How & When to Start Seeds Indoors? 11 Simple Steps | House Grail (2024)

For those looking for a faster harvest, starting seeds indoors is the way to go. In cooler areas, this may be the only way to ensure a harvest during the growing season, especially for veggies that take longer to grow. Luckily, starting seeds indoors is not terribly difficult. It isn’t much different from planting seeds outside, only you’ll have a transfer to worry about.

That said, not all seeds can be started indoors. For instance, carrot plants do not like having their roots messed with. Therefore, they are not a good candidate for starting indoors.

Before you begin your garden seeds inside, though, there are several preparatory steps you need to consider.

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When to Start Seeds

When you should start seeds depends on the type of seed you have. All plants grow at different rates, so you’ll need to start your seeds at separate dates according to their type. Usually, seed packets state when you should start the seeds indoors, typically according to the last frost date in your area.

Therefore, it is helpful to know the last frost date in your area before you begin. You can find this date online with little trouble or just use the Almanac calendar.

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The 11 Simple Steps on Starting Seeds Indoors

1. Buying Seeds

Before you begin, you’ll need to acquire the seeds you want to plant. You can find seeds at many different locations, including local home improvement stores and online catalogs. Seeds vary in price immensely, but most common seeds are pretty inexpensive.

Seed’s purity and quality are governed by laws. In other words, you cannot sell seeds that won’t germinate. Therefore, the place you purchase seeds from isn’t terribly important. Even if they are off-brand, the seeds should germinate just fine.

You can store leftover seeds for next year. It is often best to store them in a cool place, such as a fridge. Adding a packet of silica gel can help keep the humidity low, preventing germination.

2. Location, location, location

Next, you need a place to start your seeds. Often, this is a bit more complicated than it may appear. The place should be free from heavy traffic to prevent accidents, as well as drafts and excessive heat. Preferably, you should prepare the area so that any spills won’t be a problem. (In other words, don’t start seeds over a carpet!) How much space you need will depend on the number of seeds you’re starting, but this factor is also important.

The temperature should be room temperature consistently. A garage often isn’t the best choice for this reason, but a basem*nt may be.

While many people may consider starting plants on a windowsill, this is not recommended for a few reasons:

  • With only one direction of sunlight, plants will often become extremely tall and thin, making them unsuitable for the outdoors.
  • Water damage can occur from watering the plants.
  • Heat builds easily around windows, drying out the potting mix.
  • The temperature will often not stay consistent.
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3. Choose Containers

You may have a few old, small containers nearby. In that case, you may not need to purchase new containers for these plants. However, most people will need to purchase seed-starting containers of some sort. We primarily recommend commercial seed starting containers, as they are very small and often work best.

These containers are reusable, so you can continue to use them every year. However, they may need to have drainage holes poked into the bottom. You should also sterilize the containers before each use to prevent diseases and mold.

You can also make degradable pots from newspapers or purchase commercial options made from shredded wood or peat. These options are recommended mostly for plants that don’t transfer well, as you won’t really have to transfer them.

To promote germination, we recommend putting a clear dome over the container. Often, commercial containers come with these domes. However, you may have to purchase them separately or build your own. When the seedlings are tall enough to touch the dome, remove it so that they can continue to grow normally.

4. Purchase a Potting Mixture

Potting mixtures are not the same as soil. Most potting mixtures are a mix between peat and vermiculite. Luckily, this mixture is great for starting seeds, so it’s what we recommend. Using these mixes instead of dirt from the outside ensures that your plants won’t have to contend with diseases and weeds, which can be brought in from outside.

Plus, these mixtures are lightweight and often hold water well.

Always fill the pots and water the mix before adding seeds. Usually, the mixture has to adjust a bit before seeds can be planted.

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5. Adding the Seeds

After the potting mixture has settled, you can sow your seeds. You should follow the directions on the seed packet, as each type of seed will have slightly different needs. Plan some way to identify each seed. Often, pieces of paper can be used, or you can write on the containers with a permanent marker.

If a seed requires light to germinate, be sure not to bury it too deeply. Otherwise, it may not get any light. Plants that need darkness to germinate should be placed somewhere dark. You may have to keep different types of seeds in different places for this reason.

If you’re utilizing older seeds, use two or three per container. They tend to have a lower germination rate. You can always thin seeds out later if necessary.

