Humidity in Seed Germination

Sprouting seeds for hydroponics is the number one struggle people face when starting to use Hydroponicks’ DWC (deep water culture) systems. Most hydroponic systems online run into this issue as well, so we wanted to help everyone by explaining exactly why germination can be such a struggle when doing indoor gardening.

Germination is the process when a seed starts to grow into a plant. For seeds to sprout, they need the right conditions, and humidity is one of the most important factors. Humidity helps seeds absorb water, which triggers the growth process.

What is Germination

Seeds are like tiny sleeping plants. They stay in this dormant state until they get enough water to start growing. This first process of growing and going from zero to hero is called Germination.

The amazing thing about plants is that the seed starts with enough energy and nutrients to start growing without anything but some water and the will. Once a seed has sprouted, it moves on to establishing roots and moving into its seeding phase.

How Humidity Helps Plants Sprout

When a seed is exposed to moisture, it soaks up the water, waking up the plant inside. This process is called imbibition. Once the seed has absorbed enough water, it starts to grow roots and shoots, turning into a young plant.

Humidity plays a key role in this process. In high humidity, the air has a lot of moisture, which helps seeds absorb water easily and quickly. This consistent moisture is crucial because it allows the seed to continue growing without drying out. If the air is too dry, the seed can lose water too quickly, which can stop the germination process.

When you get seeds from the store, they are typically kept in a dry, paper envelope. This is to prevent them from receiving enough humidity or water to sprout before you are ready to start growing.

Once you are ready to plant them though, keeping them humid becomes extremely important.

Avoid Sunlight During Germination and Sprouting

Since seeds start with enough energy and nutrients to sprout and grow to seedlings on their own, it is actually best not to provide sunlight till they are seedlings. Plants love to battle for space and sunlight. Due to this, keeping a seed out of the sun stops other plants, bacteria, and algae from growing.

It took Cody at Hydroponicks a few attempts to learn this. He kept putting his growing seeds in the sunlight assuming they needed it. This stimulated algae to grow from the water he had from his sink, and this caused many, many plants to fail.

Lesson learned: Avoid sunlight until the plant has some roots and is strong enough to compete with the rest of the world of plants.

Best Humidity Levels for Germination

Most seeds need a relative humidity of around 60% to 70% to germinate well. Some plants, especially those from tropical areas, may need even higher humidity. 

However, it’s important to avoid too much moisture, as this can cause problems like waterlogging. Waterlogged seeds don’t get enough oxygen, which can prevent them from sprouting. Also, too much moisture can lead to mold growth, which can harm or kill the seed.

Most people recommend a spray bottle to mist the plants a few times to keep them wet but not soaked.

Simple Ways to Control Humidity for Seed Germination

Hydroponicks provides a Germination container to stimulate this initial growth. Technically any container that keeps moisture in, warm conditions, and avoids the sun will cause germination to happen, so anything with a cover will do.

We even started some of our systems by putting plastic wrap over them to keep moisture in. Eventually we moved onto the container we use today with a clear plastic lid. The cover traps moisture, keeping the air around the seeds humid.

This method creates a mini greenhouse just for sprouting our plants.

For those using hydroponics or other advanced gardening systems, controlling humidity is even easier. These systems let you set the perfect environment for your seeds, making sure they get exactly what they need to sprout.

Get Plants Going with Humidity

Humidity is vital for seed germination. It helps seeds absorb the water they need to start growing into healthy plants. By understanding and controlling humidity, you can improve your chances of successful germination, whether you’re a beginner or an experienced gardener. If you’re interested in learning more about how to create the best environment for your plants, especially in hydroponics, check out hydroponicks.co for more tips and information.