Potatoes won’t thrive if planted in summer

Question: I want to plant potatoes here in Las Vegas. Our season is timed different than others, though, so there aren’t seed potatoes available now for a mid- or late July planting. Will standard Yukon gold, Russett, fingerlings or sweet potatoes from the grocery survive here? Or can you suggest where to get some suitable seed potatoes?

Answer: You are planting too late if you put them in the ground in July. We need to plant Irish potatoes here in late February or early March. Purchase seed potatoes early in the spring. Sweet potatoes are a hot-weather crop and need to go in later when soil temperatures are warm, in late April or early May.

Any Irish potato can be quartered and used for seed. Potato seeds are not seeds at all but cut up potato tubers. When cutting potato tubers for seed, make sure each piece has at least two eyes, or dimples, and plenty of tuber connected to it.

Sterilize knives used for cutting and allow the cut pieces to “heal”€ in the refrigerator, moistened, for a few days before planting. Warm seed pieces taken from the refrigerator to room temperature before planting.

I have used potatoes from the grocery stores for seed, but you should know that they are not certified disease-free, so diseases are more of a potential problem. Purchase organic potatoes for seed as standard potatoes may be treated with a sprout inhibitor. Sprout inhibitors are sometimes applied to keep them from sprouting in storage.

All of the potatoes you mentioned will grow here, including sweet potatoes. Consider Red Pontiac and Red La Sota for red-skinned varieties as well as those you mention. Also try blue potatoes, such as Adirondack Blue as well as fingerlings.

If you’€™re going to grow potatoes here, make them special because regular old potatoes are not terribly expensive to purchase. I don’€™t know of a potato that will not grow here.

— Bob Morris is a horticulture expert living in Las Vegas and professor emeritus for the University of Nevada. Visit his blog at xtremehorticulture.blogspot.com.