How to Read & Understand Seed Packets
Seed packets can contain a lot of confusing information, but learning how to read seed packets is crucial when it comes to giving your plants the best start in life. Here’s a breakdown of all the information included on most seed packets, and how to actually understand it all.
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As I write this, it’s the first week of March, which means spring gardening season is just beginning for most of us here in the northern hemisphere.
That also means it’s seed-starting season!
But before you just start throwing seeds in the ground or into red solo cups on your windowsill, it’s important to take some time to read your seed packets and get to know each crop’s specific needs.
Understanding the information on a seed packet is super important when it comes to gardening, especially if you want your plants to get a strong, healthy start and produce an abundance of food for you. And what gardener doesn’t want that?!
The risks of NOT reading your seed packets…
If you’re a newer gardener or you’ve never actually learned how to read a seed packet before, some of the information can feel a bit confusing and even overwhelming. I remember the first time my husband and I made a pitiful attempt at starting carrot seeds one spring…
We were still living in our city condo, and decided we weren’t going to wait to move out of the city to start our garden. We were going to start it right there, on our shady, north facing balcony, where we couldn’t even keep herbs alive!
(I’m living proof that anyone can learn to garden and grow food, because I clearly had NO IDEA what I was doing at first!)
For starters, I don’t think we even really knew that we had to read a seed packet. We just sort of assumed that you started seeds in the spring. We also didn’t know that you’re supposed to direct sow carrots seeds and not start them indoors. Had we read the seed packet, we probably wouldn’t have made that mistake!
Oh, and we put them on a dresser that was sort of near a sunny-ish window, but not nearly close enough. Our little seedlings we reaching desperately for the sunlight while we flooded them with water and, eventually, drowned them.
Now, I’m not saying that learning how to read and understand a seed packet would have helped us to avoid all of those mistakes, but it would have helped.
Set yourself up for success
I’ve spoken to many first-time gardeners who’ve done similar things with their seeds and then wondered what went wrong— why their seeds didn’t germinate, why their seedlings died or didn’t make it when they transplanted them into the garden, or why they barely produced any food in the end. Very often I find that many of the mistakes that led to these outcomes could have been avoided if they’d only read and followed the directions on their seed packets first.
Because believe it or not, there’s actually a lot of useful information on there!
It’s a little like reading a full recipe before you start to cook, or reading the instructions before you put a piece of IKEA furniture together: if you don’t take the time up front to read through thoroughly, you could find yourself missing ingredients halfway through a recipe, or with a bunch of extra hardware wondering where on Earth you went wrong!
The point is, if you really want to set yourself up for success in the garden, take some time to read and understand your seed packets before planting!
How to read seed packets
Now that you know why it’s important to read seed packets, here’s how to actually read them…
What information is on a seed packet?
Most seed packets include a lot of information about the seeds and the plants they will one day become. While not all seed packets are created equal, most seed packets include the following information:
- Plant type and variety
- Seed type (open-pollinated/heirloom or hybrid)
- Days to maturity/harvest
- When and where to start seeds
- Packaging date
- Number of seeds
- Seed depth and spacing
Every seed packet is different and includes slightly different information, although in general most seed packets available commercially will include the information listed above.
Other information that is sometimes (but not always) included:
- Germination rate
- Days to germination
- Optimal soil conditions & temperature
- Seed/plant descriptions and specifics
Let’s unpack each of these things one-by-one…
Plant type and variety
The single most important piece of information on a seed packet is the plant type and variety. Obviously this is important because without it you’d have no idea what you were planting! Usually this can be found right on the front of the seed packet— for example, it might say “Lettuce/Romaine,” or “Tomatoes/San Marzano.”
This sounds like an obvious piece of information to check, but it does matter, because certain types of plant varieties are better suited for different needs.
For example, San Marzano tomatoes are best for making tomato sauce, while a variety like Brandywine is best for fresh eating. Other varieties do well in containers while some do much better in the ground.
Decide what you want to get out of your garden and then choose seed types and varieties that will best suit your specific needs.
*Another reason why knowing the specific plant type and variety is important is because even if there’s little other information included on the seed packet, you can easily Google the plant type and variety and find all sorts of information about planting and growing that particular crop.
Most seed packets will also tell you what type of seeds are inside. The seed type is not the same as the plant type. Rather, seed type refers to whether the seeds are open-pollinated or hybrid seeds. This could also refer to whether or not the seeds are heirloom seeds, or even genetically modified seeds.
Open-Pollinated Seeds (OP)
Often referred to as “OP” on seed packets, open-pollinated seeds are seeds that are pollinated naturally— by wind, by insects, or even by self-pollination.
Open-pollinated seeds are sort of like the purebreds of the plant world, that will grow true to whatever parent plant they came from. Therefore, if you want to be able to save seeds from your plants at the end of the season, you’ll want to plant open pollinated seeds. You can learn more about saving seeds here.
