Seedling mix - what are you growing?

Anyone have a favorite mix for seed starts?
Do you make your own or do store bought?
What ratios has worked well for your cold / warm crops?

I"m going to try 2.5" starter pots this year to avoid potting up.

What new crops will you try in 2022?

I am trying to figure this out myself and after five years, I still feel like I have no idea what I'm doing because I get really mixed results with my seeds. I spent some time googling and watching YouTube videos and I still don't know what's best. (It's looking asking a bunch of people for the best chocolate chip cookie recipe- they all seem similar but different enough that I can't decide which exact recipe to try.) So I welcome any advice about seeds starting mixes.

As for what I'm starting (as soon as I make up my mind about what seed mix to use this year), I went overboard buying a bunch of different tomato and pepper seeds to try this year. I can grow excellent cherry tomatoes but struggle with getting any larger ripe tomatoes. So I bought a bunch of seeds that were developed in cold northern climates. I've also finally found a sweet pepper that ripens for me and so I got a bunch of spicy peppers to try next. I'm also going to start some golden berries. I tried growing them the last two years but didn't start soon enough so I have got to get them in the dirt right now to have a chance at fruit I think. I'm going to be starting my eggplants this week too  And I'm planning on growing some basil just for inside until it warms up. That's it for the beginning of February. Most everything else I'll start in April.

Hey Jenny,

Thanks for your reply. Yes, I agree, much like chocolate chip cookies, so many variations out there but haven't yet found a clear winner.

I've been struggling for years to get tomatoes right and I'm hoping this is my breakthrough year! I used to live in Portland and I struggled to get my soil right, lots of end rot and green fruit. Now I live in Montana, so its colder but I build a greenhouse last fall and am hoping it helps me get a jump start.

My sister in law told me a funny tip today as we were nerding out on tomatoes... she swears by this and said when you transplant the lil babes into the ground, plant an egg underneath your tomato plant. Yep, a whole, uncooked egg. Adds calcium and fights off blossom end rot. I"m going to try this and see how it goes!

Here's some varieties I found here in MT...Glacier, Black cherry, Ida Gold, Peacevine Cherry. I may also try a F-1 hybrid or determinate. Heirlooms can be so tricky. MIGardener and Johnny’s has them.

Golden berries sound delish, I'll have to look those up!
I'll reply again once I figure out my seed mix. Happy planting

For tomatoes:
Exserted Tiger
Exserted Orange
Start S F1
Moravsky Div
Czech Stupice

Peppers
Hot Korean chili peppers

Okra
Sultani
Jing
Ultracross
Motherland
Kandahar Pendhi

Lettuce
Landrace from EFN

Mustard
Beni Houshi mizuna

Squash
Early Bulam
Butterfish
Canadian crookneck
North circle squash from EFN

Rhubarb
Dunfy rhubarb from EFN

Got some various early Russian determinates but we had septoria here last year and am afraid to plant them

Our current seed start mix is 1/3 coco-coir, 1/3 playground sand and 1/3 worm casting. Works very well.
You could use peat instead of coir, either will hold enough moisture and is sterile.
I have used perlite or vermeculite instead of sand. Both will allow drainage and air down there. Sand is just cheaper here.
You can use some finished compost instead of the worm castings... just some mild food for the little starts with some minerals and good bacteria.
 You have lots of options, just try to avoid  garden soil or anything that may contain pathogens/critters that could harm fragile seedlings.

For the flower seeds I have cold-stratifying outside right now, they are just in 50-50 coconut coir and perlite. For my veggie seedlings, I'll use 2:2:1 ratio of coir, compost, perlite. The block of compressed coir I bought was kind of expensive (like $16) but it expanded to be absolutely huge. Definitely worth it.

Thanks all for sharing!

Great tip on the coco coir...I will give that a try this year.

I start a good 300-500 seedlings yearly. Enough to be respectable but not as many as some. All my seedlings at this point are planted in Natures Care organic potting mix. It's consistent, easy to find, holds water but drains well, good for bottom watering hundreds of plants in trays, etc. I just adjust water levels as needed. I always plant in bigger cells that they stay in until planting time.

