trouble free. However, you must support 40+ pounds of artificial soil media from a stand and keep it irrigated (as it the root ball is exposed to heat and dry air). It is also heavy and requires some lifting and hardware to support the upside down pot. In addition, the use of soilless growing media also has issues which I discuss below.

EarthBoxes are a patented container gardening system that has a water reservoir and a screen which relies on capillary action to wick water upward. They have a premeasured fertilizer strip and come with a plastic sheet mulch to minimize evaporation losses. The EarthBox requires 2 cubic feet of soilless growing media and seems to be an improvement over other, more simplistic containers (five gallon buckets with holes in the bottom. Accessories can be purchased such as trellises, automatic watering systems, and casters that allow it to be moved from place to place. While the well-designed, EarthBoxes also require soilless growing media.

Both systems are seeking to simplify home gardening and/or provide alternatives for people without regular garden space. Many home gardeners have used them or created their own upside down pots. The bloggers discussing these upside down tomato growing systems have given them mixed reviews. EarthBoxes are more straightforward and people seem to be successful and satisfied with their performance. I would like to hear from readers about local success of either of these two systems.

Soilless growing media has definite advantages, but there are also potential problems with it. Soilless growing media has been a great boon to home gardening and the nursery industry. Native mineral soil contains microbes: beneficial and benign species as well as pathogens that can cause plant diseases. Soilless growing media is often steam sterilized and therefore largely free of pathogens. This is great for starting seedlings and other uses where plants are most vulnerable and disease is a real concern.

One of the major components of soilless growing media is peat moss. Peat moss is mined from peat bogs. Consisting primarily of Sphagnum species, peat moss has an amazing capacity to hold water like a sponge, slowly releasing it as the surrounding soil dries out. Peat moss is a natural resource that accumulates at about ¼ of an inch per year. Peat harvesting involves the removal of deep layers of peat that have literally taken centuries to accumulate. Unfortunately, there is no economically realistic, environmentally friendly way to harvest peat moss and the current rate of peat removal is not sustainable. However, the horticulture industry is starting to explore sustainable alternatives to peat moss.

Convenience is often a good thing – but, gardening is about monitoring and nurturing your plants during the growing cycle. Automated irrigation and premeasured fertilizers are convenient, but they only serve to distance the gardener from the garden. Gardening requires close observation of your plants and making adjustments to irrigation and plant nutrition. So, if you use these patio gardening systems, remember to monitor your plants and watch for pests.

The University of Arizona Cooperative Extension has publications and information on gardening and pest control. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 ext. 14 or E-mail us at and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site:

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Arizona Cooperative Extension
Yavapai County
840 Rodeo Dr. #C
Prescott, AZ 86305
(928) 445-6590
Last Updated: June 21, 2010
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