How To Start Seeds Indoors Without Grow Lights | Veggies, Flowers, Herbs!

Welcome! This article contains affiliate links, meaning I get a commission if you decide to make a purchase through my links, at no extra cost to you.

Grow lights are perfect for germinating and growing seedlings indoors. But fancy LED light systems can be expensive. And, not all homesteaders have the space or budget for grandiloquent indoor growing lights. Luckily, there are alternative methods to start seeds indoors without artificial lights. We have a ton of experience doing this when growing herbsveggies, flowers, and fruits. We can show you how.

Growing many green seedlings inside near the windowsill.

We’ll also share some of our best indoor seed germination tips.

(Plus, our best tips for seed germination in low-light and suboptimal conditions.)

Sound good?

Then let’s begin!

Benefits Of Starting Seeds Indoors Without Grow Lights

Starting seeds indoors without grow lights has several nuanced benefits. Considering the low price of seed packets and seed-starting trays, germinating seeds without grow lights is arguably the most efficient way to start gardening. You never need to fuss with fancy setup or hardware installation.

Another benefit of starting seeds without grow lights is reduced energy consumption. Grow lights can use way too much electricity, especially if left on for long hours. We don’t have to tell you that energy costs keep skyrocketing. By skipping grow lights, you can save on energy bills.

Starting seeds indoors is also a garden-saving boon for gardeners with short growing seasons. Germinating veggie seeds indoors lets you extend your growing season by a few weeks or more. That might not seem like much if you live in a warm USDA growing zone, but for Northerners and New Englanders, a four-week headstart is the best way to ensure an abundant harvest rather than an empty garden!

Starting seeds indoors without grow lights is also incredibly easy to set up. You only need some healthy seeds, a sunny spot, a seed-starting mix, and seed trays with drainage holes.

Related – How To Grow A Mango Tree From Seed In 6 Easy Steps. Indoors Or Outdoors!

Our Super-Simple Seed Starting Process With No Growing Lights Required

Sowing plump pumpkin seeds into biodegradable peat pots.

Here is our tried-and-true 7-step process for starting seeds indoors without LED lights. Before we start – gather your supplies. You’ll need healthy seeds, soil starting mix, growing cups (or trays), and a bright, sunny window. (A heating pad and plastic dome also help. But are not necessary!)

Step 1. Choosing The Healthiest Seeds

Growing seeds indoors without grow lights is far easier if we have good seeds. So, don’t skip this part! We’ll need healthy seeds that are fresh, firm, plump, and crack-free. Aim for seeds well within their expiration date, sourced from reliable (hopefully local) suppliers.

Step 2. Fill Growing Cups With Seed Starting Mix

Fill your growing pots with nutrient-rich potting soil or seed-starting soil. The best potting soils usually have a coco coir, compost, sphagnum peat moss, tree bark, or vermicompost mixture.

You can use nearly any pot that you want for seed germination. Peat-growing cups work excellently in most cases. They make transplanting your germinated seedlings and plants in your garden a piece of cake since they’re biodegradable. They’re also small enough to fit tidily on your sunny countertop or windowsill.

Step 3. Sow Your Seeds In The Soil

The biggest trick to sowing your seeds is soil depth. Some seeds love germinating close to the soil’s surface. Others can sprout burrowed an inch or more in the soil. 

Sow tiny seeds like tomato, carrot, or lettuce about one-quarter of an inch into the soil. You can also gently press these seeds below the soil’s surface.

Plant larger seeds, like bean, sunflower, pumpkin, pea, or zucchini seeds, deeper below the soil surface, about one inch deep.

Step 4. Water And Cover Your Seedlings 

Germinating seeds with plastic wrap to create a microclimate.

Add a splash of warm water to your seedlings. We want our soil to remain consistently moist during the indoor germination process. But we don’t want the soil drenched. So, monitor the soil daily. Whenever it feels dry, add a splash of warm water.

Many seeds also react well to a plastic dome. You can use a clear plastic cup. A clear plastic cup helps lock in moisture and warmth. You can also use the bottom half of a sliced-in-half two-liter bottle.

(You can also use a plastic wrap to help create a warm and humid microclimate. Just like in the photo above.)

Step 5. Put Your Seeds In A Warm, Sun-Lit Room

Many veggie, herb, and flower seeds will germinate and flourish at 70 to 80 degrees Fahrenheit. But some seeds, like kale and broccoli, prefer slightly cooler temperatures. Follow the instructions on the seed packet!

Usually, placing the seeds in a warm, bright room works perfectly. You can toss your seed tray or cups near a south-facing window if you want the most sunlight possible. East and west-facing windows can also work for seed germination, but south-facing is usually better.

If your home is chilly indoors, heat mats can work wonders to boost your seed’s temperatures.

