How to Start Seeds Successfully Indoors

Show Notes
If you aren’t starting seeds, you’re limited to whatever you can plant directly into the garden and whatever starts you can pick up from your local garden center. Starting your own seeds opens up possibilities for growing new crops you couldn’t grow otherwise, better varieties for your garden and tastes, and earlier and better harvests to make it all worth it. In this episode of Granite State Gardening, UNH Extension’s Emma Erler and Nate Bernitz share proven tips and solutions for successfully starting your seeds indoors, from set up and germination to transplanting. Come for the accessible science, stay for the demystifying banter. Once you learn how to start seeds indoors, you can take your gardening to the next level. 

Featured Question: Homemade seed starting and transplant media

Featured Plant: Hyacinth Bean (Lablab purpureus)

Gardening Tip: Planting Depth

Background Reading:

Starting Plants From Seed [fact sheet]

Growing Vegetables: When to Plant Your Vegetable Garden [fact sheet]

Growing Seedlings Under Lights [fact sheet

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Email us questions, suggestions and feedback at [email protected]

Transcript by Otter.ai

Nate Bernitz  0:00 
Welcome to the Granite State gardening podcast from UNH Cooperative Extension. On today's show, we're talking about starting seeds indoors. in the show notes, you'll find a link to our fact sheet on seed starting, as well as helpful resources on when to start your seeds, indoor lighting and more. eight episodes in we're having a blast putting this podcast together and want to hear from you with your feedback, topic suggestions and gardening questions. Our email is gsg dot [email protected]. We really appreciate the emails we've gotten so far. And hey, if you're not already connected with us on social media, we're on Facebook and Instagram. Just search for ask UNH extension. Now let's get started with seed starting.

Greetings Granite State gardeners I'm Nate Bernitz, co host with Emma Erler of the Granite State gardening podcast, a production of UNH extension. Today we're talking about seed starting a practice that opens so many possibilities for gardeners, especially somewhere with a relatively short growing season like New Hampshire. By starting seeds. You won't rely on just whatever seedlings you can get your hands on from local garden centers and plant sales. And you won't be limited to what can be so directly in the garden. You'll have your choice of crops, flowers, and varieties galore to choose from all because you'll be able to provide ideal germination conditions indoors. Once you learn the science and know how of seed starting, you'll be at a whole other level of gardening and won't believe how limited you once were, with spring rapidly and mercifully approaching despite what Punxsutawney Phil says there's no time to waste. So let's get started. Emma, when it comes to seed starting, I want to first know the science, we always want to know the science first. So what are those ideal conditions for germinating seeds?

Emma E  2:05 
Well, a seed is is basically a shell or husk that's holding an an embryo on the inside. And in order for a seed to germinate, you need to have some specific conditions, you need to have moisture in you need to have light, and you need to have oxygen. And if you don't have those things, then the seeds not going to germinate. When we're talking about germinating seeds at home, we are providing that at least the moisture, at least moisture and oxygen in our seed starting mix that we're using. So that's that potting media that we've chosen to start our seeds in. And then light that's either going to be coming from a really bright window, or ideally actually from some sort of some sort of supplemental lighting system that you have inside your home.

Nate Bernitz  2:59 
Okay, so moisture, oxygen and light, not nutrients because these seeds already have the nutrients they need to at least get started, so to speak. So ideally, we're recreating these really ideal germination conditions indoors. We know the science, it's been researched, it's been determined, this is what you want to do for these seeds. So if you're doing everything right, what kind of germination percentages are you expecting? Like for every 100 seeds you're trying to start? Are all of them going to germinate? And what sort of practices that maybe aren't so ideal might bring that germination rate down?

Emma E  3:40 
Wow, that's a really good question. And honestly, it depends a lot on the exact plant that you're trying to propagate. Not all plants create viable seeds equally, some produce a lot more viable seeds than others. So germination rates, gonna vary a fair amount, and it's gonna depend a bit too on the age of that seed, exactly how it was harvested, how it was stored. So if you're buying seeds and packets like most of us do, those seed packets will will have been germination tested by the Seed Company. And on that packet, you'll see a percentage stamped on there somewhere that indicates what the germination percentage of that seed should be under ideal conditions. It's interesting though, because, like I said, some plants do you have a lot of really viable seeds. I mean, if we're looking at something outdoors, let's say an invasive plant like oriental bittersweet, the germination percentage of those seeds tends to be well over 90%. Whereas something like a paperbark maple, it's really only about 5%. So, you know, it helps maybe to know a little bit about the seed that you're starting. But if you have brand new seeds in a packet, you really just need to pay attention to what that jar percentage is listed on that packet and know that really, it would be very rare to have absolutely every seed germinate for you, that typically doesn't happen. But if you have some good quality seed, at least 80%, I think would be acceptable.

Nate Bernitz  5:17 
Okay, folks, don't go out there and just start germinating oriental bittersweet seeds, because you know, you're good germination, it's alright. It's not impressive. They're invasive, don't do it. When I go to the store, really any store right now, there are seed starting kits everywhere. These they're pretty cheap. They claim, you know, this is what you need. But I want to know from you, what do you actually need in terms of supplies, equipment, what kind of setup is really essential to get to get started and be successful with seed starting,

Emma E  5:53 
it could definitely be handy to buy one of those complete kits, but you're right, you don't need it. So to start with, I think it's helpful to figure out what sort of containers you want to start your seeds in. seed starting containers are typically on the smaller side, because you don't need to have a whole lot of potting media for a small seedlings root system. And they also are going to have drainage of some sort in them just just like you would for any ...