Nicking Nasturtium Seeds

Some of you have been following along with my abysmal nasturtium germination rates this winter. My first sowing of probably 40 seeds yielded TWO, yes two, plants. I overnight soaked the seeds, then drained them and put them in soil later the second day. I kept the soil moist and it took about a week for the first — and only — seeds to germinate.

Ugh.

It was enough for me to question if I actually know anything about anything at all.

The seed coat on nasturtium seeds is solid. And that seed coat needs to soften to allow moisture inside to the seed so it knows it’s time to grow.

In previous years I’ve usually either sanded (nicked) the seeds or soaked them. I may have even sometimes done both.

Because I really want lush pink nasturtium tufts in the garden this summer, I ordered more cherry jubilee nasturtium from Renee’s Seeds about 2 weeks ago and started over. This time I wanted to be more methodical to see if I there was a different way to help these seeds successfully germinate.

Now, for perspective, in years past my nasturtium seedlings have thrived (see my April calendar). So finding myself in this humbling situation is perhaps compounded by the seed quality of this new source. Or possibly the Coco Loco soil I’m now using. I don’t feel like I’ve changed that much.

So about a week and a half ago, I decided to return to the concept of nicking, something I’ve tried but have been inconsistent about applying it to seed starting.

Nasturtium seeds are the only seeds I nick, by the way.

Nicking simply exposes a small area of the seed directly to the moisture in your soil. The results continue to blow me away. I have nearly 100% germination on these. And my soaked seeds have 2 plants across 6 pots (15 seeds) that have sprouted, and one started to emerge and has stalled.

Noteworthy is that my 2023 nasturtium are nowhere near where my 2022 nasturtium seedlings were. This is the great unknown of how our gardens will unfold. It will all catch up come summer.

I planted the seeds into 4” pots instead of 2” soil blocks or my 72 plug tray. In the past, both of those were viable options for germination, so I’m not convinced that was my issue.

I am keeping the soil a bit drier this time around; it is the same soil medium, so that variable should not be impacting me.

But seeing how much faster and better they germinate with this little extra step, I will definitely keep doing this for many years.

This will work for seeds you want to direct sow, too. Just give them a little sand in one spot and drop them into your garden.