6. Add Light

After your seeds are planted, they typically need a steady source of light. Even if plants require darkness at first, light is required once they germinate. We never recommend relying solely on natural light, as cloudy days can throw a wrench in your plan. Instead, fluorescent lights are typically a suitable option. However, grow lights are by far the best option if you can afford them.

Set up your lights so that they can be moved as your plants grow. You want the light as close as possible to the plant, but you may have to move them upwards as the plants grow. About 2 inches from the top of the plant is ideal, as this prevents long and leggy sprouts.

Plants only need 12 to 16 hours of light, depending on the seeds. Do not leave the light on constantly, as plants need some darkness. They have a day/night cycle just like humans. If you commonly forget to turn the light off, you can add a timer to the lights that automatically turn them on and off at certain times.

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7. Ensure Proper Heat

Plants need a decent amount of heat to grow properly. Usually, this isn’t a huge deal, as our houses are usually warm enough for most plants. However, you may want to consider adding a consistent source of heat underneath the plants to encourage plant growth. When the potting mix is kept warm, seeds will germinate faster and root systems will be healthier.

Furthermore, adding electric heating sources can kill bacteria and other pathogens. Some of these pathogens are harmful to sensitive seedlings, potentially killing them when they sprout.

Keep heating mats on constantly, including during the night.

8. Water

Of course, seedlings also need water. We recommend keeping soil moist while seeds are germinating— but not wet. Too much moisture can cause rot before the plant even gets going. Most gardeners use a water bottle to apply only a small amount of moisture. You can also set pots in a tray and allow water to move up from the tray.

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9. Time to Transplant!

As your seedlings grow, you may need to move them into bigger pots. Large peat pots are recommended, though many budget gardeners also use plastic cups with a hole cut into the bottom. Transplanting can be a tricky business, as seedlings are easily damaged during the process. To prevent damage, never tug on a plant while transferring it. Instead, scoop out the roots and place the plant gently into the new pot.

Never hold the plant’s stem for support. Instead, support the plant from the bottom where the roots are located. Using a spoon can often make transplanting much safer, as it allows for scooping and supports the tiny plants well. Either way, holding a plant by a leaf is better than the stem. A plant with a lost leaf can continue to grow, but a plant with a damaged stem cannot.

If your plants need to get particularly large before transplanting, consider adding extra light. Often, one light is not enough for several large plants.

10. Harden Seedlings

Before you consider moving your plants outside, they need to be hardened. Suddenly moving a plant outside can easily lead to it dying, since it isn’t used to wind, fluctuating temperatures, or sunlight. Therefore, slowly introducing your plant outside helps ensure that they survive the transition.

You’ll need to start this process a couple of weeks before you plan to plant. Start with placing the plants outside for a few hours in mild temperatures and wind protection. Whenever it gets cool (or hot), bring the plants back inside. Slowly elongate the time the plants are outside, introducing them to more wind and sunlight.

Preferably, plants should be left where they will be planted for a few days before you put them into the ground. This ensures that the plant can handle the area. If the plant begins to suffer, you can bring it back inside and continue with the hardening process.

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11. Planting

Finally, it is time to place your plants in the ground. We recommend planting in the afternoon after the sun has already peaked. Choose a cool, easy day for the plants, as the transplanting process can be stressful.

Even after hardening, plants may wilt after transplanting. This wilting is normal. In most cases, plants will recover after only a few days. You can use covers to help the plant recover and give it a break directly after transplanting.

Otherwise, plant according to the instructions on the seed packet.

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Conclusion

You don’t need to start seeds indoors for all plants, but many will benefit from an easy growing period inside. Usually, this process requires more work than planting seeds directly into the ground, as you’ll have to transplant them at some point. However, it does help you control the conditions easier, which helps bring about germination.

Keeping a calendar of when each type of seed needs to be started and moved outside can be helpful. Because each plant is different, they cannot all be started or moved at once. To keep things straight, a calendar is highly recommended.

Featured Image Credit: Art_Pictures, Shutterstock

Contents

How & When to Start Seeds Indoors? 11 Simple Steps | House Grail (2024)

FAQs

What month is best to start seeds indoors? ›

Mid-March is the best time to start many vegetables and annual flowers indoors for transplanting outside once the threat of frost has passed.

