Irish Potatoes

Karen Cambre, Sharpe, Kenneth W.

News article for January 15, 2018

In south Louisiana when I talk about the dormant season, it is not uncommon for people to tell me that we never have winter. I would say that we are having a winter this year.

We have started a cold New Year, but a fresh start and anticipation of better things to come. Many of us have resolved to do better. We want to eat healthier, exercise and improve in lots of areas.

One area that those of us who like to grow plants can improve is taking soil samples. If you have had garden, lawn, landscaping or pasture problems, the first line of defense is to take a soil sample and see if your soil has the proper nutrients for plants to grow. It is as important as your doctor taking your temperature or running a routine blood profile. Those levels that we find can tell us if you have a problem or can help us pick up on a trend and prevent a problem.

I would suggest that you take a soil sample every 3-5 years just to be on a good “wellness” program. If you are having problems, we may need soil testing more frequently.

In order to run a soil test we need a pint of soil taking randomly throughout the growing area. Use a shovel or soil probe to go down about 2 inches deep and take a small amount of soil and put that in a bucket. Continue taking soil from 15-20 different spots within the growing area and putting them all in the same bucket.When you have taken enough “subsamples” to cover the area, mix all of your subsamples together with your hand. From this mixture take 1 pint of soil and send that in for analysis. That sample can be brought to the County Agent’s office along with a check for $10/sample. The LSU soil testing lab has about a 5 day turn around once they get the sample.

The report that you receive will tell you the soil pH. In addition, the lab will add lime or sulfur to your soil so they can calibrate rates and will give you an individual recommendation on how to correct any pH imbalances. Your report will also give levels of phosphorous, potassium, calcium, magnesium, sodium, sulfur, copper and zinc. Recommendations are included on which fertilizers to use to correct any deficiencies.

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Armed with that information you will be ready to plant the earliest spring crop you can plant, Irish potatoes. I know it sounds early in light of our weather but the best yields are obtained from potatoes that are planted from January 15th to February 15th. Irish potatoes have optimum germination in soil temperatures of 45-50˚F.

The biggest challenge is getting dry enough to work the rows and plant. Once you make up your rows, fertilize according to soil sample results. In the absence of soil result information, use 8-10 pounds of 8-8-8 fertilizer per 100 feet of row prior to planting.

Bacterial rot, which emits the rotten potato smell, can be a problem in wet years, so cut seed potatoes and let them heel over for several days before planting. Cut seed into hen egg size blocks with at least one eye in each seed. Once heeled, seed are planted at 4 to 6 inches deep and every 12 inches within the row. Seed are then protected from the cold and even if foliage appears and is nipped off, the plant will regrow.

Red Lasoda is the most popular variety planted and usually available. It is a round, red skinned potato that should be ready to harvest approximately 100-120 days after planting. Other red varieties to try, if available, would be Red Norland or LaRouge. If you like white skinned potatoes, try Kennebac which is oblong. LaChipper and Atlantic are round and white skinned.

For more information on these or related topics contact Kenny at 225-686-3020 or visit our website at

5/8/2018 7:39:58 PM
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