This post is all about seed starting in the NW and specifically in Portland. It covers what you need to start veggies from seed, where you can buy what you need, the simple science of starting seed (not from a dandies perspective but from a farmers) and a very basic applied methodology. If starting from seed is still too intimidating for you just swing by the farm and I’ll get you started in proper fashion. Enjoy!
The seed needs come from a reliable source and if you are purchasing it you should only buy the current years seed. I have primarily used Territorial Seed, based in Cottage Grove, for the past three seasons and I am a huge fan. Their seed tends to be a little expensive but you pay for what you get. When storing the seed you should keep it in a cool dry place and if you take good care of it it will last you a couple of years.
It is not worth your time to start seed with garden soil so fork over the cash to buy a seed starting medium. I buy mine from Concentrates (they are total sweet hearts by the way) located near Bob’s Red mill in deep S.E. and they sell for $10 a bag (1.5 Cubic feet). I blend three parts of the orange bag (an almost nitrogen neutral potting soil) to one part seedling medium (completely nitrogen neutral, purple bag). I do this for a couple reasons, one because most seedling mediums that you buy tend to crust over and impede the sprouts from breaking through into the open air. The second reason is that I want to dilute the amount of nitrogen in the soil from the orange bag because nitrogen promotes foliar growth in plants and too much growth in seedlings. That is why when most gardeners plant in a potting soil or compost they get leggy, tall weak plants, not because you don’t have enough light but because the soil is too nitrogen rich. Remember seeds don’t know photosynthesis, they don’t need light in the beginning. So Nitrogen is bad for seed starting. The three numbers you see on the orange bag refer to the NPK ratio (Nitrogen, Phosphorus, Potassium) of the soil medium. For seed starting you want those numbers as close to zero as possible. So now you know what to plant your seeds into, where to buy what you need and how much it costs.
You can see in the picture above. Watering can, bucket of soil, bowl (not needed if you have the tinest fingers in the world), a pen (because you need to write down what seeds you are starting on a tag otherwise you will forget), a tray (can be purchased at any garden store but if you want to buy the in bulk you can buy sets of 100 from Mckonkeys in Wilsonville. This is all you need besides what nature provides.
Okay, so here is how seed starting works. Veggie seeds need three things in order to germinate properly: air, water, heat (heat via soil conductivity). You get air from the space in the seedling medium that you are using. It has a bunch of stuff in it that is spongy (vermiculite, Pumice, etc..) and most importantly it has Peet Moss (which can be substituted for coconut coir depending on which one you think is more ethical) and peet moss in considered to be both hydrophobic (afraid of water) and hydrophilic (a lover of water) which means your little seed will have access to both water and air. You will add the water and you should wet the soil all the way through after you have planted your seed. Folks commonly say that it should have the moisture content of a wrung out towel, which I can’t figure out how to reproduce so don’t worry about it, just don’t let it dry out completely. With this mix you only need to water every two or three days at 70 degrees F. Now to explain heat, veggie seeds all germinate at a different temperatures. Peppers want the most heat, 80 to 90 degrees, so if you want to germinate those bad boys you will need an electric heating mat that you can purchase from any garden store. They are a touch expensive ranging from $30-$70 but peppers are expensive to buy so you can decide for yourself. Tomatoes need about 70 degree F to germinate and everything else is below that. Your average house temperature will be just fine and if you are concerned or want to feel more connected to the process you can buy a soil thermometer for a few bucks at any garden store and keep track of your soil temp. I use them all the time. As far as how deep you need to plant your seed into the tray don’t worry about it, I don’t. So now you know what a seed needs to germinate.