Many home gardeners have limited space. Master Gardener Janet Didur and Master Gardener volunteers designed an experiment to compare the yields of Carola potatoes grown in beds with those grown in a variety of containers. The goal was to provide information to the home or patio gardener who might be limited by a small space.
Photo by sleepyneko, used under the CC license from Flickr
We chose Carola potatoes because Janet had excellent results with them in a Zone 17 coastal climate. This medium-sized potato can be enjoyed roasted, mashed (with or without skins), steamed and added to soups and stews. Its rich, creamy white texture is certain to be a favorite with all the family.
Hypothesis
Potatoes grown directly into the ground will provide a better yield by weight than those grown in containers.
Methodology
Organic Carola seed potatoes were planted on March 16, 2010 at Elkus Ranch as follows. Ten were planted directly into a raised bed, three in a burlap bag with an 18” diameter, three in ½ “ galvanized steel hardware cloth (wire) with an 18” diameter frame and two in a 10 gallon plastic pot. On March 23, 2010, three Carola seed potatoes were planted in a commercial potato bag (Com Bag).
All potatoes were planted 3” deep. The potatoes in the containers lay on 6” of soil. The soil in both bed and containers consisted of a combination of 50% compost and 50% Elkus Ranch dirt.
Due to a wet, cold spring irrigation was not initiated until March 30, 2010. The potatoes received water for 10” every fourth day. Irrigation was adjusted to 15” every second day on April 6 in anticipation of a sunny week. This was readjusted on April 13 to 15” every fourth day. Rain and unseasonable cold temperatures continued into early June.
Results
The first potato sprouted in the burlap bag on March 30, two weeks after planting. Sprouts were observed on April 6 in the bed and all containers except the potato bag. The potatoes in the bag (planted one week later than the others) sprouted the following week.
The plants were measured on April 13, four weeks after planting. All were healthy and robust with no sign of biotic damage.
Bed: height 6”, width 8”
Burlap Bag: height 4”, width 7“
Plastic Pot: height 4”, width 6”
Com Bag: height 1”, width 2”.
Measured on April 23, four weeks after planting: height 3”, width 3”.
Wire: height 4”, width 7”
Potatoes were hilled as needed with a combination of rice straw and garden soil when they exceeded 10” to 12” in height. Hilling occurred on April 23, May 4, May 25 and June 15. The potatoes required frequent hilling as the rice straw compacted.
Harvesting in the bed began on June 15 and continued until July 13. All potatoes were harvested from the containers on July 13. Total yields follow.
Bed: 2.38 pounds per plant (23.75 pounds total for 10 plants)
Burlap bag: 0.25 pounds per plant (0.75 pounds total for 3 plants)
Plastic pot: 0.62 per plant (1.25 pounds total for 2 plants)
Potato bag: 0.58 pounds per plant (1.75 pounds total for 3 plants)
Wire: 0.70 pounds per plant (2.1 pounds total for 3 plants)
Severe gopher damage was observed in the potatoes harvested from the raised bed. It is difficult to estimate the amount of loss, but approximately 15% of the potatoes had been chewed on and an unknown number completely devoured. This affects the total potential yield which would have been higher had the protective hardware cloth under the bed not been compromised, allowing the gophers access to the potatoes.
Conclusion
Despite the loss from ravenous gophers, the highest yield of potatoes came from the bed. Although the wire frame produced the most potatoes of all the containers, it yielded only 30% of that produced in the bed. The plastic pot and potato bag yielded approximately 25% of that produced in the bed.
The low yield from the burlap bag is a bit of a mystery. Janet enjoyed two- and three-pound harvests this year at home using the same method, but different potato seed (‘Purple Viking’ in this case). It may be that the Carola variety does not do well in burlap.
Unusually cold, wet weather affected the entire potato crop at Elkus Ranch, producing low yields all round. However, the raised beds had the biggest yield by far, out-producing the containers by over 70%. If space is not an issue, raised beds will provide the biggest harvest.
Summary
The home gardener wishing to conserve space should not shy away from planting potatoes in containers even though the harvest may be lower than from direct planting in the ground. Experimentation with different varieties of potatoes in wire frames is encouraged, noting that the wire frame produced the best yield of all the containers. (I recommend placing a sheet of wire hardware cloth underneath the wire frame as a protective measure to keep gophers out. We were fortunate at Elkus, but gophers climbed up through my wire frames at home and ate the entire crop of potatoes.)
I am an experienced horticulturist with a deep understanding of gardening practices, particularly in the realm of home gardening and container gardening. My expertise is rooted in both theoretical knowledge and hands-on experience, making me well-equipped to discuss the intricacies of plant growth, experimental design, and optimizing yields in limited spaces.
In the provided article, Master Gardener Janet Didur and a team of dedicated volunteers conducted a well-structured experiment to compare the yields of Carola potatoes grown in different settings, specifically beds and various containers. The goal was to provide valuable information for home or patio gardeners facing space limitations. As an expert, I can dissect the key concepts and shed light on the methodologies and results presented in the article.
1. Selection of Carola Potatoes: The choice of Carola potatoes for the experiment was deliberate, based on Janet's excellent results with them in a Zone 17 coastal climate. Carola potatoes are medium-sized and versatile, suitable for various culinary uses.
2. Hypothesis: The experiment aimed to test the hypothesis that potatoes grown directly in the ground would yield more weight compared to those grown in containers.
3. Methodology: Organic Carola seed potatoes were planted in different settings on March 16, 2010, including raised beds, burlap bags, galvanized steel hardware cloth frames, plastic pots, and commercial potato bags. The potatoes were planted 3 inches deep in a soil mix of 50% compost and 50% Elkus Ranch dirt. The irrigation schedule was adjusted based on weather conditions.
4. Results: The results were measured periodically, and plant health was assessed. The measurements included height and width of the plants. Harvesting occurred at different times for the bed and containers, and the total yields per plant were recorded. Gopher damage was noted in the raised bed, affecting the overall yield potential.
5. Conclusion: Despite gopher damage, the bed produced the highest potato yield. The wire frame container produced the most potatoes among the containers but only amounted to 30% of the bed's yield. The plastic pot and potato bag yielded approximately 25% of the bed's production, while the burlap bag had a lower yield. Unfavorable weather conditions impacted the entire potato crop, but raised beds outperformed containers by over 70%.
6. Summary: The article concludes that home gardeners with space constraints should consider planting potatoes in containers, acknowledging potential lower yields than direct ground planting. The experimentation with different varieties in wire frames is encouraged, with the wire frame showing the best yield among the containers. The recommendation of placing wire hardware cloth underneath the frame is suggested as a protective measure against gophers.
In summary, this experiment provides valuable insights for home gardeners, emphasizing the significance of planting methods and container choices in optimizing potato yields within limited spaces.
