HOW TO START SEEDS INDOORS

Starting garden seeds indoors offers several advantages over direct sowing in the garden. First, it allows you to extend your growing season by starting seeds several weeks or even months before the last frost date in your area. This means you can enjoy a longer harvest period and potentially grow plants that require a longer growing season.

Second, starting seeds indoors gives you more control over the growing conditions. You can create an ideal environment for your seeds, including providing the right amount of light, temperature, and humidity. This control helps ensure better germination rates and stronger seedlings.

Last, starting seeds indoors allows you to save money. Buying seedlings from nurseries can be expensive, especially if you have a large garden. By starting your own seeds, you can grow a wide variety of plants at a fraction of the cost.

*BONUS reason _ I like to start planning early in the cold, late winter months, because the dreaming of spring, and starting my garden seedlings will bring that warm, lovely feeling just a little bit closer to reality!

When to Start Garden Seeds Indoors

The optimal time to start garden seeds indoors varies depending on the type of plant and your location. Generally, it is recommended to start seeds 6-8 weeks before the last frost date in your area. This allows the seedlings enough time to grow and develop before they are transplanted outdoors.

Cool-season crops like lettuce, broccoli, and kale can be started indoors as early as 8-10 weeks before the last frost date. These plants can tolerate cooler temperatures and can be hardened off and transplanted outdoors earlier in the season. 

Warm-season crops like tomatoes, peppers, and eggplants are more sensitive to cold temperatures and should be started indoors 6-8 weeks before the last frost date. Starting these seeds too early can result in leggy, weak seedlings.

To determine the last frost date in your area, you can check online, the garden growing climate zone map.    

Once you know the last frost date for your area, you can count backward to determine the appropriate time to start your seeds indoors. You don't want to start too early, and then have leggy seedlings and too cold of weather to transplant! I use the frost date as a guide, but usually start a week later. Some crops you can seed start continually all throughout the spring for concessive planting. I will do that for certain lettuces and peas.

Choosing the Right Equipment for Starting Garden Seeds Indoors

To start garden seeds indoors, you'll need a few essential pieces of equipment.

 Here's a list of what you'll need:

• Seed Starting Trays or Containers:  These are shallow trays or containers with individual cells or compartments to hold the seeds and growing medium. They come in various sizes and materials, such as plastic or biodegradable peat pots.  If you don’t have the funds to purchase these, that's OK! There are plenty of other options. I personally have used everything from plastic drink cups, yogurt cups, paper coffee cups, plastic domed produce containers, to handmade biodegradable newspaper cups. Use whatever you have!
  

• Seed Starting Mix: 
  

A lightweight, sterile growing medium is essential for successful seed starting. Avoid using garden soil, as it can contain weed seeds and diseases. Seed starting mixes are usually a blend of peat moss, vermiculite, pearlite, and a seed starter fertilizer. I like to mix my own and then add in each cup/cell, a little seed starting fertilizer.

When purchasing premixed soil, I use this brand of seed starter mix.

• Labels:
  

It's important to label your seed trays or containers to keep track of the plant varieties. Use waterproof labels or write directly on the containers with a permanent marker. One year I ran short on tags so I used white plastic knives purchased at the dollar store, and they worked perfectly fine.

• Dome or Plastic Wrap:  A transparent dome or plastic wrap can create a mini greenhouse effect, helping to retain moisture and create a humid environment for the seeds to germinate. I use a clear shower curtain, ripped lengthwise, purchased from the dollar store.
  

• Heat Mat:  Some seeds require warmer temperatures to germinate. A heat mat placed under the seed trays can provide the necessary warmth. Just remember that once the seed pops up, and you see green you need to remove the heat and turn on the grow lights! I use this type of waterproof heat mat.
  

• Grow Lights:   Proper lighting is crucial for healthy seedling growth. If you don't have access to sufficient natural light, you'll need to invest in fluorescent or LED grow lights. These are what I use in the winter, or colder months. Make sure you have 6500 kelvin lights for adequate lighting. For warmer months, I use the red and blue lights. that are cooler and less stress inducing for the plants.
  

• Mister or Spray Bottle:  A mister or spray bottle filled with water can be used to gently water the seedlings without disturbing the delicate roots. Once roots are a bit established, I like to water by placing starter cups with drain holes submerged in a tray of shallow water. By watering from bottom upwards, it keeps the top soil from growing algae or mold.
  

• Air Flow!  Don’t forget airflow! A small, battery operated or solar fan moves the air so there is less chance for mold and fungus growth. An added benefit is your seedlings grow strong roots from being conditioned in the breezy air.

Seed Starting Mix 

Fill the containers with the seed starting mix, leaving a small space at the top for watering. It’s important to start with a very light, fluffy medium so the baby root system can take hold and grow. Add a very small amount of starter fertilizer to the lower portion of the pot. Do not add fertilizer to the top! It will certainly grow fungus and mold. 

Next, moisten the mix before sowing the seeds to ensure good seed-to-soil contact and even moisture distribution. 

