Germinating Seeds Indoors & Caring for Seedlings
At first glance, a seed appears to be just a small, simple thing. But hidden inside is pure potential. Hidden within a seed is the potential to grow into a mature plant, which can host beautiful flowers and delicious fruits. A tiny seed can hold the key to some very big things. From the foods we eat to survive to the medicines we take to stay healthy, many find their humble beginnings as seeds. Inside that simple looking seed exists all of the genetic information needed for that plant to grow throughout its entire life cycle. Whether a certain plant is destined to create fruits, grains, or maybe just oxygen, its destiny is retained inside that little seed. Getting that little seed to germinate in doors can be tricky, but with some help from you, it will germinate quickly.
When germinating seeds at home or in a greenhouse, the first thing to think about is whether or not a certain seed should be started indoors, and transplanted to another location, or if it should be directly sown into the soil (or other growing medium) were it will find its permanent home. Plants, like radishes and carrots, should not be started indoors and then, transplanted outdoors at a later date. Doing so may result in disrupted growth, which can lead to unfavorable results. However, starting plants, like tomatoes, peppers, and cucumbers, indoors is a great way to get an early jump on the outdoor growing season or for an indoor garden. When choosing a medium in which to germinate the seeds, look for one that says something along the lines of, “seed starting mix.” This type of growing medium will likely have a moderate elemental fertilizer charge, which will surely benefit the newly sprouted seedlings. Seeds can be germinated in many different styles of trays and containers, so choose the type that best fits the project at hand. If starting just a few seeds, a simple, flat starting tray will work great. When planting many seeds at once, it may be wise to use trays that are divided into separate growing chambers. This will cut down on the amount of transplanting needed as the plants grow. Remember, most seeds will germinate at average room temperature, but some growers do use heat pads underneath the starting trays. Most seeds germinate at temperatures between 60-80 degrees Fahrenheit and the added warmth in the growing medium can speed up the germination process. However, for most seeds, it is not a necessity. Using supplemental lighting, like a T5 fluorescent bulb, can also help provide extra heat. Though seeds may not need light in order to germinate, the coming seedling will surely need light, so having a light source procured and ready is a good idea. I would advise against starting seeds in a bright window sill because the glass can alter the intensity of the sunlight and the plants may stretch and become ‘leggy.’
When preparing to germinate seeds indoors, I would suggest lightly moistening the growing medium before planting any seeds. This will help to ensure that the medium is not over saturated or water logged and that the moisture is spread evenly throughout. Using the eraser side of a pencil or the tip of the pinky finger, carefully make small divots in the medium at the desired planting depth. Many plants require a depth of around a ¼ inch. To find the correct planting depth for the type of seed being grown, consult the back of the seed package. I have found that the suggested planting depths on the package are very accurate and not following them can result in lower germination rates. If planting is occurring in a flat starting tray, space seeds at least an inch apart, either in rows or in a grid pattern. Gently place 1 or 2 seeds in each divot and cover lightly with growing medium (remember oxygen is important during germination, so don’t pack the medium down to much). Then, spray the entire tray lightly with a hand held mister. A pre-moistened soil should stay wet long enough for the seeds to germinate, but it may need to be sprayed with the mister occasionally to maintain even distribution of moisture. Some growers use starting trays that have plastic, hood-type lids. This will keep the humidity around the seeds at higher than average room levels and may help increase the chance of successful germination. Be sure to check the seeds nearly daily to maintain an optimal environment.
As the seedlings begin to pop up through the soil, there are a few environmental aspects that should be given proper attention right away: light intensity, humidity, and air flow. Remember the seeds of different plants will germinate in different lengths of time, so, once again, check the seed package for estimated germination times to know when to be ready. I mentioned before that many seeds can sprout in total darkness. With that said, once that plant breaches the soil, a sufficient light source is imperative. Those first “true leafs” will need a light source to perform photosynthesis and create carbohydrates, which will help sustain both normal plant growth and, most importantly, root growth. Without proper lighting, the early vegetative growth of a plant can be negatively affected and could cause long lasting problems that may result in a lower yield.
Humidity can be helpful during the initial germination process but, as the little seedlings begin to grow, high levels of humidity can spell disaster. As internal process burn up the seedlings energy sources, the plants will need to release oxygen as a gas through their stomata’s (a process called transpiration). As the oxygen leaves the plant, water and elemental nutrients are pulled up through the roots. In a humid environment, the stomata will remain closed and the roots will not take in water. If the growing medium is moist, as it most likely will be, the water will have nowhere to go and the roots will likely suffocate and die.
Air flow and humidity almost go hand in hand. A nice flow of air through the plants canopy will encourage the flow of carbon dioxide to the leaves and, subsequently, oxygen away from them. This is not just true for seedlings, but for plants in all stages of growth. A small fan on medium or low can help keep humidity levels low and the heat from any supplemental lighting to a minimum. Be sure to keep the rooting medium moist, but not too wet. Seedlings need water and going to long without can result in serious damage. However, if the medium remains too wet for too long it may impair root growth. As the seedlings grow, they will eventually exhaust any nutrient charge that the growing medium had to offer, so light fertilization with a nitrogen-based fertilizer may be needed while waiting to transplant into a different or permanent container.
So, as the seedlings grow, with proper care and attention, they inch closer and closer to fulfilling their own unique destiny. As we stand by, eagerly awaiting the literal fruits of our labor, it is important to remember that every plant we grow has entered into this life as a small, almost insignificant looking thing, that so many refer to as simply, just a seed.