Top 10 Tips for Starting Seeds Indoors Like a Pro

Starting Seeds Indoors

Are you eager to get a head start on your garden this year? As I mentioned in the post Why February is the perfect time… it’s time to think about getting things planted! Starting seeds indoors is a fantastic way to kick your gardening season off with vigor and anticipation. Not only does it extend your growing season, but it also gives you greater control over the environment your plants are raised in. However, successful indoor seed starting requires attention to detail and some know-how. Here are the top 10 tips for starting seeds indoors like a master gardener:

Choose the Right Containers:

When starting seeds, choose containers that provide adequate drainage to prevent waterlogging, such as seedling trays or pots with drainage holes. We’ve used small paper or plastic cups, egg cartons, and all kinds of seed starting trays. Avoid containers that are too large initially, as excess soil can lead to overwatering and hinder seedling development. Larger containers also take up too much room, especially if you have a lot of seeds. As the plants grow larger, you can transplant them into bigger containers.

Select Quality Soil:

Invest in a high-quality seed starting mix or create your own by combining peat moss, perlite, and vermiculite. Avoid using garden soil, as it can compact and harbor diseases or pests that can harm delicate seedlings. We always buy organic potting soil. Usually in bulk from Planters Seed downtown, but sometimes from the big box stores.

Provide Ample Light:

Adequate light is crucial for healthy seedling growth. Place your seed trays near a south-facing window to maximize natural light exposure. Alternatively, use grow lights positioned a few inches above the seedlings for 12-16 hours daily. Keep lights on a timer for consistency. The amount of time they’re under the lights matters. Too much will harm them. They need rest, too!

Artificial light is fine when they are very young—this is called the cotyledon stage. But as soon as they start growing their “true leaves,” they need natural light or a full-spectrum grow light.

Maintain Optimal Temperature:

Most seeds germinate best in temperatures ranging from 65°F to 75°F (18°C to 24°C). Use a thermometer to monitor temperatures, and consider using a heating mat to provide bottom heat if your indoor environment is too cool. This is the first year we’ve used heat mats for seed starting, and I have to say – we should have gotten them long ago! It’s made a huge difference in how fast the seedlings are sprouting. I looked around and decided on a 2-pack of the VivoHome version. I did not get the available thermostat, but I might next time.

Starting Seeds & Watering – Be Wise:

Keep soil consistently moist but not waterlogged. Overwatering can lead to damping off disease, where seedlings wilt and die at the soil line. Too much water can also promote mold and harmful fungi. Water gently using a spray bottle or bottom-watering method to prevent disturbing delicate seedlings.

Provide Adequate Air Circulation:

Good air circulation helps prevent fungal diseases and encourages sturdy seedling growth. Use a small fan set on low to stir the air around your seedlings gently, but avoid direct airflow that may dry out the soil or plants. The point is so it circulates the air next to your seed starting trays, not directly at them. I use small clip-on fans for seed-starting and growing microgreens. If you have a ceiling fan nearby, that will probably be adequate; just don’t put your seed starting trays directly under the fan. You don’t want to dry out the soil.

Thin Seedlings Appropriately:

Once your seedlings have developed their first true leaves, thin them to ensure proper spacing and prevent overcrowding. Crowded seedlings compete for resources and can become leggy or weak. Use scissors to snip off excess seedlings at the soil level rather than pulling them out, which can disturb the roots of neighboring plants.

Fertilize Diligently:

While seed starting mix provides some nutrients, seedlings will benefit from a gentle fertilizer once they’ve developed their first true leaves. Use a diluted, balanced liquid fertilizer applied at half-strength every 1-2 weeks to provide essential nutrients without overwhelming young plants. I’ve had good luck with Espoma Organic Grow. I dilute it to half the normal amount when the seedlings are small.

I’ve been using Espoma products for about 15 years. They always work well for me, so I don’t hesitate to recommend them to other gardeners. If I had to pick a favorite, it would be Tomato-Tone. It was the first one of their product I tried, and I’ve gotten excellent results with it. It has helped to put hundred and hundreds of pounds of tomatoes on our table!

DoMyOwn is a supplier of Espoma products, and they have free shipping on all orders in the US. *We are an affiliate of DoMyOwn. That means if you click on the link & decide to purchase from them, we get paid a small commission, at no charge to you. As always, we appreciate everyone who helps support the blog with affiliate purchases!

Harden Off Before Transplanting:

Before transplanting seedlings outdoors, they need time to acclimate to outdoor conditions gradually. About a week before transplanting, begin exposing seedlings to outdoor conditions for a few hours each day, gradually increasing exposure to sunlight, wind, and fluctuating temperatures. I’ll write more about this in a later post.

Transplant Carefully:

When transplanting seedlings into the garden, handle them gently to avoid damaging delicate roots or stems. Plant seedlings at the same depth that they were growing in their containers, and water them well to settle the soil around the roots.

Conclusion

Following these tips for planting seeds indoors will set you up for a successful growing season filled with healthy, robust plants. Remember to be patient and attentive to your seedlings’ needs—they’re just babies! Enjoy the satisfaction of nurturing them, from tiny seeds to bountiful harvests.

If you have any other helpful tips to share, please do so in the comments below. Happy gardening!

Doc