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The past few years have seen a noticeable increase in the number of people choosing to grow food in their backyards. Eighteen million new gardeners have joined the ranks of seasoned veterans planting and harvesting homegrown food. Seed catalogs, websites, and local home and garden stores now offer a broad selection of possible choices for the home gardener. 

Knowing which seeds to select depends on a few variables such as first and last frost dates and growing zone. In this episode of Cornell Cooperative Extension’s ‘Extension Out Loud’ podcast, Stephen Stresow of Cornell’s Garden-Based Learning program discusses some key factors to consider when selecting seeds.  

According to Stresow: “It’s all about right plant, right place.” His advice when evaluating seeds for your garden: “My personal advice to gardeners is, I like starting off with stuff that’s easy to grow.” 

Choosing the right seed for the right place can feel overwhelming for new gardeners. Hybrid, organic and open-pollinated are just some of the options for individual varieties. Sorting through these possibilities is made easier by Cornell’s Vegetable Varieties for Gardeners website. This site crowdsources ratings based on gardeners’ experiences with different varieties. Used in combination with the Selected List of Varieties for Gardeners, which includes data from campus research and test plots, choosing the right seed for the right place becomes much easier. 

Stresow also discusses gardening resources that are available through Cornell Cooperative Extension offices across New York State. “One of the great parts of gardening and seed saving is not just having these great crops-- these great genetics,” he said. “It's that community that you build through saving seeds, sharing information, sharing stories, and the historical value of some of these crops and varieties that we might not know about.“ 

Listen on:

PAUL TREADWELL: Welcome to Extension Out Loud, a podcast from Cornell Cooperative Extension. I'm Paul Treadwell. And it's that time of year. Seed catalogs have arrived. The days are slowly getting longer. And we look, with longing and hope, to our backyards, anticipating the day when we can finally plant the first seeds of the season. And so many seeds to choose from, as we flip through the pages and browse websites-- a cornucopia of potential boundless in its diversity and promise.  

Knowing what seeds to choose can feel overwhelming. But to help us sort through the options and decipher the nuance of growing zones, soil types, and more, I'm joined by Stephen Stresow of Cornell's Garden-Based Learning program. We talk about a number of resources that can help you plan and plant your garden, so be sure to check the show notes for links to those resources.  

And Stephen, if you could just introduce yourselves to our audience and let them know a little bit about you.  

STEPHEN STRESOW: Hello, everybody. My name is Stephen Stresow. I am a master's student here at Cornell University working with the Cornell Garden-Based Learning and Cornell Small Farms program. A lot of my research focuses on sustainable vegetable management. I should mention I study plant science. So it's really fun to go from the morning lectures on molecular biology and how plants think and do what they do and then to do some of the more community outreach-based things with these different programs at Cornell-- so really has the best of both worlds.  

PAUL TREADWELL: Great to have you join us. We're here today to talk a little bit because it is that time of year when we start thinking about seeds, just wanted to get some basic information about seeds and selecting seeds for your garden. I know that seed catalogs have started to show up. And if you flip open any random seed catalog, you're going to be-- I find myself both dazzled and overwhelmed by the selections. So I have a seed catalog that has, what, 50-some odd different varieties of tomatoes. So if I'm getting ready to think about starting my garden, what are some of the key things to look for when I'm looking at different kinds of seeds? Can I ask that question?  

STEPHEN STRESOW: Yes. That is a great question. And I too find myself overwhelmed a lot of times. And I have a multipronged answer. One, it's a great question, as part of my master's work is taking a lot of these different information, varieties, then putting them into a seed catalog just for New York state for New York gardeners so they can select varieties that have already been tested-- tried and true.  

The second part is it's all about right plant, right place. What makes a good variety in upstate New York is going to be different from what makes a good variety in Georgia or in Texas or in California. So one of the first things that you want to think of is your space-- your actual garden-- because there's some varieties that are going to grow really great in containers as opposed to directly in the ground. And that could just be for space requirements. That could just be some plants are smaller and more compact. So that's the first thing you want to think of.  

And then the second thing that you want to think of is your garden itself. Not just the space, but how much shade do you get? How much sun do you get? On those seed packets, does it say that this plant must have a trellis, or that you have to do anything special with it? And if you're a beginning gardener, you might not want to have to deal with trellising your bean plant. So if you don't have that much time, you might want to go with a bush variety instead of a pole variety-- same thing with tomatoes.  

