However, there are a few things you need to be successful with indoor seed starting. None of these items are expensive, and many of them can be used year after year.
Equipment for Indoor Seed Starting
Lights: The best lights for your indoor seed starting set up are the shop lights that you can find in any home center or hardware store. These are the four-foot long lights that you hang from the ceiling or a shelf with chains. They are very inexpensive, and are a good choice because you can fit a couple of flats (or several individual pots) under each light. Even more importantly, you can adjust the height of your lights over the seedlings. This is important because your lights should always be two to three inches above the tops of your seedlings. This will ensure that they get enough light and you won't end up with thin, scraggly seedlings. The chains make it easy to keep adjusting your lights during the weeks that your plants live indoors.
Seed Starting Mix: The key in growing successful seedlings is the same as the key in growing successful garden plants, and that is good quality growing medium. In the case of seeds, you need to start with a sterile, soil-free mix. There are several good bagged products that are composed of sphagnum peat and perlite. You can also make your own mix, which is a good option if you are doing a lot of seed sowing. Do not use garden soil, and potting soil is not a good option either. Garden soil is far too heavy and contains pathogens that can result in poor health or death for your seedlings. Potting soil can also contain pathogens, but, depending on the brand, can also be too heavy or contain items like sticks and pebbles. Some even contain chemicals that inhibit germination. A sterile, soil-less mix is what you need.
Containers to Sow In: There is a huge variety of containers that you can choose from when you decide to start from seed. You can use plastic or pressed peat flats for starting a large number of seeds that you will prick out and transplant later. You can buy plastic cell packs, which many of us are familiar with. You can buy individual peat pots or peat pellets, which you put in the ground along with the plant. You can even use recycled materials from around the house, such as individual yogurt cups, egg cartons, or milk cartons. What you use will depend on both your budget and what types of seed you are working with. Each type of container has its strengths and weaknesses, and it seems that every gardener has their own favorite kind of container to start seed in.
Plastic Bags or Covered Trays: When you first plant your seeds, they will need a period of high humidity and even moisture to ensure germination. The best way to guarantee that the soil stays moist is to cover your flat or pot with clear plastic, creating a miniature greenhouse. You can buy kits at the home center or nursery that consist of a bottom tray and clear plastic dome for this purpose, and these are very convenient. You can also buy large zipper bags and place your pots or small flats inside, keeping the plastic away from the soil so it doesn't impede germination.
Misting Bottle and Watering Can or Shallow Tray for Bottom Watering: Watering is a tricky proposition when you first plant your seeds. If the flow of water is too heavy, your seeds will float away or end up in corners of your flats or pots instead of in the center. Your best options early on are to either mist each container well, or to set the entire container in a pan of water for bottom watering. Once your plants have developed roots, a standard watering can will work fine. One with a "rose" attachment is even better.
Plant Markers: You'll need to keep track of what you planted, and plastic or wooden plant markers or tags are the best option for this purpose.
Larger Containers for Transplants: If you are growing large plants like tomatoes, you may need to pot them up into larger containers before they're ready to plant out into the garden.
Fish Emulsion: Once your plants develop their first true set of leaves, they'll need to be fertilized. The soil-less mix you started the seeds in doesn't offer any nourishment to your plants. Once every two weeks, water your seedlings with fish emulsion, which has been diluted by ½ of its normal recommended dosage.
Seeds: The fresher the better, but if they are a year or two old just sow extras in case they don't all germinate.
Other Options: There are a few other items that can make your seed starting set up work easier or more effectively. Other items you might want to add are a timer for the lights (so you won't forget to turn them on or off), a fan to increase air flow and help prevent fungal diseases, and a heat mat for heat-loving seedlings like peppers and eggplants. With these inexpensive items, you can ensure that your plants will get off to a great start.