Light Sources for Indoor Seed Starting

Proper lighting is crucial for healthy seedling growth. Most seedlings require 12-16 hours of bright light per day to develop into strong plants. If you don't have access to sufficient natural light, you'll need to invest in artificial grow lights.

Fluorescent lights, especially T5 or T8 tubes, are a popular choice for indoor seed starting. They are energy-efficient, emit low heat, and provide the right spectrum of light for plant growth. Position the lights 2-4 inches above the seedlings and raise them as the plants grow. 

LED grow lights are another option, and they offer several advantages over fluorescent lights. LEDs are more energy-efficient, emit less heat, and can be fine-tuned to provide specific light wavelengths that promote plant growth. They are also long-lasting, reducing the need for frequent bulb replacements.

I have used both full spectrum white lights in the winter and early spring, and also the

red and blue light in the summer when the seedlings are growing in warmer weather. White light creates heat in the plant and can be stressful in the warmer months, so the blue and red light bars are best used in warmer months.

Whichever light source you choose, make sure to keep them on for 12-16 hours per day and adjust the height as the plants grow. This will help prevent leggy seedlings and promote strong, compact growth.

Temperature and Humidity Control for Indoor Seed Starting

Maintaining the right temperature and humidity levels is crucial for successful seed germination and seedling growth. Most seeds require a consistent temperature range of 65-75°F (18-24°C) for optimal germination.

To provide consistent warmth, you can place a heat mat under the seed trays or containers. This helps create a stable and warm environment for the seeds to germinate. Be sure to monitor the temperature regularly to prevent overheating, as excessive heat can harm the seeds or cause leggy seedlings.

Humidity is another important factor to consider. While the seeds are germinating, it's beneficial to cover the trays or containers with a transparent dome or plastic wrap to create a humid environment. This helps retain moisture and encourages faster germination.

Once the seeds have germinated and the seedlings start to grow, you can turn off the heat mats, remove the dome or plastic wrap, and turn on the grow lights!

This is literally my favorite part of seed starting! 

Make sure at this point to  have a small fan to keep a nice gentle breeze. This not only helps prevent mold, and damping off, but also helps the roots to grow strong.

Watering and Fertilizing Indoor Seedlings

Proper watering is essential to ensure healthy seedling growth. When watering, it's important to keep the soil evenly moist but not waterlogged. Overwatering can lead to root rot and other fungal diseases.

To water your seedlings, at first use a mister or spray bottle to gently moisten the soil surface. Avoid pouring water directly onto the seedlings to prevent damage. Water whenever the top inch of soil feels dry, and remember that smaller containers may require more frequent watering, 

Once the seedlings have developed you can start watering by placing them in a shallow tray filled with about an inch of water.  This method keeps mold, fungus and leaf blight to a minimum. 

As soon as you see their first set of true leaves, you can start fertilizing them directly. Use a diluted balanced liquid fertilizer, following the manufacturer's instructions. Start with a weak solution and gradually increase the strength as the seedlings grow.

Fertilize the seedlings once every two weeks, depending on their growth rate. Be careful not to over-fertilize, as this can lead to nutrient burn or stunted growth. Always monitor the seedlings' growth and adjust the fertilization schedule accordingly.

Transplanting Seedlings Outdoors

When your seedlings have grown and the weather has warmed up, it's time to transplant them into the garden. Before moving them outside permanently, it's important to harden off the seedlings gradually.

Hardening off involves exposing the seedlings to outdoor conditions gradually. Start by placing them in a sheltered location outdoors for a few hours a day, gradually increasing the exposure over the course of a week or two. This helps the seedlings adjust to the outdoor elements, such as sunlight, wind, and temperature fluctuations.  It’s helpful to have all the cups in a tray so you only have to transfer trays of plants versus individual little cups. 

Also, make sure to have up, and off of the ground. You don't want slugs or critters to start munching on all your hard work! I use a portable mini greenhouse rack for this purpose.

Another hardening off method that I started implementing is to look in the upcoming forecast for a consecutive row of overcast days. You will want to place your mature seedlings out ALL DAY for a consecutive 3-4 overcast days. Make sure to bring them back inside at night! By the end of day 3 or 4 they will be ready to transplant. 

When your plants have been hardened off and are ready to transplant, choose a cloudy day or late afternoon to minimize stress on the seedlings. Dig a hole slightly larger than the root ball of each seedling and gently place them in the hole. Fill the hole with soil, firm it gently, and water well.

After transplanting, monitor the seedlings closely and provide them with adequate water until they become established. Protect them from extreme weather conditions, such as strong winds or heavy rain, until they are fully acclimated.

Starting garden seeds indoors is a rewarding and cost-effective way to kickstart your

gardening season. By following the recommended timeline, choosing the right equipment, providing adequate lighting, temperature, and humidity control, and practicing proper watering and fertilizing techniques, you'll be well on your way to growing healthy and robust seedlings.

With a little patience (the hard part!) and care, you'll be able to enjoy an extended growing season, have more control over your garden, and ultimately reap the rewards of a bountiful harvest. Happy seed starting!

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