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The 5 Biggest Seed Starting Mistakes Made When Starting Seeds Indoors

When it comes to starting flower and vegetable plants indoors, avoiding a few big seed starting mistakes can mean the difference between sweet success, and total growing failure.

Growing plants from seed is one of the most rewarding experiences a gardener can have. Watching something you planted mature to a beautiful flower or vegetable plant simply never gets old.

Check Out Our Podcast On How to Start Seeds Indoors!

But many gardeners struggle growing plants indoors from seed. And more often than not, the issue usually boils down to a few mistakes that can easily be fixed with ease.

In today’s article, we take a look at 5 of the biggest and most common mistakes made when growing from seed indoors. And more importantly, how to avoid them for great plants!

The 5 Biggest Seed Starting Mistakes Gardeners Make

#1 Starting Seeds Too Early, Or Too Late

Starting seeds indoors at the wrong time is by far one of the most common mistakes of all when it comes to growing from seed.

Start seeds too early, and you’re faced with overgrown seedlings well before it’s time to transplant outdoors. But start too late, and plants may never have the chance to bloom or fruit by the end of the season.

Seeds started too late may never get large enough for transplanting outdoors until it’s too late.

So what is the answer? It all comes down to knowing your specific areas average last frost date. From there, simply count backwards the number of weeks required for seeds to be ready for transplant. And that is exactly when you should plant!

Almost all seed packets will contain this information right on the back of the packet. (See : Picking The Right Time To Start Seeds Indoors)

#2 Using Old / Stale Seeds

Your garden and flowerbeds will provide you months of blooms and vegetables. So why try to save a few cents using seeds that might be past their prime?

It is a seed-starting garden mistake that is easy to avoid by always using fresh, quality seeds.

Seed saving mistakes
Never keep seeds for more than a year. Fresh seeds provide better germination rates, and a better chance for healthy plants.

Old seeds don’t only germinate at lower rates, they can also have less strength and vitality as they grow. As a good rule of thumb, never keep or save seeds beyond one growing season.

And when saving seeds from your plants, always be sure to store in a cool, dry location. A cool, dark basement is a great choice – and in the refrigerator is even better.

#3 Using Inadequate Soil

Seeds need great soil to become great plants! Unfortunately, a big mistake many gardeners make is to use poor seed-starting soil in their seed trays. It puts plants behind the proverbial 8 ball right from the start!

seed starting mistakes

To germinate and grow well, seeds need lightweight, nutrient-filled soil that drains well. Those tiny cells of soil are a seed’s home for its first 6 to 8 weeks of life. And that soil need to perfect to promote strong root growth.

Never use plain garden soil or top soil to start seedlings. Instead use a high quality seed-starting mix with slow release nutrients. Product Link : Espoma Organic Seed Starting Soil

You can also easily make your own high-powered potting soil right at home. We have for years, and not only does it save money, it is a great way to fill your seed starter with all types of great nutrients. (See: How To Create The Perfect Seed Starting Soil)

#4 Starting Seeds In A Sunny Window – A Big Mistake!

Contrary to popular belief, it is not a good idea to start vegetable or flower seedlings in a sunny windowsill. The young seedlings indeed grow quickly to the light of the sun. But in the process, they become spindly and weak, even with constant turning.

windowsill plants
Seedlings in windows tend to be spindly as they try to grow quickly to the light. Windowsills are simply not a good place to grow flower or vegetable seedlings.

The light from the sun through a window is simply too far away. And young seedlings spend too much energy growing towards it, and not filling out.

It is far better to grow seeds indoors with artificial light. But no need to purchase fancy and expensive equipment. Ordinary fluorescent bulbs set an inch or two above seedlings as they grow promotes slow, steady growth.

vegetable transplants
We grow all of our seeds underneath ordinary shoplights. It keeps them both strong and straight, with slow steady growth.

We use our DIY homemade seed starting stand with a few shop lights to grow all of our plants from seed. And it works wonders to create strong, vibrant transplants! See : How To Make A DIY Seed Starting Stand

#5 Not Hardening Plants Off Before Planting Outdoors

Finally, the last mistake many gardeners make when starting seeds indoors is to not properly prepare the plants for outdoor life.

Plants grown indoors have had an easy life. And if they are simply taken out and planted directly into the soil, most won’t and don’t survive.

hardening plants off outdoors
Allowing seedlings to adjust slowly to outdoor life is known as the process of hardening off.

The process of hardening off prepares plants for life outdoors. Begin by setting plants out for a few hours to adjust to fluctuating temperatures and winds. Start this process a few weeks before plants will go in the ground.

As the days lengthen and warm, leave them out longer to continue to adjust. Finally, keep them out overnight as well as temperatures allow. (See : How & Why To Harden Plants Off Before Planting)

Your plants will “toughen up” and be ready when it comes time to be planted in their final outdoor spot.

Here is to avoiding the 5 biggest seed starting mistakes, and growing your plants from seed this year! Happy Gardening – Jim and Mary

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