And on that note with space, that goes on choosing the plants that you personally like to eat. If you don't like hot peppers-- you don't like jalapenos-- why would you want to grow them? And then portioning space in your garden-- if you want to grow corn, that's great. Corn takes up a lot of space in that garden. I know this answer is a lot of things that depend on the garden, and we haven't even got into the plant themselves. So I promise we'll get there in a moment.  


Another thing you want to think of is on that note of personal preferences is, maybe, novelty. I personally like growing varieties that might be hard to find at the grocery store. It might be hard to find at the farmer's market. One variety that comes to mind is lemon cucumbers. Most people haven't heard of lemon cucumbers. And they are a variety of cucumber, then the fruit looks like little tennis balls. And they're super delicious-- this nice, mild cucumber flavor. This nice beige-yellow color. And so I love to grow that because I can't buy that anywhere. So gardening is also a lot about these personal preferences.  

And then the last thing, which is on the personal side of thing-- not necessarily in the plant-- is the end use, if you're going to grow one of those 50, 70 varieties of tomatoes, do you want to grow a slicing tomato? Do you want to grow something that you're going to can? Or if you think of cucumbers, the cucumbers that are really good for slicing in salads are different than the cucumbers that are really good for pickling. So you want to have this end use in mind. And once you go through all of those factors, that trims down the list of what you can grow pretty significantly.  

And what I like to do, personally, to decide once I've gone through all those maybe external constraints, is go to the Cornell gardening website, print out the recommended varieties list, and then go by crop. When I'm deciding, I can look at the seed catalog. So if you're in a store, it's really easy. Or whatever seed catalog supplier you pick, you can also have that sheet next to you. And you go, OK, I want to grow kale. The Cornell recommended variety list says these handful of kale varieties are good. This store has it in stock, so I'm going to buy it. And that's how I'd personally shop for my seeds.  

PAUL TREADWELL: Yeah the Vegetable Varieties for Gardeners guide is really useful in narrowing down the range of things. Even with that, when you look at a packet of seeds, you pick up a packet of seeds and you flip it over. And on the back, there can be this vast encyclopedia of information that-- I don't know if I'm atypical, but I don't have my growing zone memorized. And maybe people who are serious gardeners know this.  

But if you're just starting out in gardening, how do you start to make sense of things like growing zones and whether or not a seed is heirloom seed or an organic seed? Does it all come down to, I feel better growing organic, so I'm going to do that? Or how do you make sense of a seed package? [LAUGHS].  

STEPHEN STRESOW: Oh, no, that's a great question. Even as someone who studies this, it can be very confusing at the time. First off, I would start off with a lot of people, when they think of organic, they might think of non-GMO, GMOs. And for all your listeners out there, GMOs are not something you have to worry about in the context of gardening, because no company is going to make the investment to make a genetically engineered carrot or basil.  

PAUL TREADWELL: Oh, really?  

STEPHEN STRESOW: Right now in the United States, there's maybe about a dozen crops that are actually genetically modified that have been approved for market. So even if they don't have a USDA organic or certified non-GMO label on it, if you're buying out the garden center, it's not genetically engineered because nobody's made a genetically engineered version of that crop. So that's the confusion that a lot of people have that maybe us plant scientists haven't a good job of explaining to the public.  

And then to that next question, so why you might want to choose an organic-certified seed versus non-organic seed. And that really comes down to how that seed is produced. If a seed is certified organic, it's produced under organic conditions. So if you are going to be managing your garden organically without a lot of these herbicides or pesticides, or even it can be a small organic farmer or organic farmer having a certified-organic seed, it was bred and produced in conditions that might be more similar to what you're going to be doing in your garden as opposed to non-certified organic seeds. That's really what it comes down to.  

Another thing you can look for is seed producers in your area. There's a handful of new seed companies who are breeding seeds specifically for, say, New York's climate as opposed to Florida, Georgia, or California, just because we have differences. And then heirloom and open pollinated are the next two things that you might find on the seed packet.  

Every heirloom seed is open pollinated, but not necessarily every open-pollinated seed is heirloom. And what heirloom-- that's not a word that we hear a lot. So I think of it as heirloom is an old-timey word for old-timey varieties.  