Step 6. Wait For Seed Germination

Growing tomato seedlings in seed trays on a bright windowsill.

Most viable seeds will germinate within one to two weeks. While you wait, observe your seeds. Water the seedlings as needed. Monitor the soil and ensure it doesn’t get too dry. Also, double-check the temperature. Don’t let the temperature dip below 70 degrees Fahrenheit.

Step 7. Transplant Your Baby Seedlings

Once your seeds have germinated, it’s time to pamper the baby seedlings. We want our baby plants to develop their first leaves and grow a few inches tall before transplanting them outdoors or into a bigger pot. Maintain a cozy temperature and keep the soil moist during this time.

Once your baby seedlings are of size, you can transplant them outdoors as long as there’s no risk of overnight frost. If you use peat grow cups, this step is easy! These cups are biodegradable, so you can sow the cup directly in your garden without disturbing the roots.

The above seed germination process works perfectly with many seeds, including the following. Try sunflowers, basil, mintcucumberzucchini, watermelon, butternut squash, Swiss chard, okra, eggplant, radishes, sweet melons, peppers, tomatoes, kale, broccoli, pumpkin, lettuce, yellow squash, or cabbage.

Related – How To Grow An Avocado From Seed In 5 Easy Steps – With Tree Transplant Guide!

Choosing The Right Types Of Seeds

Several envelopes stuffed with fresh seeds for indoor germination.

We already talked about choosing healthy seeds. But there are other variables to consider. Some flower seeds germinate perfectly indoors. But others may struggle. Try to source local heirloom seeds. If you buy seeds online, buy cautiously and read many reviews!

Root vegetables like garlic are more tricky to start indoors and may require cold stratification. Our favorite fruit crops, like apples, blueberries, cherries, pears, and peaches, also benefit from cold stratification. 

It is also wise to consider the amount of space and light each plant cultivar will need to grow adequately.

Flower Seeds

Our favorite flower seeds for indoor growing include petunias, sunflowers, cosmos, marigolds, alyssum, zinnias, snapdragons, and celosia. Sow these seeds indoors in spring, around four to six weeks before the last expected frost date.

Keep the soil warm and evenly moist but not soaked. Aim for an indoor temperature of around 70 to 75 degrees Fahrenheit. When the seedlings emerge, provide plenty of light and watch for pests, like aphids, spider mites, whiteflies, and fungus gnats. (Believe it or not – some might find their way indoors.)

Harden your flower plants off when they’re ready to go outdoors. Expose them to outdoor conditions gradually for a few hours each day. Hardening your flowers will help them adjust to the chillier weather and avoid transplant shock.

Vegetable Seeds

Colorful vegetable seeds in paper envelopes.

Our favorite vegetables to start indoors include beans, cucumbers, eggplants, tomatoes, pumpkins, and zucchini. The ideal sowing times for these seeds vary depending on the cultivar and your location, so always read the seed packet for specific instructions.

Indoor-sown seeds typically require more care and attention than their outdoor counterparts, so provide them with the appropriate environment. Most critical are the temperature, natural lighting, and humidity levels.

We usually aim for at least six hours of direct sunlight, 70 to 75 degrees temperatures, and consistently moist soil, with an ambient 40 to 60 percent humidity, if possible.

Herb Seeds

Herb seeds are an excellent way to kick-start your indoor garden. Many popular herbs germinate perfectly indoors. Basil, rosemary, parsley, catnip, chives, cilantro, sage, and thyme are a few that come to mind.

The recommended sowing time for these herbs is typically in late winter or early spring, around six to eight weeks before the season’s last frost.

When sowing herb seeds indoors, warm and consistently moist soil are the two things you need most. Herbs prefer a warm location to germinate. So, a south-facing window or a heated germination mat is ideal. 

Related – Here’s How To Grow A Lemon Tree From A Seed: Germination, Care, And Harvesting Guide!

Supplies Needed To Start Seeds Indoors Without Grow Lights

Biodegradable peat cups with many baby seeds germinating within.

You can successfully start seeds indoors with the help of some basic supplies. You don’t need fancy gardening or horticulture gear. You only need the following items.

Seed Packet And Permanent Marker

Growing seeds inside is an exhilarating, entertaining, and rewarding project. But it can also get hectic if you’re disorganized. Track what you’ve planted to avoid confusion during transplanting time.

Always label your growing cups or pots. Otherwise, you can lose track of what seed is which. Mixing up cucumbers, squash, zucchini, beans, sunflowers, and pumpkins is too easy. Many baby plants look virtually identical!

The best way to label each pot is by using plant markers with a permanent marker to indicate what type of seedling it contains.

You can also use wooden popsicle sticks. Label each pot immediately after planting to avoid forgetting what plants grow within.

