Pre-Soaking Microgreen Seed before Planting

Certain varieties of microgreen seed will sprout easier when the hard shell that surrounds the seed has been softened with moisture. There are some microgreen seeds that need a jump start to begin the sprouting process and soaking overnight in water is an easy solution.  Growing microgreens is easy and fun and taking this extra step can ensure a bountiful harvest.

While pre-soaking seeds is not mandatory, certain varieties of microgreen seed will sprout easier when the hard shell that surrounds the seed has been softened with moisture.  When seeds are pre-soaked, there is a quicker germination time and more even growth of stems and first leaves. Microgreen seed growing at the same rate will a produce thick and dense crop which will make harvesting much easier with just the snip of scissors.

How to Pre-soak Microgreen Seed

The pre-soaking process is not difficult. Measure out the amount of seed that coincides with the size of your growing container. I like to rinse the seeds first to wash off any residue and then drain out any excess water using a small strainer. For home use, those tiny strainers you can get at the dollar store work perfect for most seeds. Then I fill the bowl with water to about 1" or more above the seeds. Some larger seeds (such as wheat grass) may require extra water because they really absorb the moisture for the initial soaking.
 
Cover the bowl with a lid or paper towel and place in a warm area for about 12 hours or overnight. The seeds do not need any light during this sprouting phase, but I recommend you keep the bowl in sight while the seeds are soaking so you remember they will need your attention. Seeds left too long immersed in water can begin to spoil.

After about 12 hours, drain off the soaking water using a strainer. Wash off the seeds with the sink sprayer and then drain off any excess water. At this stage, you don't want the seeds to be dry, yet you don't want them standing in any water.

Leave enough moisture on the seeds to prevent them from drying out while waiting for the sprouts to pop out. Return seeds to the soaking bowl, cover bowl and let the moist seeds continue the sprouting process for about 12 to 24 hours more or until tiny sprouts burst out of the seed shell. Some seeds will absorb moisture very easily, so I check on the covered seeds about every 6 hours and rinse and drain as necessary to keep them moist but not soaking in water.

By pre-soaking microgreen seeds, you can monitor the sprouting process closely and be assured you are using viable seeds that will give you a successful microgreen harvest. Seeds that float to the top of the water are telling you that may not sprout. So the pre-soaking process can also serve as a seed test that can prevent you from wasting additional time and resources and keep the fun in growing microgreens.

After about 36 to 48 hours from the first wetting of the seeds, the seeds will have tiny sprouts popping out of one end of the seed shell. When the seeds get to this sprouting stage, transfer them to the growing medium, such as soil or a natural fiber pad. Pat seeds lightly into soil and let the exposed seeds continue with the sprouting process to the desired growth stage.

Sunflower seeds beginning to sprout

Tiny sprouts popping through the wheatgrass seed

After about 36 to 48 hours from the first wetting of the seeds, the seeds will have tiny sprouts popping out of one end of the seed shell. When the seeds get to this sprouting stage, transfer them to the growing medium, such as soil or a natural fiber pad. Pat seeds lightly into soil and let the exposed seeds continue with the sprouting process to the desired growth stage.

Recommended seeds that should be pre-soaked

Mucilaginous seeds that turn into a gel upon contact with moisture, such as basil, arugula, cress, mustard, chia and flax should not be pre-soaked. You will end up with a sticky gooey substance that is difficult to spread on the growing medium. Sprinkle these types of seeds directly unto the growing medium and then moisten with a spray mist.
 
Small microgreen seeds such as broccoli, cabbage, kohlrabi, radish, and kale can benefit from pre-soaking. If you are seeding a large area, such as a 10”x20” nursery flat, wet seeds can be difficult to spread across the large surface. In this case, sprinkle dry seeds onto soil and cover with a very light top coat of soil and then generously mist the topsoil. The topsoil covering will help retain the extra moisture these type of seeds need to break their outer shell.

Large seeds benefit from a pre-soaking process and are usually not difficult to spread across a larger surface. Chard, beet, sunflower, and pea seeds grown as shoots or microgreens are commonly pre-soaked.

Larger seeds such as wheatgrass, sunflower, beet, and peas will need extra moisture to break the outer seed shell.

If you enjoy a healthy smoothie or veggie juice, cereal grasses such as barley grass, wheatgrass, oat grass, and alfalfa are considered gluten-free in the microgreen phase, before the new seeds develop into the grain phase. These grass seeds will also benefit from pre-soaking.

To help ensure that even growth development will take place, pre-soaking seeds can jump-start the germination process. In a direct sow process, uneven watering or misting can result in dry patches in the growing medium, and when that happens, some seeds can be delayed in germinating and may be snuffed out. So the extra steps to wet and drain the seeds and let them germinate for a day or two is well worth the effort.

Enjoy your healthy microgreens.