STEPHEN STRESOW: It's varieties that maybe have been grown 100 years ago, 50 years ago. They stay around because they have one trait, one flavor, one component that's really unique. We hear a lot in tomatoes. Heirloom tomatoes tend to be delicious. But they don't look like what you see in the supermarket because the supermarket have been bred to be shipped across the country to store well-- to hold up in the refrigerator. So that's what heirloom means.  

And then open pollinated is that you can go in your backyard, and you can hand pollinate. You can wind pollinate. The bees can pollinate it. And you will get fruit from it. And that's different from what we also see is hybrids. So hybrids are completely natural. I think it's a term that confuses a lot of people. And all that a hybrid seed means is that you took two plants, and through natural plant selection processes you make a new variety. So say, parent one is really high-yielding. And then parent two is really disease resistant. So you cross those two plants, and then you get that F1 hybrid that-- knock on wood-- hopefully has the best traits of both.  

And so hybrids are great-- all natural. The only problem with-- in air quotes-- with hybrids is when you save seeds from hybrids, they won't come what's called "true to type." So you won't be getting the seeds from that plant you grew. You're going to be getting seeds that you have no idea what those genetics are going to look like. So if you're growing a hot pepper, and you want to have a hot pepper, maybe that hybrid that you save-- those spicy genes don't come out, or vice versa. You might be growing a sweet pepper, and then some spicy gene-- some hot pepper gene that's been dormant all these seasons-- pops up. So I would not recommend saving hybrid seeds.  

PAUL TREADWELL: OK, yeah. So if you're looking at seed saving, which is something I remember when I was growing up. I remember my grandfather would save his bean seeds and things like that. You could save hybrid seeds, but you're going to-- well, that's going to be a surprise garden then if you're saving hybrid seeds because you don't know what you're going to get next year, right?  

STEPHEN STRESOW: Correct. Correct-- surprise garden. Good surprises, bad surprises.  

PAUL TREADWELL: Yeah, I mean, depending on how fussy you are. I just want to go back to the organic seed thing for a quick second. Even if I buy all organic seeds, I can immediately make them non-organic by treating them with pesticides or things like that, right?  

STEPHEN STRESOW: Yes. So USDA organic is a very strict certification process to have something USDA-certified organic. So you can have that seal-- sell it by the seal-- that little logo that you see. There's all this paperwork. There's steps that you have to do. You have to transition your land from non-organic to organic. It's a robust national program to make sure that anything you buy that has that label meets the specific set of regulations.  

As a gardener who's growing stuff for home use or to share with your family, you can grow stuff organically-- use organic practices. But that seed that you sell, because you're not following the USDA national organic guidelines, you're not having an inspector come inspect your facilities. You can't sell it using that USDA logo. That doesn't mean that the crop that you're growing because it doesn't have that certification, which most people use to enter different markets to get a higher price for it, that there's anything wrong with that seed. It's just you're not paying for that label.  

PAUL TREADWELL: Right. So another thing on the back of seed packages that I know that I experience a lot is I will become very enthusiastic when this sort of weather starts happening. And I'll go and I'll buy a bunch of seeds. And they're all marked-- I'm buying seeds this year. They're for the planting season 2023. Do seeds expire? Do the seeds that I bought for this year-- can I not plant those next year? What is the downside?  

STEPHEN STRESOW: So it goes back to a conversation about surprises. So most seeds, you also might see on a seed packet-- it says germination percentage 90%, 95%-- really high numbers. And that means that 95% of those seeds in those packets are going to germinate. And that number holds true for about a year. And then every year after that, especially depending on how the seeds are stored, you're going to see a decline in those germination rates.  

So if you're a farmer-- you're growing stuff for production-- you definitely don't want to gamble. Are 10% of my seeds going to germinate? Are 70% of my seeds going to germinate? So that's why most people buy seeds year after year. Some of those seed packets will definitely survive two years, maybe three years. But it's really up to how much risk you're going to take. I know when COVID first hit, I'm back home. We're pulling seeds out of the garage. And some packets, everything germinates and it's fine. Other packets, absolutely nothing popped up.  

So waiting longer than a year for seeds that you've saved just introduces a lot more of that unknown variability. So it's 100% up to you as a gardener. Some tips first-- if you're going to store those seeds, you want to store them in a paper container because moisture and seeds, when you don't want them to germinate, is bad because then they could get moldy and just all die.  

A lot of people will store them in the refrigerator. And if you are like my parents-- and I have taken over the refrigerator to put in tulip bulbs and all these other non-immediately edible items-- and you can't store them in the fridge, just keep them in a dry cool place away from light. A cupboard or a pantry is pretty good for most people.  

