How to start seeds indoors for your garden
Starting seeds indoors is a great way to get a jump start on your gardening season and have healthy, strong plants ready for transplanting into your outdoor garden.
This is the part 3 of the Starting a Garden Series. Read along to start your gardening journey with important practical information. At the end of the day, you will do gardening your way, but knowing some basics will set you up for success.
Also on this series:
1. Want to start gardening? Here’s how.
2. Soil health and why your plants aren’t growing
In the winter and spring months, starting seeds indoors allows you to grow warm weather crops in a controlled environment before outdoor temperatures are suitable for planting. Here is a step-by-step guide to starting seeds indoors during the winter and spring months.
My indoor seed-starting station.
Materials Needed
Seeds of your chosen plant variety. I recommend Botanical Interests and Johnny’s Seeds for organic good quality seeds.
High quality seed starting mix or potting soil
Containers for planting (such as seed trays, pots or recycled containers). I love these Epic 6-Cell Seed Starting Trays because they are sturdy and reusable. To use those, you will also need to get 1020 trays to keep all your little trays organized and water without making a mess. And to keep your seeds from drying while they sprout, specially in dry weather like here, consider also investing in some plastic domes for your Epic 6-cell trays. These are old sturdy and will last for many years.
A shelving unit to build your seed starting station
Grow lights: these can be attached to the shelving unit easily
A heat mat for seedlings that need warm soil to sprout like tomatoes and peppers
A spray bottle and watering can to keep your seedlings moist
Labels and a waterproof garden marker to keep your seedlings organized
Clippers to thin growing seedlings
Step 1: Choose Your Seeds
The first step in starting seeds indoors is to choose the seeds you want to grow. Consider factors such as the size of your indoor growing area, the amount of light available, and the type of plants that are best suited to your climate. Read the seed packet to make sure you choose seeds that are suitable for starting indoors and to know when to start them based on how long they take to grow and when is your last frost date – meaning when you are able to plant them outdoors safely.
Step 2: Prepare Containers
Prepare your soil by making sure it has enough water. If your soil is dry it might be hydrophobic, meaning it repels water. In this case you’ll have to mix or massage the soil with water to make sure it’s rehydrating and there are no dry spots. You want it wet enough to hold in your hands, but not soupy. Fill your seed-starting trays with this soil.
Step 3: Plant Seeds
Plant your seeds according to the package instructions, as different plants have different requirements for depth and spacing. Be sure to label each container with the name of the plant and the date it was planted for your records.
Seedlings growing under grow lights.
Step 4: Provide Light and Heat
Some seedlings need light (lettuce) and some need heat (tomatoes) to sprout. After sprouting they will all need light. If you have a warm, sunny location in your home, such as a south-facing windowsill, this can be a good place to start your seeds, but often this isn’t enough light and you will end up with leggy seedlings that won’t thrive. Ideally, you use grow lights to provide the necessary light for your seeds to grow strong. Ideally, keep the lights on for 14-16 hours a day and adjust the height of the lights as the seedlings grow to ensure they receive the appropriate amount of light.
When your seedlings have 2 or 3 sets of leaves it might be time to thin the ones where more than one plant is growing. This is because most plants benefit from having space between them. Peppers I find to be an exception and usually let 2 plants grow together as one.
I set up my seed-starting shelving unit where the top shelf is the closest to the light and the bottom one the furthest. This way I can start seeds at the top, close to the light, and move them down to the next shelf as they grow taller.
See how every shelf is slightly taller as you move down the unit.
Step 5: Watering
Water your seedlings regularly, making sure the soil stays moist but not waterlogged. Use a spray bottle to avoid disturbing the seeds and seedlings. As the seedlings grow, you may need to water more frequently to keep the soil moist. At this point, I like to water my trays by adding water to the 1020 trays with a watering can and letting each seedling absorb water from the bottom.
Little toddler helping to water seedlings.
Step 6: Monitor Growth and Transplant
Monitor the growth of your seedlings and make sure they have enough light, heat and water. Once they have grown their first true leaves, they are ready to be transplanted into larger pots or outside into your garden. Make sure to harden off your seedlings gradually by exposing them to outdoor conditions for longer periods of time each day for about a week before transplanting. This is important because indoor conditions are much milder without winds and harsh movements, as you harden them you give them a chance to strengthen and prepare for life outdoors with less shock.
Starting seeds indoors is a great way to get a head start on your gardening season and to enjoy growing your own plants. With a little bit of care and attention, your seeds will soon become healthy, strong seedlings ready for transplanting into your garden.
