When it comes to plants, they all have the same basic needs: sun, food and water. When starting seeds indoors you have to create an optimum environment that provides all of these basic needs, and then some, to help make your seeds germinate into strong and healthy seedlings for your garden.
Though plants have different temperature needs, most seeds require an average soil temperature of about 75 degrees F to germinate. This means if you are starting your seeds in an unheated greenhouse, cold basement or other area that is not at a controlled temperature you will need to provide supplemental heat to ensure proper germination. There are some exceptions to this rule- seeds that require lower or warmer temperatures- so it is best to check out your seed packet for any important soil temperature info.
Once your seeds have germinated they will also need the correct temperatures to grow correctly. Cool weather crops, such as those in the brassica family, prefer cooler growing temps and will not grow as well in a sweltering hot house. Tomatoes, peppers and eggplant on the other hand will grow much more quickly once the air temperatures are warm. Still 65-70 degrees is still a nice temperature to keep your seedlings at to ensure that they don’t grow too fast and get long and leggy.
When I talked about the common seed starting problems, I mentioned that poor germination was often a result of incorrect planting depth. This is because if you plant the seed too deeply it will run out of energy before it reaches sunlight to make more. If you plant the seed to shallow, you run the risk of letting the seed dry out- and it will die before germinating. Some seeds, such as lettuce, actually require light to germinate, so you will need to simply press the seeds into your soil as opposed to covering them- the back of your seed packet will usually inform you if this is the case. A good rule of thumb is to plant the seed no deeper than it’s diameter.
Water is one of the most important part of starting seeds. Too much leads to disease, mold or fungus and too little will lead to….dead plants. When starting your seeds it is best us a spray bottle to lightly mist the soil to keep it evenly moist. You will have to water more often to prevent drying out, but you will lessen the risk of disease or rotting seeds. Keep in mind that starting your garden from seed is more time consuming- if you use small seed trays or peat pellets- you may have to spray your trays a couple of times a day to keep the soil moist. Once your seeds have germinated, you can begin to water more deeply, allowing the soil to dry in between waterings. You can even allow your seedlings to wilt just slightly before watering to help them toughen up and strengthen their roots.
Your seed starting soil is what gives your seeds the best start possible. Many people agree that a soilless mix is the best way to go. You can buy peat pellets, a premixed seed starting mix, or mix your own. Usually this mix would be equal parts of vermiculite, perlite, peat moss. I, however, usually mix mine with (approximately) 1/3 organic potting soil and 2/3 peat moss and have no problems. If you do some looking you will find that most people have their own versions of seed starting mediums- from soil straight from the garden to a mix of many ingredients. To get an idea of others’ mixes you can check out Better Hens and Gardens Mix or The Mind to Homestead’s simple mix. You can also check out this thread on my Facebook page where lots of others shared their seed starting mixes! Personally, I think if the seeds I plant straight outside in the garden can germinate in a rich, compost-filled, non-sterile medium- than my indoor seeds can too.
Most seeds do not require direct light to germinate, but once they sprout they will need about 14-16 hours of light per day. You can place your seed trays in a south-facing window, under artificial grow lights, or in a green/hoop house- provided they are at the right temperature. If you are using artificial lights make sure that their height is adjustable so that they can be moved up as the seedlings grow. You will want to place the lights as close to the plants without touching. If you are growing on a windowsill you may still need to provide some artificial light- especially if you are starting your seeds in the winter when the days are shorter. Don’t forget to turn your trays often so that all the plants have an equal chance at the light to prevent legginess!
Providing for these 5 basic needs, you should be well on your way to strong and healthy seedlings. Do you have any tips do you have for those new to starting seeds? If you are just starting out, what questions do you have about the process? Share them in the comments!