PAUL TREADWELL: We have growing zones.  


PAUL TREADWELL: And I know, even in New York state, isn't there variation in the growing zones? Or am I misreading the maps?  

STEPHEN STRESOW: Oh, you are 100% correct. Yeah, growing zones in New York and in many states are very different. Long Island-- well, I guess, first I should explain to the audience that a growing zone is defined as the average minimum temperature. So a lower growing zone means that it's a lot colder from where you're from. And then a warmer growing zone is your average minimum temperature is a lot higher. So we have growing zones in Long Island is going to be very different from a place closer to the Adirondacks.  

And growing zones are really important if you're growing perennial species because that tells you if a perennial species like a tree or a blueberry bush is only suited for a particular growing zone. Then you don't want to grow a thing that's only hardy to zone 5 in zone 3 or zone 4 because come winter, it's just going to freeze and it's not going to make it unless you have a greenhouse or some plan to come up with that.  

But what's also really important, which a lot of people focus a lot in growing zones, is first frost date and last frost date. So your last frost date will be that time in April and May-- maybe even June-- that the risk of frost is still there. So we might even have some warm days in April.  

But if your last frost date is, say, May 15-- like it is in Ithaca-- you wouldn't want to plant something like tomatoes or eggplants that have no frost tolerance before that last frost date because even if you have a warm spell of weather, that risk of frost can come in and wipe out your garden. You might be able to plant kale, lettuce, some things that are a little bit frost tolerant.  

And shout out to Extension websites. For each county in New York you're in, your local Extension office will have a planting calendar. So it'll have different crops that you can plant come April or different plants you can plant in May. And they also have these things called last planting date, which means that's the last time you can plant that crop and get a reasonable harvest off of it because then the first frost of the year comes in. And maybe that first frost is first week of September. Maybe it's an unseasonably warm year when you get it to October.  

That goes back to something that is important when selecting seeds is knowing your growing zone-- knowing your first frost date, your last frost date. If you're up in the Adirondacks, you might not want to choose a variety that has 100-120 days to maturity. That might be great if you're in Long Island, somewhere that's a little bit warmer. But you could be running into either ends. You might not have a long enough growing season. So that days-to-maturity is one of those inherent seed characteristics that you might want to look out for, too.  

PAUL TREADWELL: If you take this seriously, you really need to sit down and map these things out, don't you, to effectively plant a garden that's going to give you the maximum satisfaction, I guess, is one way of saying it.  

STEPHEN STRESOW: Exactly. And that's why I recommend using those Extension resources and having those calendars because it's easier to look at them and say, don't plant these crops by this date. And you'll have a couple of days variation. Maybe last frost is earlier by a week, later by a week. But it gives you some guidelines that I find personally really helpful.  

PAUL TREADWELL: In looking at growing zones and first and last frost dates, I don't think I'm alone in noticing that we're starting to have some erratic behavior in our weather. How often are these growing zones updated and changed? Is climate change having an impact on our growing zone? Or is it have we not had enough time of this unsettled weather pattern to really factor it into how we plant our seeds?  

STEPHEN STRESOW: Yeah. So climate change is definitely affecting growing zones. But the thing you have to remember with growing zones is that it's an average-- of the average minimum temperature. So if we have one unseasonably warm year, that might be balanced out, quote unquote, by an "unseasonably cold year." So that average isn't changing. The last time the growing zones were updated was in 2012. So it's been about a decade. And that just goes because to update it annually for all those places in the country just doesn't make any sense, especially since you want to have a pretty long time to get those consistent, average datas.  

But yeah, we definitely see places are getting warmer, even if that's not reflected in a growing zone or last frost date/first frost date. But that's the thing with erratic weather and why it's important to still look at those historical averages of when your last-- when your first frost is-- because even a warm year might, all right, we haven't had a frost since mid-April. And this calendar says May 15. But to plant anything, you run into that risk that, historically, frosts have happened to that date. But I'm right up there with you. It is a lot warmer. I'm from Texas myself. And yes, those summers are very, very warm.  


PAUL TREADWELL: So how hard is it to save your seeds? So it's great to go out and buy exciting new varieties and try them out. But after a while, if I found things that I like-- if I found this particular hot pepper that grows really well and performs for me-- how hard is it for me to save those seeds from year to year?  

