I bought Burpee Nasturtium Fordhook Favorites Mix Nasturtium seeds. Yesterday I planted a few, using the sowing instructions for depth and distance. I obviously hadn't looked closely enough at the package because today I noticed this message above the sowing instructions:

NOTE: To aid germination, rub seed with nail file.

I've planted these same seeds for a few years, and they've grown well, so I'm wondering about the importance of that advice. It makes sense that the seed might sprout more easily if the coating isn't too hard, so maybe that's the point. However, I'm afraid I might damage the seed by giving it a manicure!

If that is indeed important, how much rubbing is enough? Also, should I dig up those that I just planted or let them be?

A picture of the seeds still in the packet shows all different sizes and shapes. The textured outer shells are fairly hard, and the dark brown seeds look like they've fallen out of the shells. In the past, I've just planted whatever I've found in the packet and ended up with lots of healthy plants.

I have a feeling I'm overthinking this, but am just asking since I've never seen this before, and of course I want maximum germination success.

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  • This is an update for anyone who comes along. I planted some seeds without scarifying them, and some following @kevinsky's method. Some of the untreated seeds germinated, while all of the lightly sand-papered seeds did. While it wasn't a huge difference, it was worth the small amount of time and effort to prepare them. Also, in case you're considering this variety, it grew quickly in full sun, and more slowly in partial shade. The flowers were smaller than they look on the package, only about 3" across, but they were long lasting and tasted yummy. Commented Dec 22, 2016 at 1:03

1 Answer 1


This process is called scarification. It can be a pretty low tech operation as the suggestion of a nail file indicates. The purpose is to allow water to penetrate the hull of the seed and send the signal to grow.

I use a fine grade sandpaper 80 or even 120 grit.

  • Place on a hard surface with grit side up
  • place seeds on half the sheet
  • fold the sheet in half so the seeds are between two sides with grit
  • apply pressure and rotate
  • usually 20 to 30 seconds is good enough for small seeds
  • larger tougher seeds could need a minute
  • Great shortcut. Commented Jun 26, 2023 at 12:15

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