How to Start Seeds Indoors for Best Results

Are you wondering which plants you can plant now for your spring garden? The time is now to do this, and I’ll show you how to start seeds indoors so they will be ready to be transplanted into the spring garden once the last frost of the season has passed.

Starting seeds indoors is one of those things that becomes a bit of an itch once you have gardened for a year or two. It’s amazing how much more expensive it is to buy plant starts than to grow your own.

It occurs to you that if there are 25 seeds in a packet for $1.99, that’s 25 plants for $1.99, providing they all sprout. And even if they don’t, more than 6 plants for $1.99 is much more economical than purchasing 6 plants for $2.97! Right?

Ok yeah–that’s all true. However, it’s not as easy as just dropping seeds into the ground and giving it a little water. There’s a method to starting seeds indoors, and if you don’t follow at least most of the method, even your seed money will go to waste. There are other things you will need to start seeds, which I’ll share with you.

How to Start Seeds Indoors (so you don’t waste them)

Below is a list of all the plants that start well indoors, and can be transplanted into your spring garden. At the bottom of this post, I”ll have a list of these vegetables with the best times to start them indoors for you.

• Artichoke
• Asparagus
• Beets
• Broccoli
• Brussels Sprouts
• Cabbage
• Cauliflower
• Celery
• Cucumber
• Eggplant
• Kale
• Leeks
• Lettuce
• Melons
• Onions
• Peppers
• Pumpkins
• Spinach
• Squash, Summer
• Squash, Winter
• Swiss Chard
• Tomatoes
• Watermelon

Collecting Your Supplies

You don’t need many things to start your seeds, but it is best to make sure that you get supplies that will help you get the best results for your buck.

Seeds

I recommend non-GMO, open-pollinated heirloom seeds for planting. This type of seed ensures that you will be able to collect seeds from the plants you grow with them, which will help you create your own seed bank, saving you money for years to come.

Recommendations for Seed Sources
SeedsNOW!
Amazon.com
Baker Creek

Planting Medium

There are a few options for seed starting containers. I prefer to use peat pellets, usually the type that come in flats of 36 or 72, for most small seeds. These are the easiest to plant and transport around, though using them does require you to “plant up” at least once before you plant them outside.

If you would prefer to plant in small containers, you can get those and a good seed starting mix. Don’t use potting soil or dirt from your garden outside. Seedlings are delicate, so you want to give them the best opportunity to live. Using a sterile medium will be key.

Options for Peat Pellets:
Jiffy Peat Pellets Tray 12 plant starter kit (my recommendation for this course)
Jump Start Pellet Tray 36 plant starter kit (perfect size for using with grow light box; this item is less expensive at your local garden center)
Jiffy Peat Pellet Tray 72 plant starter kit (Will need two heat lamps or grow lights if you use this; not recommended for use with grow light box. This item is less expensive at your local garden center.)

Seed Starting Mixes:
Jiffy Organic Seed Starting Mix (my recommendation)
Miracle Gro with fertilizer (if you want something with fertilizer)
Coco Coir Brick (if you’d like a less expensive option)

Container Options:
black planting trays
peat pots, 3 inch
plastic pots, 3.5 inch
10″x10″ trays (perfect size for using with grow light box)
10″x20″ trays without drain holes (can be used with plastic pots; will need two heat lamps or grow lights if you use this; not recommended for use with a grow light box)
10″x20″ trays with drain holes (for use with only seed starting mix)
dome lid for 10″x20″ trays (or you can cover with plastic wrap)

Heat

Heat can be important to sprouting some seeds, but it’s not for all. Tomatoes, peppers, and most herbs will germinate quicker with bottom heat. You can use a heat mat or put your flat of seeds on top of the refrigerator, or even over a heater vent. If you use a heater vent, you’ll want to raise them up about 6 inches off the vent, as they would dry out too quickly otherwise.

Why not use a sunny window? You can, but if it’s not warm inside of your home, it may not be enough heat for heat-loving seeds. Not to mention, a sunny window really isn’t the best choice for seed sprouting because the light is too far from the plants, which causes them to grow leggy.

Light

Light isn’t as important to seed starting as it is to the care of your seedlings. The reason I mention it here is because it’s important to have light at the ready when your seeds do sprout.

Seedlings need light from the time they sprout to the time you plant them outdoors, and beyond. Close-up light, about 2 inches from the top of the plant, is an important component for nurturing healthy, strong seedlings.

You can use ready-made grow lights, but they can be very expensive. I prefer to use a grow light box (or two or three) for sprouting and growing my seedlings.

The box is lined with aluminum foil and reflects the light to all sides of the plant, and it keeps heat and moisture in, which is mostly a good thing. It can also allow bacteria and mold to grow, so you’ll want to be careful when using the grow light box.

Options for light:
Ferry Morse Grow Light (use two of these side by side when using the 72-ct peat pellet tray)
Root Farm Grow Light (looks like a 10″x20″ tray would fit nicely under this)
Grow Light Box (instructions in the link)

A Planting Calendar

Once you have all of your supplies together, you will need something to guide you when to plant your seeds indoors. Each plant is different, and requires a different amount of time to grow before it is able to survive a transplant into its “forever home”, your garden bed.

If you are inclined to use a garden planner, I have one that I use every year that includes a planting calendar, PLUS all the information needed to start a garden from the ground up. You can check that out here.

How to Start Seeds Indoors

Planting is really easy. A good rule of thumb is to plant tiny seeds by sprinkling them on top of the wet soil, leaving them uncovered. When I say tiny, I’m talking really tiny, almost dust-sized.

Small seeds, like tomato, basil, lettuce, and other similarly-sized seeds need to be planted about 1/4″ below the soil, and covered lightly with soil. For large seeds like beans or pumpkin, plant about an inch below the surface of the soil and cover well.

Peat Pellets – you will first need to prepare them for planting according to the instructions on the container. Once ready, open the netting enough to loosen the soil on top a bit, then plant your seeds.

Containers – Wet your seed starting mix until it’s wet, but not waterlogged. Pack your containers with the mix, then plant your seeds.

Growing Your Seedlings

Depending on the seed and its germination rate, your will see sprouts sometime inside of a week or two. At this time, you will want to make sure that you get them under the light, about two inches below.

Watering Your Seedlings

Always water your seedlings from below. This is easiest when you have your seedlings in a container, such as foil trays or plastic storage containers (no lids). Add your water to the bottom of the container and allow the plants to “drink” up all the water.

If they drink it up quickly, add more water. Whatever is left after 15 minutes, carefully pour off so the plants won’t sit in the water and rot.

Moving Your Light

As your seedlings grow, you will need to adjust the light for them. Try to keep the light about two inches above the tops of the plants. This is much easier if you are using ready-made grow lights. However, if you are using a grow light box, you will be moving your plants up and down, rather than the light itself. I do this by putting plastic baskets or shoe boxes beneath the plant flats, and adjusting every few days.

Fertilizing Your Seedlings

Seedlings won’t need to be fertilized for the first two weeks or so of their lives. Usually the seed will have what it needs for a while before they are hungry again.

At about two weeks old, start feeding them with an all purpose, water soluble fertilizer prepared at about 1/3 or 1/2 strength. Alternatively, you can use Vermisterra worm tea (or you can make your own with worm castings), and feed at about 1/2 strength. Fertilize your seeds in the same way you water them, from underneath.

Suggestions for fertilizers:
all purpose plant fertilizer (I use this type)
worm castings (if you would like to make your own tea)
worm tea (if you would prefer not to make your own)