STEPHEN STRESOW: When you want to save seeds, you want to make sure that those seeds that you grow the next season are pretty identical to that plant with those traits. And so saving seeds is going to depend on a couple of things. One is that you're growing open-pollinated varieties. If you have any hybrids in there, do not save seeds. And then how many of a different crop you're growing.  

For example, say you're growing peppers. And you have your hot peppers and you have your sweet peppers. You want to make sure that no bee, butterfly, or wind is transferring pollen from one plant to another plant. And because it won't affect the fruit. If you don't want to save seeds, you can grow every single type of pepper in the world in your backyard. And that's not going to affect the fruit that you eat. The seeds that the genetic material. So that's what's going to make next year's crop.  

So what you want to do when you're saving seeds-- and this could be for tomatoes. This could to be for peppers. This can be for squash and pumpkins. You can buy these small mesh bags. Sometimes you see them for party favors thrown on the table with chocolates or sweethearts in them. And before the flower bud opens, cover it with this mesh bag. And what that mesh bag does is it will keep bees and other pollinators from cross-pollinating.  

And then what you can do is throughout the season, if it's a plant that has a what's called perfect flower, like tomatoes and peppers-- it has the male and female parts in it. You can just shake that flower in that bag, get a paintbrush, and make sure that plant is pollinated by itself or another plant of that same variety so that it keeps those genetic lines pure. If you're only growing, say, one tomato variety, and none of your neighbors have tomato varieties, and there's no chance that some random tomato plant pollen is going to come in, affect your tomato plants, you don't have to go through the trouble with all that bag.  

Or if you have a big yard-- big garden-- and you can put 500, 600, 800 feet between each pepper variety, then don't worry about those bags. So it really depends what you have in those gardens. We've done it in labs and classes. It's definitely a thing that's very feasible. You just have to be very careful about not letting any cross-pollination between different varieties occur.  

One thing I think it's great about saving seeds is people talk a lot about adapting seeds to your climate. But as the gardener, you're also part of that climate. So if you go on vacation in the summer-- and this past summer, we had a really dry season in New York-- and you have all your garden died except for a handful of plants. Those might be the plant that have that ability to adapt to drought that you want to save and keep growing.  

PAUL TREADWELL: So, Stephen, if I went on vacation for three weeks and it was a drought, and I came back and I noticed that these tomatoes and these peppers are doing really well, how late in the season would it be for me to bag the flowers and try to get a true seed from that variety?  

STEPHEN STRESOW: So as long as there are still unopened flower buds on that. So once the flower is opened, that's like Pandora's box. You have no idea what's happening. But if it was a closed flower bud that has yet to set fruit on it, that's something you can tie up and you can bag. Mid-summer, you might be OK. As we're getting later in the season, it becomes a little bit riskier.  

PAUL TREADWELL: Are many people doing that? Are many people out there actually saving their seeds?  

STEPHEN STRESOW: All across the country there's vast networks of seed savers. There's online organizations where you can trade seeds with people from all across the country. Even locally, there's individual gardeners who are saving seeds that are adapted for that specific region. I know some county Extension offices will host seed exchanges. Some library programs will have seeds that you can go-- instead of a book, you can check out seeds. And then you can go and save those seeds-- donate them back to the library.  

So you have these varieties that have really adapted to your local climate, which I think is just amazing. One of the great parts of gardening and seed saving is not just having these great crops-- these great genetics. It's that community that you build through saving seeds, sharing information, sharing stories, and the historical value of some of these crops and varieties that we might not know about.  

PAUL TREADWELL: You've worked with the Vegetable Varieties for Gardeners program here at Cornell. Can you talk a little bit about that? What is that program? Do people participate in that? Or are those things that are grown here at Cornell, and then Cornell recommends them?  

STEPHEN STRESOW: OK, awesome. So first, I'll answer what's selected in the brochure. So that comes from the Vegetable Varieties for Gardeners program, which I'll talk about in a little bit, as well as what some local farmers are growing. Say a professor used this variety in their research plots and performed really well. That might make it onto the list. But really, the purpose of the Vegetable Varieties for Gardeners is to crowdsource all this information from gardeners across the state who are growing these different varieties, and to rate them, and to get firsthand feedback on how they performed, and tips and tricks.  

