It’s a good time to plant your TPS! here is some guidance shared last year.
Start seeds between March 1st and May 1 (they are slow as seedlings, so the earlier, the better). They need four to eight weeks (based on your preferences, needs, greenhouse space…) to grow before transplanting them outside. Plant 2 or more times as many seeds as you want seedlings for, and cover them slightly with soil (less than ¼ inch).
Read growing reports and questions from 2024.
Anybody direct seeding share your experiences! But I recommend doing that after you have some experience growing TPS.
Planting Instructions: When choosing or making your starting soil, be sure to include native field soil in the mix, but as weed free as possible (forest soil). Potatoes are healthier when they build relationships with soil microbes from the first moment of germination. Check out Going to Seeds’ free online course ‘How Microbes Help Plants Adapt” to learn more about this. Sterile soil is not at all ideal– in fact, the more microbes, the better. Keep nitrogen levels low– seedlings will be less prone to disease and legginess when they don’t have excess nitrogen, and lower fertility will encourage them to build mycorrhizal relationships early.
Depth recommendations vary-- but I’ve had better luck with healthy seedlings when sprinkling up to a 1/4 inch of soil over seeds.
Germination is best under cool, damp, and dark conditions. I put them on a shelf inside for the first few days (watch closely for germination and put in bright light at the first signs). Germination is best at 60-70 degrees, cooler than other nightshades. Germination may be slow– up to two weeks. After one week, be sure to put them in a bright spot with at least 8 hours of sunlight. As long as you have enough sunlight, grow lights aren’t needed. As they grow, give them plenty of outside time in the wind and sun to build vigrouous seedlings with strong stems.
Be prepared for uneven and spotty germination, tiny seedlings, and slow growth. Unlike other crops, potatoes have not been selected to have strong seedling growth.
This is what your seedlings may look like after a month, even if you planted multiple seeds per cell. Don’t worry about small or yellow seedlings, don’t choose them for planting.
). I am personally unwilling to work as hard as I do without a very solid percentage of a decent outcome. Hence, my breeding of the plants I do grow out this way are very much tilted to short-season; cold-hardiness; very-low water external water input; and flavor. The genetics will carry that trait as an innate expressioned baseline.
