TPS Skill Levels
By popular demand, but with some reluctance, I have introduced skill levels for TPS, classifying them as appropriate for beginner, intermediate, or advanced levels. The problem with this kind of generalized classification is that it does not really take climate into account. Low dormancy diploids will be intermediate or advanced in much of the continental USA, for example, but might be suitable for beginners in highland Hawaii or the southern Oregon banana belt. So, you need to take your conditions into account, but these categories will serve as reasonably conservative guidance.
These varieties or mixes are primarily tetraploids with good dormancy. They will produce many potential keepers with good yield and, with proper care, can be evaluated in the first year, making them suitable for small growing areas and less than ideal storage conditions. Very few will have high glycoalkaloids and those that do will rarely be very high.
These varieties or mixes have a lower fraction of keepers and they will be harder to evaluate in the first year, meaning that you will need to grow more plants and keep more into the following year than you would with beginner varieties. Intermediate varieties are good for people who have built up a little experience with beginner varieties and have worked out how they can store and evaluate more tubers. Some will have low dormancy, requiring specialized storage (refrigerated or under lights) if you want to keep them. Some will be short day tuberizers and will need to be grown well into the fall to produce anything. With often more diverse backgrounds, there is a higher chance of varieties with high glycoalkaloids.
These varieties typically produce a small number of keepers, are difficult to evaluate in the first year, may have wild type traits like long stolons or high glycoalkaloids, may have no dormancy at all, and may be short day tuberizers. They can be quite valuable, but they are only likely to reach their potential when grown by someone who has had several years of good results with easier varieties. The biggest risks are that you won’t get them in the ground soon enough or keep them growing long enough to get tubers and that you won’t recognize what has promise in whatever you do harvest the first year.