So what the Vegetable Varieties for Gardeners is-- it's a website where not just anyone in the state, but anyone across the country could create an account and then enter the varieties that they're growing. And then you have the ability to rate them. So there's four different categories. One is overall. So you might get one to five stars. And then you have taste, yield, and ease of use. Some crops you might have to be pruning a lot. I think of tomatoes. You have to trellis them. You have to stake them.  

Or other crops you might have, and it's, I threw these seeds in my backyard, and this crop grew. I never watered it. I never did anything. And it did amazing. That's going to be a five-star yield. Versus my heirloom tomatoes were so delicate. I had to mulch. And I had to make sure there was good flow. And I had to-- they were riddled with pest and disease. Maybe five-star taste but definitely not five-star ease of use.  

And I personally like that because in addition to the recommended list, you have those stories. And that's awesome. And once you have an account, it's free to use. You can filter by state, by growing zone, by growing type. You can filter through all these crops. And that really helps see more detail than just what this recommended list has. And that's really fantastic.  

And another segue is that we use the Vegetable Varieties for Gardeners in combination with the Vegetable Varieties Trial Garden. The trial garden is that each master gardener organization in each of the counties across New York state has their different demonstration gardens. And in the past, they've just tried out different varieties-- ranked them. And we have this feedback, which is really great. But what we've been trying to do at Cornell Garden-Based Learning is reach more diverse audiences.  

New York state, I think, represents some of the best of what America tends to be. We have so many different cultures-- so many different communities in here. And a lot of mainstream garden publications and garden advice might not be targeting some of these crops in some of these communities. So what we've been trying to do is each summer the demonstration gardens have been focused around a a certain geography.  

So last summer was Latin America and the Caribbean. So we're growing and giving the master gardeners varieties that are really popular in those areas just to try and reach more diverse audiences. And that's what the great thing about the open-access forum that the Vegetable Varieties for Gardeners program is. It's that we don't know everything.  

So if you have a variety that's really important to you-- that you're really passionate about-- you can go at the website. And you can rank it. And then anyone who has access to the internet can see your reviews and a learn about these varieties. So even if you aren't officially associated with the Trial Garden program, not only can you see the results, you can try growing them next year and putting your own input. And I think it's a beautiful way to capture what people across the state are doing and inform decisions for other gardeners.  

PAUL TREADWELL: That's awesome. So the website is-- how do you get to the website?  

STEPHEN STRESOW: Let's see. I have my laptop out here. So I will run it for you. I just google Vegetable Varieties for Gardeners and then Cornell, and it comes up. But the actual website is  

PAUL TREADWELL: Using myself as an example, if I'm a lazy gardener, can I go to Vegetable Varieties and find, really, the easiest things for me to grow that are going to at least be nominally edible?  

STEPHEN STRESOW: Yes. That's the beauty of having all these different rankings of taste, yield, flavor, is if the most important thing to you is ease of use, you can rank it by ease of use. And then as you compare that, you could also see stuff that tastes good in addition to being-- weeds are really easy to grow, but that doesn't mean you don't want to eat every weed in your garden.  

PAUL TREADWELL: [LAUGHS]. That's awesome. So Stephen, I don't want to take too much of your time. Is there anything that we've failed to cover that we should have covered?  

STEPHEN STRESOW: One thing I will mention, when we focus on certain geographical regions, we'll post those varieties. So if you want to be part of it and grow as an individual, you can see varieties of child in years past. And you can also go visit your local Extension demonstration garden. I think that's one of the most important things about having this network of Extension. And also, check out all the Extension's resources and our website because there is a ton of good information.  

I think one last thing on selecting varieties-- I know there's a lot that come with selecting-- is the plant traits. One thing you might see is a lot of disease resistance. And on that sheet, I can tell listeners there's about 20 different diseases that some plants may or may not be resistant to. And that can be a very confusing thing. And so one, that's why we have the varieties that we recommended, so that if you don't want to think about that, just go with something that's recommended. It'll have good resistance to a variety of diseases.  

Two, if you always get powdery mildew in your area, then, yeah, have something that's resistant to powdery mildew. Resistant doesn't mean immune. The plants can still get sick. And you can kind of remedy that with good gardening practices, making sure you have good airflow, but making sure your plants aren't always dripping wet. That's a great place for bacteria and fungus to grow. Maybe using mulch to keep your soil from touching your leaves and your actual plant to reduce soil-borne diseases. There's a lot of things you can do to mitigate a variety that might not have good disease resistance. And that just goes all back to your personal preference-- personal skill.  

