A Complete Guide on How to Sow Seeds Indoors

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It is indeed a refreshing sight to watch the baby plant germinating from the seed. Have you ever wanted to grow your plants from their seed sprouting stage? For new gardeners, starting/growing seeds might look like an albatross around the neck. How much water do they need? What is the right medium to plant seeds? It starts to get confusing when you are a beginner in the field.

But don't worry, we are here to help.

This step by step guide on how to sow seeds indoors will make you master the craft. Sowing seeds indoors gives you the freedom to plant them any time of the year. You don't have to wait for the winter to be over.

These little buddies need a little bit of care and lots of love to grow into healthy plants. You might be wondering why sowing seeds is better than buying baby plants from a nursery. Going to a nursery is easier and saves time but you may not be able to find the plant you are looking for.

There are limits for the plant varieties stored in a nursery. But you can easily find the seeds of your favorite plant. There are more varieties of seeds available than baby plants. Another perk is that seeds are cheaper than baby plants.

If you are planning to grow a bigger garden with so many plants, seeds are the right option for you. Since you are there from the beginning of the plant's life, you can make sure that it grows healthy.

How to Sow Seeds Indoors – Step by Step

Step 1: Filling the seed tray

The first step is to find the right tray to sow the seeds. You can use seed flats or plug trays that are easily available in every nursery. Seed flats are single trays in which you can sow multiple seeds. It saves space because of the condensed size.

For crops like cabbage, celery, and onion using seed flats is a good choice. Plug trays have individual pockets for each seedling. It makes it easier to transplant when they are grown into healthy baby plants. In a plug tray, each seed can grow without being disturbed by the fellow seeds.

Radishes and leafy vegetables require plug trays with small seed slots. Use plug trays with bigger slots while growing beans, cabbage, broccoli etcetera.

If you can't get a seed tray, use food containers or some small cups. It would be better to use containers made of biodegradable substances to reduce plastic usage.

Clean the tray or container well and start filling the potting mix in it. Seeds require a special mix, unlike regular potting mediums. Use a pre seed starting mix or compost.

Step 2: Make tiny depressions on the tray to sow the seeds

You have to make sure that the potting mix is evenly distributed in each of the plugs in the tray. For this, take a flat wooden block and press it on the seed tray.

You can use your hands also. Remember to leave a tiny gap on the top of the seed tray. Now it's time to make depressions for the seeds. Use your finger or a pencil for this.

Step 3: Sowing the seeds

Now that you have prepared the seed trays, let's tuck in the seed babies. Place each seed gently and carefully to the depressions made in the mix. Choose the healthy and large seeds in the packet to plant. Cover the seed with a thin layer of seed starting mix or compost.

Step 4: Water the seeds

The seeds require the right amount (not less and not more) of moisture to germinate well. The baby seeds have no roots so they can absorb only the moisture from the surface. After covering the seed with the mix, gently spray some water.

Make sure not to disturb the seed while spraying water. The ideal soil in the seed tray will be a little damp but not wet. The soil should remind you of a damp sponge. Spread a thin plastic sheet above the seed tray.

Do not forget to flip the plastic sheet every morning. The dry side of the plastic sheet should come under and the moist side will be on top. This prevents excess moisture in the tray.

After the seedlings come above the soil, do not spray excess water into the leaves. Do not let the trays dry, consistent moisture is important since the seedlings are so delicate.

Step 5: Labeling the seed trays

After spraying the water, take each of the seed trays and label it. The label should include the name of the seedling and the date on which it was sown.

Step 6: Place the seed tray on the right spot

Place the seed tray in a clean and warm spot with sufficient lighting. It is always better to place the seed tray near the south-facing window. If it's winter season in your country, you will have to use artificial lights to provide sufficient light for the seedlings.

Do not expose the seed tray to direct sunlight. Make this process slow. Once the baby plants have sprouted some leaves, they are all set to enjoy the sun.

Step 7: Check the progress of the seeds regularly

Don't let them miss you. Monitor their daily progress in germination. Make sure the seed tray has the optimum lighting, temperature, and moisture. The baby plants will show up after a few days.

Bonus tip: How to foresee the germination rate?

Everything said on the seed packets might not be true. There will be sterile and non-sterile seeds in the same packet. Some may not germinate even if you took all the proper care.

You can assess the chances of germination by a simple test. Take some seeds from the packet and place them on a moist paper towel. Cover them properly and place the towel on a plastic bag. The plastic bag helps to retain the moisture in the towel.

Leave them for two or three days.

Open the towel after a few days and check how many of the seeds have sprouted. This will give you the percentage of the germination that can be expected from that packet of seeds.

Frequently Asked Questions on Sowing Seeds Indoors

1. How to make a DIY pre seed starting mix?

Potting mix is very important to grow healthy plants from the seeds. You can make your potting mix easily at home. Take two cups of compost, two cups of leaf mold or coconut fiber, and one cup of perlite.

Mix the three ingredients well and break any molds formed in the mixture. Adding a part of worm compost is also good for the seeds to germinate faster. You can make this potting mix in large quantities and store it for later use. Add a little water to moisten the mix before filling it into the trays.

2. How deep should we plant the seeds?

The depth of the depressions may vary for different crops. The seed packets usually instruct how deep you should plant the seed. If there is no such thing in the packet, you can use the rule of the thumb.

According to this rule, the depth will be the same or twice the width of the seed. But there are many seeds, like lettuce, that shouldn't be covered by a lot of soil.

3. How many seeds can be planted in one slot?

It depends on the crop you choose.

Seeds like beans are the hungrier ones on the list. They require more nutrients, so they should be sown individually. Whereas seeds like beets, radishes, peas, onions would love some company. They can be sown in clusters.

4. Why should we label the trays?

If you are growing a variety of seeds, it will get difficult to identify them after they are sown. Labeling helps you track the progress of the growth and analyze the problems if any.

5. Which seeds are best to sow indoors?

While choosing the seeds to grow inside, you have to consider the size of the seed and the time they take to germinate. Smaller seeds (lettuce, basil) do well indoors than in a garden. If they are grown in a garden, they might get lost in between the weeds.

But growing them inside gives a better root system to the plants.

For plants like tomatoes and peppers, it helps us to think ahead of the season. It takes two months for them to be transplanted to the garden. If we prepare the seedlings beforehand, it would save a lot of time.


There you go!

These are the steps to sow seeds that you shouldn't miss in your gardening adventure. Be free to be creative and experiment with different seeds. If you are an absolute newbie, try the easier ones, like a tomato, at first.

Gradually you can move to tougher ones. Don't forget to shower your little plants with loads of love. I bet you are going to love the whole process of sowing seeds. Let us know about your first seed sowing journey.

Happy gardening!