I’ve decided to start at the beginning, with sowing the seeds. Nasturtiums have a hard seed coat, and some sources recommend “scarification” to improve germination. Scarification means softening or removing part of the seed coat. I tried five different methods, and had one control group (i.e. no scarification). The purpose of softening or removing part of the seed coat is to allow water into the seed and thus get the germination process started more quickly and with more consistent results.
Unfortunately I didn’t have the foresight to start my little experiment early enough so that I could report on my findings today. But I should have some germination data to report later this week, so look for it in the Grab Bag post on Friday.
Soaking in Hot Water for 24 Hours
For the first group, I boiled water in my teapot and poured it into a cup. I then placed four seeds in the cup of boiling water and set the timer for 24 hours. Pretty easy!
Soaking in Hot Water for 3 Hours
This was a variation on the first method. Boiling water went into the cup along with the seeds, timer set for 3 hours, and away we went.
Soaking in Cold Water for 24 Hours
The third group had an even easier procedure than the first. I simply poured tap water into a cup, dropped the seeds in, and set the timer.
Filing the Seed Coat
Unless this method proves to be more effective than the others, I wouldn’t recommend it. I used a metal file to sand off a small portion of the seed coat. It was difficult to hold the seed firmly while filing it, and it was also hard to tell how much filing was enough without over doing it.
Chipping/Cutting the Seed Coat
For the seeds in this group, I used a nail clippers to chip a small part of the seed coat. It was easy, and quick. Next to no scarification, this would be my preferred method, because you can accomplish it quickly. I’m an instant gratification kind of gal.
This group of seeds was not scarified. With any luck, this group will germinate at the same time as the others, or even before them. In which case, I’ll be able to recommend that no scarification is needed and that nasturtium seeds can be sown just as you would other seeds.