When to plant tubers in zone 5a?

[kwhitney992000]

When do potato tubers go into the soil? The last frost free day or can you do it before? 

[philagardener]

Sprout your tubers first in light (the British term for this is chitting; I lay mine out in trays) so the buds form and actively start growing before you put them in the ground.

I don't think a late frost will harm them as long as the sprouts haven't emerged above ground.  Planting in raised beds or containers can improve drainage and help warm the soil.  I think overly wet conditions are more of a concern when starting early.

After noticing for years that I was getting volunteers the next season, I tried planting some last Fall just to see what happens!

[paquebot]

In Zone 5a, can be done now. Despite what is normally cold right now, many plant on St. Patrick's Day if the ground can be worked. Main thing is to plant them at least 4" below grade and immediately hill another 4". That's plenty deep to protect them from any late frosts. Takes a long time for the plants to emerge and by then they are usually safe from frosts. If they are up and frost is forecast, merely hoe some soil over them for protection. I'm on the line between 4b and 5a and already have Pinto Gold in the ground.

Martin

[ferdzy]

My traditional rule of thumb is they get planted when the dandelions open. That means the soil is the right temperature.

But in fact, the last couple of years we have planted many of them in the fall, left them to overwinter, then they start to grow at the usual time. They don't always all survive the winter though. On the other hand, you can overplant them with spinach to overwinter as well, then pull the last of the spinach plants just as the potatoes are starting to sprout.

[paquebot]

Another point is what you want them for. If they are an early variety, you may want to start eating them in late-June. Those should be in the ground as early as absolutely possible. If they are a late variety for long storage, Memorial Day is perfect.

Martin