Certain seeds with a hard seed coat take a bit more patience and work to grow successfully. Here we hope to give you a few pointers that can help you get some of those challenging seeds to sprout.
Here is a partial list. The first five belong to the Parsley family (Apiaceae). I am sure others will suggest more and we will keep this list updated.
- Celery & Celeriac
- Swiss chard (don’t need to soak overnight, just 1-2 hrs)
- Peas (can also be soaked in an inoculant)
Start by soaking seeds in warm water (90-100F or 32-38C). I like to start with a small cup and fill it halfway up. 2-3 hrs. later, add some more warm water. Soak overnight.
Some people put seeds on wet paper towels and wait until visible signs of sprouting and then plant the paper towel with the seed in the soil. If you wish, you can cut the paper towel into strips and line it with seeds. Keep the paper towel water wet.
For both approaches, use warm water when you plant the seeds. You can use water from a garden hose that has been out in the sun. Always put your hand in front of the stream and test before watering. If it is really hot and sunny this may be too hot, so use caution and common sense.
There are other methods like “mechanical scarification” — nicking, sanding, and filing the seed coat, but I’ve had success with the warm water approach. We’d love to hear which hard seeds you’ve started and your technique to get them to sprout!