PAUL TREADWELL: One thing I realized we didn't talk about is soil. And we should probably mention soil because that's a primary thing that's involved in growing your garden here. How do you understand your soil? Is there a process that a gardener should go through to really understand the qualities and traits of their soil and how that's going to impact the seeds that they plant?  

STEPHEN STRESOW: Yes. So I think, visually feeling the soil, you can kind of tell it it's very sandy-- very clayey. There's some USDA maps that you can look at and tell you exactly your soil type. But one thing I really recommend to all gardeners is send your garden soil out for a soil test. They're not really expensive-- probably the $10 to $15 range. Contact your local Extension county to figure out exactly how to do that and who to send it to because that will tell you a lot of things, like soil pH.  

If you have very acidic soil versus if you have very basic soil, that is really going to affect nutrient availability, how well your crops are going to be able to perform, and also things like, if you have very clayey soil, maybe you don't want to grow carrots that get to a foot long. And you might want to grow some of those like shorter, couple-inch long carrots. And that goes back to the whole idea of variety selection. And depending on what's in your garden or what's in your backyard is going to determine what plants are most appropriate for your garden.  

Once you send off the soil test, it will tell you some really great results of nutrient availability. Maybe you probably-- do you want to amend with some compost and some organic matter? That always helps. You can't change your soil texture. If you have sandy soil, you're always going to have sandy soil. But you can do things to mitigate some of those challenges you might have. For example, sandy soil is really great in wet years because it doesn't stay waterlogged. In dry years, you're just gasping for moisture.  

So knowing the type of soil type you have can help you plan around it. Maybe you do want to use mulch. Maybe you don't want to use mulch. Adding organic matter-- not too much-- compost from a reputable source. Lots of people make home compost. And that's great. And that's awesome. If it hasn't heated up, there might still be some weed seeds that haven't been killed. And when I say for the heating kill-off, that's also a bigger concern of using animal manure.  

And I know this is going off topic, I just-- as food safety out there using raw manure on vegetables that you're going to be eating raw is something that can be done. But you should do it at least 90 to 120 days before you put those plants in the ground. So you don't run into any of those bacteria and getting sick. We don't want E. coli outbreaks.  

But yeah, the garden test will tell you a lot of what you need to know, especially on correcting nutrient deficiencies. And so you can come up with a fertility management plan and also figuring out the varieties you want to grow. Because if you have clay soil, and the seed packet says, does not do well in waterlogged soils, that's a red flag. You don't want to grow something there.  

PAUL TREADWELL: We've talked about a lot of different things. And it could potentially seem very complicated. Is gardening complicated?  

STEPHEN STRESOW: So I'm going to use a quote that one of my friends told me one time. I remember being so excited about gardening in my backyard compost. And he said, you know, you're just letting stuff grow. So on one hand, gardening is very complicated. And you can be very detailed. And you could have your calendar, and your plan, and your crop rotations. And you can make it as complex as you want to be. You could even, using myself as an example, decide to go pursue a PhD--  


STEPHEN STRESOW: --in vegetables and become very complicated. And on the flip side of things, it's as complicated as you want it to be. If you provide the soil with the right nutrients-- you provide water. You take care of your plants. You're following those guidelines. You're not popping stuff out in the middle of February just because we had one warm day. You will most likely yield something.  

My personal advice to gardeners is I like starting stuff off that's easy to grow-- kale, Swiss chard. They're not as finicky. You don't have to worry about trellising. And you get a lot of bang for your buck. It's something that you can use every day as opposed to tomatoes, which you might go through all these diseases. They get attacked by bugs. At the end of the season, you might have that $25 tomato.  


STEPHEN STRESOW: But gardening is fun. And it's all about the experience just as much as that final product.  

PAUL TREADWELL: Thanks, Stephen. I really appreciate your time and talking to us. We'll be sure to link to the Vegetable Varieties for Gardeners site as well as some of our local Extension resources so folks can find those easily. Really appreciate your time. And maybe we'll have you back in a couple of years to see what's new at that point.  

STEPHEN STRESOW: Awesome, Paul. Thank you so much. I really enjoyed being here. And happy gardening, everyone.  

PAUL TREADWELL: Thank you for listening to this episode. Extension Out Loud was produced and edited by Paul Treadwell. For more information about this episode, including show notes and the transcript, visit And be sure to subscribe to Extension Out Loud on your favorite podcast directory.  

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