How to Start Seeds Inside with Plant and Aquarium Bulbs


Starting seeds indoors under lights is a good way to get a jump start on the spring growing season. Starting your garden or flowerbed from seeds can save money on expensive nursery-grown plants. Transplanting fully grown seedlings saves you the time it would take to sow the seeds outdoors and makes that time usable for plant growth resulting in flowers or food production. Different seeds have different germination times, so be sure to plan carefully so everything is ready by the time the last frost of the season is over in spring.

Germinating Seeds

Step 1

Fill the container, which can be a nursery seed tray, plastic or clay pots, with sterile seed-starting mix to three-quarters of the top of the rim. Use sterilized seed-starting soil from a garden store for fast and easy results. You can also make your own.

Step 2

Mist the soil so it is slightly damp but not wet.

Step 3

Use a plastic plant label or your finger to make a rows in the nursery tray or shallow depressions in the pots.

Step 4

Sprinkle the seeds evenly out in the rows for a two or three seeds per depression in the pots. Very fine seeds can be scattered if only one type is being planted per nursery tray. Be sure to label every pot or row with a plant label so you know what it is after it germinates.

Step 5

Cover the seeds with soil about two to four times as deep as the seed's diameter. Very small seeds do not need to be covered with soil. Most seeds from garden stores have sowing depth requirements written on the packet.

Step 6

Mist the covered seeds to get the new soil moist but not wet.

Step 7

Place the preformed plastic hood that came with the nursery tray over the top or use a piece of glass or plastic to hold in the moisture.

Step 8

Suspend the light fixture above the growing area according to the manufacturer's instructions. Make sure there is room above it so you can raise the fixture later as the plants grow.

Step 9

Install the plant or aquarium light tubes into the fixture. When using a standard 48-inch dual tube fixture, just about any type of bulb will work. But those in the daylight spectrum are the most efficient.

Step 10

Place the seedling tray or pots so they are 3 to 6 inches under the bulbs. When you see the first signs of germination, turn on the bulbs so that the plants get 14 to 16 hours of light a day. Move the lamps up when needed to maintain this distance.

Step 11

When the seeds germinate, remove the cover. Water only so the soil does not dry out completely but does not get soggy. They will be ready for transplanting into larger pots or for acclimating them for outdoors when they get their first true set of leaves.

Tips and Warnings

  • Don't use light tubes that are more than 1 1/2 to 2 years old. As fluorescent lights age, they loose their intensity.

Things You'll Need

  • Container (nursery tray or pots)
  • Sterile seedling mix
  • Misting water bottle
  • Plant labels
  • Seeds
  • Plastic or glass cover for containers
  • Fluorescent light fixture
  • Daylight spectrum tubes


  • Purdue University: Starting Seeds Indoors
  • University of Minnesota Extension: Starting Seeds Indoors

Who Can Help

  • Ohio State University Extension: Plant Propogation
Keywords: seed germination, winter seed starting, grow light

About this Author

Brian Albert has been in the publishing industry since 1999. He is an expert in horticulture, with a focus on aquatics and tropical plants like orchids. He has successfully run an aquatic plant business for the last five years. Albert's writing experience includes the Greater Portland Aquarium Society newsletter and politics coverage for a variety of online journals.