Hybrid Seeds (F1)
Hybrid seeds are often referred to as “F1” on a seed packet. This stands for “Filial 1” or “first children.” In other words, they are the first generation of a hybrid seed that was pollinated by crossing one variety of plant with another. They’re basically cross-breeds that are deliberately bred by hand to create an offspring that has desirable qualities from both parents. However, they are definitely not genetically modified or created in a lab.
Hybrid seeds are perfectly healthy and organic (as long as their parents were raised organically and they haven’t been treated with anything), and are comparable in taste and nutrition to open pollinated and heirloom plants. So don’t ever worry about growing hybrid seeds! However, if you want to save seeds from your plants, you’ll want to avoid hybrid seeds because often when you save and replant seeds from hybrid plants, they won’t grow true. Instead they may revert back to one of their parents or will end up with a mix of strange (unintentional) traits.
Basically, you don’t really know what you’re going to get in the end when you plant seeds from hybrid plants, so you’ll need to re-purchase them each year.
Ah, heirloom seeds… These are the seeds that every gardener tends to covet; the ones that gets put on a pedestal above all the other seeds. But heirloom seeds aren’t always necessarily the best.
Heirloom seeds are simply open-pollinated seeds that have been selected, saved, and replanted for a number of decades or generations. So they’re naturally pollinated seeds (unlike hybrids), but they’re seeds that have been selected from the healthiest plants with the most desirable traits for long enough that they’ve often developed special qualities like superior taste, high yields, large fruits or unique colouring and visual characteristics.
Basically, all heirloom seeds are open-pollinated seeds, but not all open-pollinated seeds are heirloom seeds.
There is no exact number of years that a certain seed strain needs to be saved for to be considered an heirloom, although it’s generally agreed upon that it should be at least 50 years old (or about three generations) in order to qualify as an heirloom strain. Some people say it should be at least 100 years old. But at the end of the day you could create your own heirloom strain from any open-pollinated seed variety; you’ll just need to save it for 50 years and hand it down through a few generations first;)
Seed packets do not always specify if the seeds are heirloom seeds. Some will, but others will just say “OP,” so if growing heirloom seeds is important to you, you might have to do a little research on heirloom varieties first.
You can learn more about the best heirloom seeds and about growing an heirloom vegetable garden here.
Genetically Modified Seeds (GMO)
Genetically modified seeds (GMOs) are definitely seeds that you want to stay away from for many reasons, but the good news is that GMOs just aren’t available to home gardeners. They’re made (in a lab) for large, commercial, monoculture farms, and while some GMO seeds can cross-pollinate with plants in your garden if you’re too close to a farm that grows GMO crops, you don’t have to worry about accidentally buying genetically modified seeds.
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Days to maturity / Days to harvest
Most seed packets will also tell you the “days to maturity” or “days to harvest.” This is the number of days a plant will take to produce a harvest from the time of planting out in your garden.
This is important information to know depending on your climate, because if you live somewhere colder with a short growing season, you’re going to want to choose seeds that will grow and produce a harvest before you get your first frost.
Likewise, if you’re late on planting, the “days to harvest” will help you to know if you can still plant something and expect to get a harvest before the season ends.
One thing to note is that you start counting the “days to harvest” at different times, depending on what you’re growing. For seeds that are direct sown in the garden, you can start counting the days to harvest as soon as the seeds germinate and emerge from the soil. (Some people say to wait until the seedling has its first true leaves before beginning the countdown).
If, however, you have started seeds indoors or have purchased seedlings from a nursery, you’ll start counting the days to maturity/harvest once you’ve transplanted them into your garden.
When and where to start seeds
While the “days to harvest” will give you a good general idea how long it will take for your plants to produce a harvest, most seed packets will do the math for you and will tell you when and where to plant your seeds in the spring.
For example, a seed packet might tell you to “start indoors 6 to 8 weeks before planting out.” This means you would start your seeds indoors roughly 6 to 8 weeks before you’re ready to transplant the seedlings out into your garden. Many seed packets will state more explicitly when you should transplant seedlings to your garden, as some crops can go outside in early to mid-spring (like lettuce and onions), while others need to wait until the weather warms up more (like tomatoes and peppers).
If the seed packet says to “direct sow outdoors once all danger of frost has passed,” then you would wait until after your last frost date and plant the seeds directly in your garden.
Knowing when your first and last frost dates are is definitely helpful as a gardener. You can find your average frost dates here.
Seed packets typically include a packaging date, which is simply the year they were packaged for— so if you buy a new seed packet, it will most likely say that it was packaged the same year that you bought it. But if you end up gardening for any length of time, you will inevitably end up with leftover seeds from years past.
The packaging date is super helpful because the older seeds are, the lower their germination rate tends to be. You’ll want to make sure you use up older seeds first in order to get the most out of them. So if you plant a packet of seeds with a packaging date of 2015 and none of them grow, you’ll know it was most likely because they were too old and were no longer viable.
Number of seeds
Most seed packets should also tell you the number of seeds in each packet. This is useful to know and pay attention to so that you can ensure you have enough of certain crops to fulfill your needs, and roughly how many seasons the seed packet should last you. It helps you to avoid overbuying, too.