Dirt. Just garden dirt, and on a cold windowsill. I'm working on developing varieties that don't need all the STUFF to thrive, so this works. The house is kept at 60 degrees and as of this morning I had about a 50% germination rate from my tomato seedlings.

No peppers or watermelons up yet, but this is the first year I've done it cold for them so I didn't expect a high germination rate.

Lauren Ritz wrote:Dirt. Just garden dirt, and on a cold windowsill. I'm working on developing varieties that don't need all the STUFF to thrive, so this works. The house is kept at 60 degrees and as of this morning I had about a 50% germination rate from my tomato seedlings.

No peppers or watermelons up yet, but this is the first year I've done it cold for them so I didn't expect a high germination rate.

Interesting! What's your soil composition? My garden soil doesn't work for me for seed starting unless I mix coconut coir into it. Once I remove my soil from the ground and put it in any kind of a container, it turns into a clay brick within 24 hours. My hypothesis is that without all the soil life digging through and aerating it, the clay content just solidifies. And this is my soft loose garden soil that is nice and fluffy.

Jenny Wright wrote:
Interesting! What's your soil composition? My garden soil doesn't work for me for seed starting unless I mix coconut coir into it. Once I remove my soil from the ground and put it in any kind of a container, it turns into a clay brick within 24 hours. My hypothesis is that without all the soil life digging through and aerating it, the clay content just solidifies. And this is my soft loose garden soil that is nice and fluffy.

Primarily sand. But I've done this for years, and I harvest my own seeds so the plants are used to it. The plants adjust to the soil. Your seedlings, even if planted in that mixture with coir, probably do better when planted out into that clay soil. That's what they're used to.

One thing you may want to consider is planting under a cloche in the garden. The plants will have a little mini greenhouse but they'll have the advantage of germinating in the soil they'll live in. And no bricks.

Lauren Ritz wrote:

Jenny Wright wrote:
Interesting! What's your soil composition? My garden soil doesn't work for me for seed starting unless I mix coconut coir into it. Once I remove my soil from the ground and put it in any kind of a container, it turns into a clay brick within 24 hours. My hypothesis is that without all the soil life digging through and aerating it, the clay content just solidifies. And this is my soft loose garden soil that is nice and fluffy.

Primarily sand. But I've done this for years, and I harvest my own seeds so the plants are used to it. The plants adjust to the soil. Your seedlings, even if planted in that mixture with coir, probably do better when planted out into that clay soil. That's what they're used to.

One thing you may want to consider is planting under a cloche in the garden. The plants will have a little mini greenhouse but they'll have the advantage of germinating in the soil they'll live in. And no bricks.

Thanks for the advice! I've been collecting 2L bottles this year to try out as cloches with melons this spring so hopefully it works.

You know, I believe you are right about the seeds getting used to it over the years. I have volunteer cherry tomatoes that grow every year all over the place. I just dig them up and move them to where I want them for the year. I have had so many cherry tomatoes grow out of rock hard dried up pots of garden soil. Last year I was pulling out so many tomato seedlings from my other seedlings. Luckily tomatoes are easy to ID as babies.

I've been checking out Goodwill most weeks the day after they change which colored tag is discounted to $1 an item. I pick up every big, clear glass bowl (mixing bowls, punch bowls, etc.) that I find for $1 to use as cloches. I have more than 10 now. Now to keep the elk from messing with them ...

Carmen Rose wrote:I've been checking out Goodwill most weeks the day after they change which colored tag is discounted to $1 an item. I pick up every big, clear glass bowl (mixing bowls, punch bowls, etc.) that I find for $1 to use as cloches. I have more than 10 now. Now to keep the elk from messing with them ...

Hey that's genius! 😁 I've bought glass punch bowls at Goodwill for a dollar for parties but never thought about looking for ones suitable as cloches.

Carmen Rose wrote:Now to keep the elk from messing with them ...

Yucky, but maybe put pee on them?

Someone suggested using peat instead of coir - please please DONT. Peat is not a sustainable resource while coir is a waste stream from coconut harvesting. Here in the uk we are finally banning peat from manufactured seed/potting composts. We have lost a huge amount of peat bogs in recent times and that has wasted a valuable carbon sink.