How to Read a Seed Packet (So You Actually Use What's On It)

How to Read a Seed Packet (So You Actually Use What's On It)
Seed packets pack a surprising amount of information into a small piece of paper, but if you've never grown from seed before, all those numbers, symbols, and abbreviations can look more like a puzzle than a planting guide. The good news is that once you know what you're looking at, a seed packet becomes one of the most useful tools in your entire garden — a mini instruction manual written specifically for the seeds inside it.
Before you start sowing anything, whether directly in the garden or indoors under lights, here's how to actually read and use everything on that packet.
Why the Seed Packet Matters More Than You'd Think
It's tempting to treat the seed packet as packaging and toss it aside once you've opened it. But that packet often holds the single most reliable, variety-specific guidance you'll get — more precise than general advice, because it's written for that exact seed. Two varieties of the same vegetable can have very different needs, from days to maturity to spacing to sun requirements, and the packet is where those specifics live.
Hang onto it (or jot down the details somewhere) until your plants are established, since you'll likely reference it more than once.
The Front of the Packet
The front usually gives you the basics at a glance:
Plant name and variety: Not just "tomato," but the specific variety, like "Cherokee Purple" or "Sun Gold." Varieties matter — they can differ in size, flavor, disease resistance, and growing needs.
A photo or illustration: Helpful for knowing what you're aiming for, though keep in mind real results can vary based on your growing conditions.
Days to maturity: How many days from planting (or transplanting, depending on the packet) until you can expect to harvest. This helps you plan your season and confirm there's enough time before your first fall frost.
Planting Information
This is the section you'll refer to most, and it typically includes:
Planting depth: How deep to sow the seed. A common rule of thumb is to plant a seed about twice as deep as its width, but this varies, so always check rather than guessing.
Spacing: Both between individual plants and between rows. Crowding plants too closely is one of the most common beginner mistakes, so pay close attention here.
Sun requirements: Usually shown as full sun, partial sun, or shade, sometimes with a sun symbol. Full sun typically means at least 6 hours of direct light per day.
Soil temperature: Some packets specify an ideal soil temperature range for germination, which matters more than air temperature for many seeds.
When to plant: Often given relative to your last frost date, such as "sow directly after the last frost" or "start indoors 6–8 weeks before last frost."
Direct Sow vs. Start Indoors
Many packets will explicitly recommend one method over the other, or note that both are possible. Some plants, like carrots and beans, dislike having their roots disturbed and generally do better sown directly in the garden. Others, especially slow-growing or heat-loving crops like tomatoes and peppers, benefit from an indoor head start. If the packet doesn't specify, this is worth a quick search for that particular plant, since getting this step right has a real impact on success.
Germination Information
Somewhere on the packet, you'll usually find:
Days to germination: How long it typically takes for the seed to sprout after planting. This helps you know whether to be patient or whether something's gone wrong.
Germination rate: Some packets note the expected percentage of seeds that will successfully sprout, which is why it's common practice to plant a couple of seeds per spot rather than just one.
Understanding the "Days to Maturity" Number
This number deserves special attention because it's easy to misread. For crops you start indoors and then transplant, days to maturity is often counted from the transplant date, not the original seed-starting date. For crops that are direct sown, it's usually counted from the day the seed goes into the ground. When in doubt, this is a good detail to double-check on the seed company's website, since it affects how you plan your season.
Packed For [Year] and Other Fine Print
Seed packets are typically labeled with the year they were packed for, which matters because germination rates decline over time. Seeds don't necessarily become unusable the year after, but older seeds may germinate less reliably, so it's worth planting a few extra if you're using seeds from a couple years back.
You may also see:
Lot number: Mainly useful for the seed company's tracking, not something you need to worry about.
Special symbols: Such as organic certification, heirloom status, or open-pollinated vs. hybrid labeling. Hybrid (F1) seeds won't reliably produce the same plant if you save and replant their seeds the following year, while open-pollinated and heirloom varieties generally will.
The Back of the Packet
The back typically expands on the front with fuller instructions, and often includes:
Step-by-step planting instructions
Thinning guidance: Once seedlings emerge, how far apart to thin them if multiple came up close together
Care instructions: Watering and fertilizing basics specific to that plant
Harvest tips: Signs the plant is ready to pick, and sometimes how to encourage continued production
Putting It All Together
Before you plant, take a minute to actually read through the packet front to back rather than skimming for the planting depth and calling it done. Understanding the full picture — sun needs, spacing, direct sow versus indoor start, and days to maturity — means you're setting the seed up for success from the very first step, rather than troubleshooting problems later that a quick read could have prevented.
Once you've read the packet and know what a seed needs, the next step is deciding whether to sow it directly in the garden or give it a head start indoors — something we'll walk through in the next post.