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How to Start Seeds Indoors

Learning how to start seeds indoors means saving money when starting an indoor garden. Even for beginners, many fruits, vegetables, herbs, and flowers are straightforward to grow from seed.

To make sure that you set out in the right direction and meet with success as you start seeds indoors, you should:

  • Choose the right location for your indoor garden.
  • Select your seeds.
  • Choose the correct container.
  • Choose the right growing medium.
  • Know when to sow. 
  • Get the conditions right for germination. 
  • & Prick out and pot on your seedlings where necessary. 

This process remains the same whether you plan to transplant the young plants to your garden, or will grow the seedlings further indoors. 

How to Start Seeds Indoors

Where to Sow Seeds Indoors

Before you start sowing seeds indoors, you will need to give some thought to where this activity will be carried out, where seeds will be placed for germination to take place, and where seedlings will go once they sprout. 

Some seeds will need light for germination, and most seedlings will require sunlight to grow well. Some seedlings will need more light than others. Where enough natural light is not available, grow lights may be required. 

Sometimes, seeds can be sown on a sunny windowsill, in a location where temperatures do not fluctuate too wildly. Others will need temperatures to be higher, in which case a heated propagator or heat mat may be required. 

Choosing Seeds to Sow Indoors

Choosing seeds is an exciting part of having your own garden – whether this is outside or indoors. Not all plants for outdoor cultivation can be grown indoors – but many can. 

There are numerous edible and ornamental plants that you might choose to grow in an indoor garden. You can look far beyond traditional houseplants when growing indoors and, often, can grow far more food and other useful crops than you ever imagined. 

When choosing seeds, think about:

  • How much light they need. 
  • The temperatures and humidity they require.
  • How much care the plants will require (watering, feeding, etc…). 
  • The plants’ growth habits and how large they will grow. 
  • What the plants will provide to you when grown indoors. (Including tangible yields like food or other resources, or intangible things like beauty, or calm…). 

Containers for Starting Seeds

Once you understand which area will be used for an indoor garden, and have begun to narrow down which plants you want to start from seed, you can turn your attention to containers. 

You might choose to start seeds in the same containers in which they will continue to grow. But you might also start seeds in seed trays or other containers before transplanting the seedlings into bigger containers once they have grown a little. 

The great news is that you often won’t have to spend money to get great containers for your seedlings and larger plants. 

There are many reclaimed items and reclaimed materials that you might use for this purpose. Using reclaimed materials or pre-loved items in this way is a great step to take towards a more eco-friendly and sustainable way of life. 

Filling Containers for Seed Starting

Typically, seeds will be sown into a seed-starting growing medium, sometimes referred to as a seed-starting potting mix or potting soil. These pre-formulated mixes make it easy because they are created especially for starting seeds, with a light, airy texture that can improve rates of germination. 

However, you do not necessarily have to purchase a commercial brand because you can make potting mix using easily accessible natural ingredients including homemade compost, and leaf mold or composting wood chips, for example…

Some seeds can also be started on different media – on organic cotton wool or paper tissue, for example. You may remember experimenting with growing cress in eggshells at school in this way when you were a child…

When to Sow Seeds Indoors

One other key thing to think about before you start sowing seeds indoors is timing. Understanding when to sow seeds for the plants you wish to grow indoors is important. Seed packets will often provide the information that you need and there are also plenty of online resources. 

Many seeds, even when growing indoors, are sown in the spring. But there are seeds that you might sow inside your home all year round. Remember, timings may differ depending on whether you will grow inside year-round, or plan to transplant the plants to your garden at a later date. 

Troubleshooting Seed Germination

When sowing seeds, it is important to understand what is required for those seeds to germinate. Germination requires:

  • The right temperatures. 
  • Moisture. 
  • Oxygen. 

Some seeds also require light to germinate. These seeds should be sown on the surface of the growing medium or only lightly covered. 

To make sure you provide the right temperatures, check the requirements for the specific plant you are growing. 

Some seeds can germinate at a wide range of temperatures while others need temperatures to fall within a much smaller range. Use a heated propagator or heat mat where needed to generate the temperatures required. 

Before you fill your pots or seed trays, make sure that the growing medium you have chosen is moist but not saturated. Don’t water small seeds from above as they may get washed away. 

Overwatering or poor drainage can lead to waterlogging, which can mean seeds do not get the oxygen they need. Maintain the right moisture levels and use the right medium to avoid compaction and keep the mix aerated. 

Make sure you know how long germination is expected to take for the specific seeds you are sowing. Germination times can vary significantly – from just a few days to several months…

Pricking Out and Potting On

Once seedlings germinate, they will often need to be positioned in as bright a location as possible. They should be watered as needed but not excessively. 

Once large enough to handle, those sown into seed trays or communal containers will often be pricked out and potted into individual pots or other containers.