How to Grow Seedlings Indoors

The traditional way of gardening is growing plants outdoor in natural habitat. Technological advancement has introduced various gardening techniques. Outdoor gardening is common, however, these days indoor gardening is also very popular. There are various ways of growing plants indoors. One conventional method of indoor gardening is growing plants in the greenhouse. Another way of indoor gardening is tunnel gardening, in which plants are grown in plastic tunnels. Indoor gardening is also done in warehouses shades where microclimate is created for the plants. One less common indoor gardening is vertical gardening, where plants are grown indoors by placing them vertically on stacks inside a warehouse.

Getting started with seeding

No matter what kind of gardening you are doing, the first stage of gardening begins from sowing seeds. You can, of course, grow plants from a stem; however, not every plant will grow from stem.  When you sow seeds, they will grow into seedlings in 20-25 days. Some seedlings need repotting, and some seedlings do not require repotting.  Therefore, while sowing seeds, you need to take a couple of things into consideration. You need to check whether the seeds need repotting or not, whether the season is favorable for the plant or not, whether your geography is favorable for your plant or not etc.

You can sow your seeds outdoors as well as indoors. There are two purposes of indoor seed starting.

  1. Outdoor climate is too harsh for seedlings; it might be too cold or too warm. Outdoor environment also contain too many insects and pest that damage young plants.
  2. When you are growing seedlings indoor, you can grow the seeds in a controlled environment. You can grow any seeds no matter what season or climate it is.

Whether you are planting seedlings outdoor or growing plants indoor, you can start indoor seedlings. Indoor seeding is best for the plants that need warmth during the growing season. Indoor seedling is also a better option for growing seed if mildew is a problem in your area. Indoor seedling is also a better option during the hot season or dry season.

Things you need to know about growing seedlings indoors

However, before you start indoor seeding, you should always check the temperature and light requirement of the plants. Each plant has unique needs. Indoor seeding is good for the plants that grow in the warm climate as well as cold climate.

Starting seeds indoor is not a complicated process. However, you need to understand a couple of things such as:

  • Potting soil
  • Containers
  • Light
  • Temperature
  • Water
  • Feeding

Potting soil

You can either buy potting mix or make your own potting soil. Since we have already explained how to make potting soil, we will discuss basic things. Your potting soil should have enough nutrients for the seeds to grow. Your potting soil must be sterilized, and your potting soil should contain moisture.


You can grow seedlings in a seeding tray, plastic bags, tin cans, or a vase. While planting seeds 2-3 inches of soil will be enough for your seedlings to grow well. The seeds should not be buried too deep inside the soil. The level of soil that you cover the seedlings should be based on the size of seeds. The containers should always be sterilized and fill with a good potting mix. You should also have drainage so that water does not clog on the roots.


Some seeds grow in the dark and some seeds grow in the light. For the seeds that grow in the light, you should always place them in a place where it gets sunlight. If you cannot provide sunlight, you should give them artificial light. For the seeds that grow in the dark, you should cover them with a thin layer of peat moss.

When the seeds sprout, they need light. If you cannot provide natural light, use fluorescent or filament lamps. When the seedlings do not get enough light, they will become yellow and feeble.


When you sow the seeds, it passes through two stages: germination and growing.  Generally speaking, seeds need warmth while germinating. When the temperature is too cold, germination does not occur or occurs too late. How much warmth the seeds need depends on the variety of the seeds. You can increase the temperature by providing warmth through filament bulbs or other heating system, but never use gas heater.

What kind of temperature is required in growing stage depends on seed variety. In most cases, room temperature will be enough for the seedlings.


When you sow the seeds you need to water them thoroughly. However, you do not need to water as long as the soil is moist. Water the plants only when the soil cracks.


Prior to a week or two of sowing the seed, you should add fertilizer to your potting mix. The second feeding session should begin when the seedlings are at least one inch. In the growing stage, seedlings need more nutrients. However you should make sure that you do not use excess fertilizer. A good way to use fertilizer is by mixing it in water and then spraying it on the soil.

You should watch the seedlings daily. If the seedlings wither or become yellow, you should find the cause. It could be because you are giving too much water, the plants are not getting enough light or insects are damaging the roots, stem, or leaves.

Tips on indoor seedlings

  • You can grow your indoor seedlings on egg shells. When you crack the eggs, make sure to crack open only on the top. You can then fill it with potting soil and sow seeds.
  • Toilet paper rolls also make great seed planters.
  • You can use egg cartons or egg shells (with the top broken) to grow seeds.
  • Caffeine is a natural herbicide. Sprinkle tea and coffee grounds on the potting soil prior to sowing seeds.
  • Create a good drainage system for your seedlings. If there is excess water, the seedlings will die.
  • You can plant marigolds in your garden as insect deterrent.
  • Mildew can be a great problem while seedling indoors. Mix one part milk with nine parts water and spray it lightly on plants to control mildew.
  • Create a mixture of one tablespoon of liquid dishwashing soap and one cup of cooking oil. Put three tablespoons of this mixture in one liter of water and spray on plants. This will control pest on your seedlings.
  • A mulch of pine needles will control weed growth as well as retain the moisture in the soil.

4 thoughts on “How to Grow Seedlings Indoors

  1. Thank you admin for such an useful article. This indeed helped me to grow indoors seedlings very well.

  2. Thank you for this wonderful and useful post. I am a hobbyist gardener and I enjoyed reading all the articles published on the site.

  3. The most important thing to consider while growing seedlings indoor is providing light to the plants. Even though you can give artificial light to plants, it is very important to expose plants to sunlight.

  4. It is easier to grow seedling indoors compared to outdoors because you can easily protect your seedlings from harsh weather and pests. However, while growing seedling indoors, the most important thing to consider is provide required amount of light.

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