For example, when we start our tomatoes indoors, the seed packets we get typically come with about 30 seeds. We grow around 30 plants each year, so one packet of seeds per year is enough. Our packet of broccoli seeds, on the other hand, contains upwards of 300 seeds! We grow about 12 to 16 plants per year, so one packet will last many years so long as the seeds remain viable.
Onions are another example that comes to mind. This year, I planted a different variety of storage onion and just assumed we’d get around the same yield as last year when we planted a different variety. But when I planted all the seeds, I discovered there were only about 50 seeds in the pack compared to the 200 seeds we started last year. I didn’t manage to get more onion seeds in time this year, so we’ll be growing fewer onions than I had hope this season.
(See… I still make rookie mistakes too!)
Seed depth and spacing
Seed packets will also usually tell you how deep to plant the seeds and how far to space them apart when direct sowing or transplanting outdoors.
The general rule of thumb is to plant seeds twice as deep as they are large. So for tiny seeds like broccoli seeds and lettuce seeds, you only need to plant them about ¼-inch deep. But for larger seeds like peas and beans, you’ll need to plant them about one to two inches deep.
As for spacing, most seed packets will tell you how far apart to plant each seed, or how to space each plant so that they have room to grow and stretch their roots. Sometimes it will also tell you how far apart to space your rows so that you have room to walk between them, but this is only important for market-style gardens that are planted in rows.
It might also say to plant and thin seedlings to a certain distance apart. In this case (like with carrots), it’s easiest to plant a bunch of seeds in rows and then thin (aka. pull out) extra seedlings as they emerge in order to give the ones that remain enough room to grow big and produce lots of food for you!
The germination rate is the average percentage of seeds that you can expect to actually germinate and grow. There are almost always at least a few duds in every seed packet, and some varieties tend to have a slightly lower germination rate than others (aka. more duds). Knowing the germination rate ahead of time can give you a better idea of what to expect in terms of how many seeds to start and how many plants you’re likely to end up with.
Remember too that older seeds tend to have lower germination rates, so if a seed packet says “92% germination rate” but the seed packet is three years old, that number might be closer to 80-85%.
Days to germination
Along with the germination rate, your seed packet might include the “days to germination,” which is the average number of days it takes for certain seeds to germinate and start to grow.
This can be especially useful to know when you’re waiting for what seems like FOREVER for your seedlings to emerge from the soil —ahem… I’m looking at you sweet peppers!— because you can refer to the seed packet and see whether it’s normal for the seeds to take that long to germinate or whether you’ve got yourself some duds and should do another planting of newer, more viable seeds.
Light and/or sun
Many seed packets will also tell you how much light or sun your plants will need as they begin to grow. Your seed packet might say “full sun” or “direct sun,” “partial sun,” “partial shade” or “full shade.”
Usually if a seed packet doesn’t indicate how much sun your plants will need, you’re probably safe to assume “full sun,” as most plants (annual vegetables in particular) do best in full sun.
Optimal soil conditions
Your seed packet may also tell you what soil temperature and conditions are best for the seeds. Some seeds like peas and radishes can be planted when the soil is still fairly cold— as soon as the soil can be worked in the spring. Other crops like cucumber, squash and melons need warmer soil to germinate and grow. Some crops do better in sandier soils and others need more humus-rich soil, etc.
You’ll probably have a pretty good idea of what soil temperature is best based on the information on when and where to start your seeds, and as far as soil composition, you can really never go wrong with adding compost and organic matter to any type of soil.
Seed descriptions and specifics
Aside from all of the above, some seed are just very unique and require special planting instructions or warrant a special description, so look for additional information on your seed packets that can help you get the most out of your plants.
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What if your seed packet is blank?
If you save your own seeds, participate in any type of seed exchange, or are gifted seeds from a friend or neighbour, you may end up with homemade seed packets or envelopes with no information on them at all. If this is the case, you’ll have to do some digging online (or in books if you’re old school), but you will at least need to know the seed type and variety first.
Always make sure to write this information down when saving seeds so you don’t forget! And if you do have the original seed packets, I make a point of holding onto mine throughout the growing season and sometimes even longer so I have them to refer back to whenever I need them.
At the end of the day, you could ignore basically everything on a seed packet and just throw some seeds in the ground and hope for the best, but you’ll likely have a lot of things fail before you ever get a harvest. So do the work up front and read your seed packets before planting! You’ll save yourself a lot of wasted time and effort in the end.
And just know that the longer you garden for, the more second-nature it will become and the less you’ll have to look at the seed packets. Sort of like cooking without a recipe, or putting together IKEA furniture without the instructions;)
(Although, is there seriously anyone out there who can put a piece of IKEA furniture together using ALL of the parts without the instructions? Doubtful. Very doubtful.)
>> For more help with seed-starting, sign up for my FREE Resource Library to get my Seed-Starting Cheat Sheet (and so much more!) You can find the cheat sheet under the Gardening Resources section of my resource library:)
Wishing you homemade, homegrown, homestead happiness:)
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