Sweet Potato Taste Test

[seaeagle]

Here are tips for growing sweet potatoes from Sand Hill. Also some good info for growing in cooler climates.I think I posted this before but doesn't hurt to post it again since it is spot on.



SWEET POTATO TIPS FOR SUCCESS



First: Forget what climate zone you are in. That has nothing to do with growing annuals, that is for over wintering plants. Parts of coastal Alaska are in zone 7b. Here in Iowa we are in zone 4b. If we set out plants in the garden on the same day in both places it is almost certain the folks in Alaska will not have anywhere near the success we will have here.



Second: Do not set the plants out when it is very cool. They hate cold and just sit there shivering and waiting for heat. Do whatever you can to make it warm and toasty for them and they will reward you.



Third: You do not need lots of roots on the slips when you plant them to be able to insure success. The more roots the more stress when transplanting and the more they will be stunted. The key when setting out the slips is to have very few roots and keep them as wet as possible in the garden for the first 7 to 10 days. Then back off on the water and they will go crazy. The worst possible thing you can do upon receipt of the slips is to pot them up, wait a few weeks and then transplant to the garden. You will have lost a good 2 weeks of positive growth and will have given them two chances to slow down. The more you slow them down the less yield you have. The more times you transplant them the more non-uniform roots and the less roots you will get. You will frequently get one ball shaped twisted root from plants that have been repotted in pots and then transplanted into the garden.



Fourth: This is the most important thing when it comes to sweet potatoes. It is the heat units that determines success, not the number of days nor plant zone, but heat units. I have been an avid weather observer for over 40 years and have files of weather data to go with files of planting data. A few years ago , thanks to the help of one of our workers, I was able to put the two sets of data together and arrive at some conclusions that I had already suspected, but had never had the time to confirm. It takes about 1200 heat units for our early varieties to reach a decent crop of usable size roots. I use the term usable size as I think for many a sweet potato the size of a nice fat bratwurst is about the best size for keeping and for baking. Bigger than that is okay, but they do not sprout as well nor keep as well because they suffer from bruising much easier. The question you must then ask yourself is: “How is 1200 heat units determined?” I offer the following examples. To get heat units you take the day’s high temperature (maximum) and the day’s low temperature (minimum) and add them together. Then divide by 2 and subtract 55 from that. That gives you the heat units.



Example 1. Daytime high (maximum) 75 deg. F, night time low (minimum) 45 deg. F. Add those together and divide by 2 you get 120/2 or 60. Subtract 55 and you get 5 heat units. If that is your typical summer, then you will need 240 frost free days to get a crop. It doesn’t take a genius to realize that if you have summertime days like that, you are probably not going to have 240 frost free days because that is 8 months.



Example 2. Daytime high of 90 deg. F, night time low of 70 deg. F. That gives you a heat unit for the day of 25 which is just about perfect for maximum growth. Heat units per day greater than 25 seem to have more of a negative impact because of the massive amount of water lost through transpiration. If you can keep 25 heat units a day, then you only need about 48 days to get some useable roots. This is pushing it a bit as there are some limits to daily plant growth. The best growth I have ever seen here is planting around July 18 and having a decent crop by our first frost of October 2, which is about 76 days. By no means do we have temperatures that are perfect for growth each day here in Iowa, but hopefully this shows some data that can help you determine if you can grow a crop.



Fifth: For those who have read the above information and feel that it is now hopeless for them to try to grow sweet potatoes, I offer the following challenge. You can “alter” your heat units in a cold climate. The only way I was able to grow much the three years I spent in the Panhandle of Northern Idaho, where nighttime temperatures got down to the 30’s most nights, was to trick or alter the environment. I used lodge pole pine saplings and made an A frame structure and covered it with plastic. I then enclosed both ends, only opening the ends on the hottest of days and faithfully closing the ends every night. There, the average daytime high was around 80 deg. F in the summer and around 40 deg. F at night, in other words about 5 heat units a day for most days. By using the A frame plastic enclosures, I could get it up to 95 deg. F in there in the daytime and keep it at around 55 deg. F at night without any supplemental heat source. Therefore, I could get 20 heat units a day instead of 5. I never had the courage to try sweet potatoes there, but by using this method I was successful with melons, tomatoes, and cucumbers that otherwise were either impossible or close to a miracle. You can speed it up even more with planting on black plastic, something I never had access to at that time . Living here in Iowa there are no lodge pole pines so a similar structure could be made out of stiff number 9 wire or, if you are talented, plastic electrical conduit.


https://www.sandhillpreservation.com...ng-information

Here is a chart I found interesting on stages of development of the sweet potato

https://keys.lucidcentral.org/keys/s...evelopment.htm