Use a permanent marker, as it must last throughout the germination process. Ensure the marker is waterproof and won’t smudge or wash away when watering.

Potting Mixes Or Seed-Starting Mixes

The mix should be sterile, well-draining, and lightweight to prevent fungal diseases and promote strong root development.

Some popular options for seed-starting mixes include sphagnum peat moss, vermiculite, perlite, coconut coir, and compost.

Brands like Miracle-Gro, Burpee, Jiffy, PittMoss, and FoxFarm offer seed-starting mixes specially formulated with a balanced blend of nutrient-rich or well-draining ingredients like perlite, sphagnum peat moss, and vermiculite. These mixes provide superb aeration, nutrients, and drainage for healthy seedling growth.

Seed Trays, Pots, Or Containers With Drainage Holes

Shoveling compost and peat into biodegradable paper growing trays.

I love peat pots and biodegradable growing cups the most. But you have other options. Seedling trays also work excellently. They have individual cells to help control the number of seeds per cell and promote root growth.

Seed trays made of plastic are a durable and affordable alternative. But always clean them thoroughly after each use to stop mold or plant gunk from spreading, which may affect germination.

A drip tray and clear plastic lid can help create a humid environment to help aid germination. The idea is for the drip tray to help catch excess water that drains from the containers, while the clear cover helps retain moisture and maintains a warm temperature for the seeds to sprout.

Heat mats are like cheat codes for homesteaders growing indoor seeds without a grow light, especially if you live in a cold growing zone or keep indoor temperatures chilly.

A heat mat can help increase the germination rate and speed up the process dramatically. Heat mats provide a constant source of warmth, which is often essential for initiating the germination process.

You will need seed trays, potting mixes, and plastic domes to get the most from your heat mat. Fill the seed trays with your potting mix and add the seeds according to the instructions. Offer them a warm splash of water. Then, place the plastic dome over the tray to help retain moisture and heat.

Rotate the seed trays every few days to encourage even growth. This constant and even heat supply will ensure your seedlings are warm, pampered, happy, and healthy.

Plastic Dome (Optional)

Tiny mango tree growing in a flower pot with a plastic bottle cover.

Plastic domes can give your baby seedlings a boost. This simple (and borderline-genius) tool can create a mini greenhouse effect, helping to keep moisture in and pests out.

You can make a plastic dome using nearly any clear plastic container – like a two-liter bottle chopped in half or a thin plastic cup.

Once you’ve planted your seeds in the mix and watered them, place the lid on the container and set it aside in a warm location.

Related – How To Grow A Peach Tree From Seed In 6 Weeks!

Sunny Window Or Spot In Home

South-facing windows provide the best and most intense light and are ideal for plants that need as much light as possible. On the other hand, plants such as lettuce or mint require less drastic lighting, making east or west-facing windows a suitable choice. Skylights can also make a marked difference in providing consistent light for your seedlings.

When looking for a location for your indoor seed starting, it’s also wise to aim for consistent temperatures. You’ll want to avoid placing your seed trays in areas that experience extreme fluctuations in temperature, such as near drafty windows or heating vents.

Peat Moss (Optional)

Starting seeds indoors is tricky. Using peat moss in your seed starting mix can help. Peat moss is a popular organic matter perfect for seed germination and indoor plant cultivation. It improves the soil’s drainage and aeration and helps create an excellent environment for your seeds.

A soil mixture of perlite, vermiculite, and peat moss makes a perfect homemade potting mix for seed germination. Mix the three soil ingredients in equal parts in a large container. Then, moisten the soil mixture with enough water to make it damp. Ensure it’s not too wet before filling your seed trays or pots.

Press the soil gently once you’ve filled your seed trays or pots. Use your permanent marker to label the trays or pots, then water them carefully, making sure not to overwater. Provide proper drainage by making tiny holes at the bottom of each pot or tray. And you’re ready to rock. 🙂

How to start seeds indoors.


Thanks for reading our guide about starting seeds indoors without a fancy light system.

We have a ton of indoor seed germination experience.

We germinate zucchini, squash, sunflower, bean, pumpkin, cucumber, and herb seeds indoors yearly. The process we’ve shared almost always works magnificently. We always end up with many pounds of healthy, delicious food.

What about you?

  • Are you going to grow a vegetable garden next year?
  • Have you tried germinating indoor fruit and veggie seeds without a grow light?
  • Do you find that a south-facing window is adequate for indoor seed germination?
  • What seeds give you the most trouble when germinating indoors?
  • Do you live in a cold growing zone? Does indoor seed germination help you get a longer growing season?

We’re diehard gardening enthusiasts and love hearing from like-minded homesteaders.

So, we hope to hear from you.

Thanks again for reading.

Have a great day!

Continue Reading:

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *