How to Read a Seed Packet
Have you ever looked at a seed packet and thought it was written in a foreign language? It actually might be – some seed packages show the scientific name of the plant species in Latin! But even the parts that are written in English can be confusing if you’re just starting to garden. Plus every seed company seems to follow a different format with slightly different ways to say everything. Here’s the plain language explanation of the key information you need to know.
Plant Name
This information is pretty self explanatory, but for some varieties it can be a bit confusing. Usually the plant name is written in the largest font on the front of the seed packet. Sometimes over the photo, if there is one. But sometimes the plant type (like Carrot or Onion) is the biggest word and the variety is listed below. Some seed packets have the Latin name of the plant which usually includes the plant family and the variety. Unfortunately there are no standard rules for how companies print their seed packages, so you just have to figure each one out, or stick to buying seeds from a company whose printing format you like.
The plant name is key information for making sure you know which variety of seeds are in the packet. I have purchased the same variety of seeds from different companies and it can be hard to tell that they are actually the same if you’re just looking at the packets.
Where and When to Plant
Many seed packages will give you advice on if the seeds should be planted inside or outside and when you should plant them. But, of course, different companies use different terminology. Typically the package will say something like “Start indoors” or “Sow outdoors” and then provide a number of weeks before or after the last spring frost for your location. But sometimes they just say “as soon as the soil can be worked” for cold season plants where mud and frozen ground may be more of a problem than frost. Some seed packages will include a map with different zones that have different planting recommendations, or will refer to the USDA hardiness zones.
Where and when to plant is key information because sometimes you might need to start the seeds indoors months before your last spring frost. However, because the advice on the seed packages is generic for the whole country, you should treat it more like a guideline than a rule. Don’t be afraid to do your own research on what is right for your area.
How Deep to Plant
Whether you’re planting indoors or out, it’s key to plant your seeds at the right depth. A general rule of thumb is to plant a seed at a depth of two to four times its diameter. If you’re not ready to get out your tiny ruler, most seed packages have a recommendation as well. However, the wording can vary from “depth to sow” to “seed depth” to “planting depth”. Pretty much anything on the packet with the word “depth” in it is probably giving advice on how deep to plant the seeds, or how much soil to scatter over the top.
Planting depth is key information because planting too deep may cause your sprouts to struggle to get to the surface, but planting too shallow may prevent their roots from forming properly. Planting depth is particularly important for seeds planted directly outside because you won’t have a chance to reposition the plants during transplanting. Also, be careful watering after planting seeds that are close to the surface. The seeds can float up to the top. Luckily, I’ve found most seeds just really want to sprout and are pretty forgiving if you mess up.
How to Space Your Plants
Advice about how far apart to plant your seeds or transplant your seedlings can be really confusing on your seed packet. Some plants will give you advice for “seed spacing” but then tell you to “thin to” a different spacing. Basically the package is telling you to over-plant just in case you don’t get good germination and then pull out or pinch off some of the seedlings if too many sprout. In addition to “seed spacing” you may also get advice on “row spacing” or “rows apart”. If you’re going to plant in rows, this can give you some idea how much space the plants need. Like much of the advice on the seed packet, you should treat these spacing numbers as a guideline rather than a rule. If you are using an intensive planting method like square-foot gardening, you may choose not to follow the packet spacing.
Plant spacing is key information to help prevent overcrowding your plants. I hate killing off seedlings, but if you have too many plants too close together your plants can end up competing for nutrients or not getting good airflow which encourages disease. However, if you plant too far apart you can create opportunities for weeds to grow in between. Finding the spacing that works best for your garden could take some trial and error. Start with the recommendations on the seed packet and see what works for you.
How Long to Wait for Sprouts or Harvest
The last big category of information on most seed packets is days to germination and/or days to maturity. Not all seed packets will have this information and it sometimes depends on what kind of plant it is or how you harvest. If the seed packet lists “days to germinate”, that number gives advice on how long you might wait after planting to see sprouts. However, your growing conditions, especially if you are growing outside, can affect whether or not your seeds sprout in the given amount of time. Unseasonably cold or dry weather can increase the days to germinate. Then your “days to harvest” or “days to maturity” or just “maturity” or “X days” is typically the number of days after sprouting to when you can first harvest. Some varieties are marketed for quick maturity so they may have “X days” listed prominently on the front of the packet.
Days to germination is key information because some plants (like peppers) can take several weeks to sprout. Don’t give up on your sprouts and throw out your seed flats just because it takes longer to sprout than you expect. Days to maturity is key information to make sure your plants will get to harvest before your growing season is over for the year. Different varieties of the same kind of plant can have drastically different days to maturity. Make sure you are picking varieties that will work for your area. You can also use the days to maturity to figure out when to start second or third crops if you are going to succession plant.
Other Information
Some seed packets stick to just the basic information, but others have additional “growing tips” or “garden hints”. If you find the information on the packet about taking care of the plants, harvesting, or ways to prevent pests and disease useful, you might want to transfer it to your garden calendar or planner. My seed packets typically go back into the freezer for storage after I’m done planting, so I wouldn’t necessarily see that information throughout the growing season.
So, now you have a plain language guide to all the information you might find on a seed packet. Although most of it is useful advice, once you decipher it, you should generally treat it as a guideline rather than a hard-and-fast rule. Don’t be afraid to try some experiments and see how it works for you and your garden.
Need more help starting seeds? Get my free Super Seedlings Guide to get you on the right track.
Trying to decide where you should start your seeds? Check out Should I Start My Seeds Indoors or Out? for a quick look at the pros and cons of each option.
