Soaking your seeds before you plant them is a way to end their dormant period quickly and insure more successful, and more even, germination. Some seeds--for example peas, lupine and spinach--all have very tough shells that water does not penetrate easily. This can lengthen the amount of time the seeds take to germinate and even prevent them from germinating at all. Soaking the seeds ahead of time swells and softens their shells and helps the plants come to life.
Read your seed packets and carefully follow any soaking or pre-treating instructions for seeds. Some seeds, like radish or lettuce, probably do not need to be soaked at all and can be sown directly into the soil.
Plan to sow your seeds right after soaking. Once you’ve broken their dormant period, the seeds have to start growing right away. Try to avoid soaking seeds right before a frost or any personal obligations that will prevent you from planting them.
Pre-treat very hard seeds, like lupine and morning glory, before soaking them. These seeds’ hard shells need a little extra help absorbing water. Rub the seeds gently between two pieces of very fine sandpaper to make fine scratches all over their hulls.
Place seeds into a clear glass jar. Fill the jar with the hottest water you can get from your tap. Make sure all the seeds are covered and that there is enough water for the seeds to absorb it and still stay covered in water.
Stir the seeds around so that they’re all in contact with water. Most seeds that benefit from soaking need to stay in the water for about 24 hours. Let the water cool off and don’t replace it with hot water. Once the shells begin to soften, hot water can harm the seeds.
Check on the seeds after six or eight hours to see if they are starting to swell. If any seeds are very swollen, take them out and plant them. If the seeds haven’t taken on any water, take them out and rub them gently with fine sandpaper. Replace them in the water.
Avoid over-soaking seeds. If any seeds start to sprout, remove all of the seeds from the water and plant them right away.
Pour the seeds out onto a few paper towels when they’re ready to plant. This will dry them enough to make them easier to handle, but the wet towels will keep the seed shells moist.