Once you have researched the timing and gathered your equipment, it's time to plant! Read on for step-by-step instructions for successful seed sowing.
Prepare your seed starting mix
It is essential to thoroughly moisten your seed starting mix before planting. Add as much water as the mix will comfortably hold. A good guide is to squeeze a handful of mix. If it sticks together in a clump, it is good to go. If water runs out between your fingers, it's too wet. In this case, either add some more dry mix or wait until some of the water has evaporated.
Fill the containers
Next, add the moistened seed starting mix to your pots or seed trays. Leave about a half-inch of room at the top. Press down gently to remove any air pockets.
Sow the seeds
Most seed packets will have instructions on how deep to plant the seeds. A good rule of thumb is to plant seeds at a depth of two times the width, or diameter, of the seed. For example, if you have a seed that's about 1/16 inch thick, it should be planted about 1/8 inch deep. Larger seeds like beans may need to be planted as deep as 1 inch. Poke a hole in the surface and add 2-3 seeds. This will ensure that you get at least one viable plant in each cell. Cover the seed with potting mix and gently pat down.
Be careful not to overdo the water or you will wash the seeds or the soil away. Typically, a watering can will be too forceful unless it is fitted with a fine sprinker head. A great option to use your kitchen sink faucet to gently sprinkle the top of the soil so it is damp, but not drenched. You can also add some warm water to the bottom of the tray. The water will wick up into the soil from below and keep the seed starting mix moist. Remember, seeds need moisture to wake from their dormant state, so it's important to make sure the mix is good and wet.
Label and cover
Be sure to label each tray so you know which seeds are growing in them. Trust me, you won't remember a week or two later and all seedlings look alike when they first emerge! Cover the flat with a dome or plastic wrap in order to maintain humidity and warmth.
If you have a heat mat, set the tray on top and plug it in. Heat mats are designed to only add the necessary warmth. You can leave them on 24 hours per day until the seedlings sprout. If you don't have a heat mat, place the tray in a warm area of your home, such as the top of the refrigerator, preferably to keep the tray at least 75 degrees.
Waiting is the hardest part! Most seeds will emerge within a week or two. Try to refrain from removing the dome too often to check on them or you may need to add additional water. Once about half of the seedlings have emerged, remove the cover and put them under the grow light.
Growing your own plants from seeds is an amazing experience! Keep in mind that some varieties of seeds have low germination rates or other requirements that make starting them more challenging. Each time you go through the process, you will learn and get better at it, so don't give up!
In my next blog, I will share some updates from my own seed seed-starting adventures this year and in upcoming posts, I will provide more information about how to care for your seedlings to prepare them for transplanting outdoors!