All about Starting Seeds Indoors

Soil Mix, Germination & Pricking out.

how to start seedlings indoors

Pretreating Seeds

I have heard so much fuss about pretreating Seeds.
Seeds' nature is to germinate - grow - and produce more seeds.
However, some types of seeds will germinate better if given a little head start.
I used to soak "sweet peas" to give them a head start. No difference.
Perennial flower seeds, however, germinate better in the spring if they get a cold chill ( stratify ) in the fridge until it's time to sow either indoors or outdoors. Presoaking, Stratification, Scarifying. Link takes you to Homes-n-gardens.

Sowing Timetable - Usually:

12 - 14 weeks:
onions, leeks, chives, pansies, impatiens, coleus
8 - 12 weeks:
peppers, cabbage family crops, petunias, snapdragons, alyssum.
6 - 8 weeks:
eggplants and tomatoes
5 - 6 - weeks:
zinnias, marigolds.
2 - 4 weeks:
cucumbers, melons, okra, pumpkins, squash.
Growing Timetables to print and keeping track of what works for me.
Like Peppers - I start mine in January - Zone6.
Tomatoes - I only need 6 weeks. Any longer they get too leggy.

How to Start Seedlings Indoors:

Seedlings need regular attention and it's also a "trial and error" experience.
If you start early and things don't work out, maybe you can start again, or just buy plants for the season. Seedlings need the right light, soil mix, heat and humidity to grow into healthy seedlings.
With practice - you got this! :)

When Should I start Seedlings Indoors:

Seeds started too early often results in unhealthy leggy and overgrown plants. Starting too late; it will delay flowering and fruiting.
Check your Hardiness zone and your seeds packet when to start your seeds. The best time to start seedlings will depend of your climate and your last frost date. So check with your seed packet.
In zone6 I start most of my seeds 6-8 weeks, before my last frost date, except for peppers.
I do most of my sowing in March and peppers in January to plant around May 21.

Seed Starting Mix:

I just use whatever Costco has, but last time I used their potting soil mix, my house was infested with fungus gnats.
Now I either buy sterilized seed starting soil or I sterilize my own.
You can take a small amount of soil and pour boiling water on it to kill all eggs and whatever MicroGro potting mix has in it. You can also microwave small amount of soil.
Place 2 pounds of moist soil in a small plastic bag, put bag in a microwave safe dish, just in case the bag breaks. Cook for 2 and Half minutes on High Power. Do ten pounds of moist soil for about 7 minutes.
After sterilization let the soil cool and store in sealed container.
After microwaving the soil, clean the microwave thoroughly, especially around the door seal.

Paper Towel Method for Germination:

Pre-sprouting seeds:
First spread your seeds on a double layer of damp paper towels.
Roll the towels carefully so the seeds won't bunch up and touch each other .
Label the seed roll.
Place the rolled paper towel with seeds in a plastic bag and keep it in a warm place until germination occurs.
Check every couple of days until germination occurs.

What do you do after germinating seeds on paper towel:

This is the part I don't like. :)
I use a pair of tweezers and tweeze the tiny little sprouts from the paper towel and plant them in pots.
I like using this technique to test my old seeds viability. Saves me a lot of guess work. :)

How big should the seedlings be before pricking out:

I like to replant my seedlings when they are still small.
I wait to see my plants first true-leaves and then I move them. They seem to transplant to bigger pots better for me when they're still small.

Starting Seeds Indoors with Grow lights:

This is what I'm doing now.
Nothing fancy, just ordinary shop lights. As I start replacing the shop lights I hope to replace them with LED grow lights. I am not buying the expensive grow lights either. I just want to get rid of the fluorescent tubes.
So, I bought some wire shelves from Costco. I adjusted the shelves for germinating seeds and some for seedlings. It is easy to adjust the lights on the wire shelves with "S" hooks. I don't have a heat-mat yet, but it works fine without it.
The best part about having grow-lights is that I have designated spot just for my plants. I have my grow-lights on a timer. I have my timer on for 16 hours during the day and off at night.

Starting Seeds Indoors Without Grow lights:

I still grow seeds and plant clippings on my windowsills.
The seeds take longer to germinate and grow, but putting the seedlings on a heat-mat really helped. However, until lately that's where I started all of my seeds on the windowsill, without a heat-mat. When I planted all of my plants outside in the spring and filled my freezer and shelves full of food in the fall, it made me proud. :)

Transplanting Seedlings Outside:

This cannot be rushed. :)
First you have to harden your seedlings before planting them outside.
I put my plants on a rolling cart and roll them outside for a couple hours a day for about a week. Bringing the plants in at night. A cloudy warm day works best for me.
Increase the out hours for hardening during the day. After a week of this my plants had enough of "mollycoddle". When transplanting; - hold the seedling by first leaves ( cotyledons ) and not the stems. Use a chop-stick, pencil, dowel, spoon to loosen the soil from the roots and lift the plants to the their new place. Set most seedlings just slightly deeper than they were in their original containers.
Tomatoes: I plant them as deep as I can, because tomatoes will grow roots along the stems as well.
Aftercare:
Keep an eye on newly transplanted plants for a few days until they adjust to their new home. Water right after planting and try to plant on a cloudy day and if it rains I consider that a blessing. To me, that's my key to my transplanting success.
Or I plant after supper, that way my plants will have a chance to acclimate to their surroundings before the hot sun arrives in the morning.

How Long can Seedlings Stay in Trays:

I think about 3-4 weeks. You will know when it's time to move them outside. The leaves turn yellow and you just can't keep them watered, because the roots have used up all of the soil and the nutrients.

How Big should seedlings be before transplanting outside:

I like my plants as big as I can get them by May 21. First I start planting my cool crops.
Then I direct sow beans, cucumbers, lettuces, melons and pumpkins. Then I concentrating on planting my fussy plants like: peppers and eggplants.
Some vegetables - like corn - I can't grow at all, because the Raccoons get them before I do.

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