How do you start seedlings indoors for beginners? ›

How to Start Seeds Indoors in 4 Easy Steps
  1. Fill a large bowl with seed-starting mix and mix in a little water to evenly moisten the soil. ...
  2. Place your seed tray inside the drip tray and fill each cell to just below the top with soil.
  3. Sow your seeds. ...
  4. Cover the tray and place it under your lights on the heat mat.
Feb 10, 2023

Can you start seeds indoors too early? ›

It is tempting to be thinking about starting seed now especially when we have sunny weather in the 60s. However, January is far too early to start most seeds and sowing seeds too early is just as bad, maybe worse, than starting them too late. You waste your time and money when you start seeds too early.

Can you use egg cartons to start seeds? ›

You can use egg cartons as a seed-starting tray! Depending on the type of carton you have, you can even cut apart the individual sections and plant them, as the carton will biodegrade. Be sure to poke small holes for drainage, and put the cartons on a tray or in a shallow pan to catch any residual water.

Is February too early to start seeds indoors? ›

If you can't wait to sink your hands into the dirt, don't wait any longer—at this point, you can begin planting some of your favorite veggies! There are plenty of seeds that you can start indoors in February, and even a few that you can direct-sow outdoors.

How do you know when to start seeds indoors? ›

Once you know your growing zone, look at the back of your seed packet to see how many days to germination. "Now, count backwards from the date of planting to determine when to plant," says Spoonemore. "Most plants need at least six weeks from planting to moving outdoors.

Where is the best place to start seeds indoors? ›

Now, you need to add heat. Since sunlight is not essential at this point, your seed trays can be placed wherever it's warmest in your house, such as an attic, bathroom, laundry room, or kitchen. If your seedling pots stay covered in a warm nook, the low humidity will keep your seeds happy until they sprout.

Do I need grow lights to start seeds indoors? ›

The natural light from a window is seldom enough for good, strong seedling growth. They will usually stretch and lean towards the light and will not produce sturdy plants. Sowing seeds indoors under fluorescent lights is the easiest way for the home gardener to control growing conditions and grow healthy transplants.

Where is the best place to start seedlings indoors? ›

If you're starting only a few plants and have roomy window sills, a south-facing window may be all the growing space you need. Start seeds in small, individual containers.

Is January too early to start seeds indoors? ›

It's still too early for many Northern states to start their transplants indoors, but some warmer Southern states are ready to get going! Tomatoes, Peppers & Eggplants (Zones 8-10): If you live in Zones 8-10, get a head start on the growing season by starting your tomato, pepper and eggplant seeds indoors.

Is it too late to start seeds indoors in May? ›

You may think it's too late to grow all your favorite vegetables from seeds, but warm May temperatures have made the soil perfect for sowing seeds. Warm soil will allow for fast germination and growing plants! Good choices are summertime kitchen garden staples like squash, beans, cucumbers and melons.

What happens if I seed too early? ›

If done too early, some seed will germinate late in the season and those immature seedlings often won't survive the winter. Put down your seed while the ground is not frozen, but is still cold enough so germination of the grass seed will not occur until next spring.

How long can seedlings stay in trays? ›

As a general guide, after your seeds germinate they can grow in smaller (1.5″ cell trays) for about 2-3 weeks, in larger 2″ trays they can grow in them for about 3-4 weeks before needing to be transplanted. When it's time to transplant, wet your seedling tray soil & your garden's soil. This makes the soil stickier.

Can you grow seeds in used coffee grounds? ›

Mixing coffee grounds with soil can be beneficial for your plants as it adds organic matter and nutrients like nitrogen, potassium, and phosphorus. But coffee grounds are acidic, so if you have plants that prefer alkaline soil, it may not be the best option.

Which month is best for seed germination? ›

Therefore, January and February are the best time to start a fresh green year. There are several cool weather seeds that you can grow during these two months.

Can you start seeds indoors year round? ›

Starting seeds indoors during the winter is a great way for gardening enthusiasts to keep their sanity during the winter. It is also a perfect means for getting a jump start on the spring growing season. Seeds cost significantly less than seedlings and offer a much greater variety.

How early can I start tomato seeds indoors? ›

Aim to start tomato seeds indoors about six to eight weeks before your last frost date. So if your expected last frost date is May 10, for example, count back at least six weeks to March 29 as the day you need to get your tomato seeds planted.

What month should you seed? ›

Timing is everything when it comes to seeding your lawn. If you have cool-season grass, aim to start seeding in late summer or early fall before freezing air and soil temperatures hit your area. Start the seeding process in the late spring or early summer for warm-season grass.

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