How to Read Seed Packets

Do you read seed packets? I mean really read them, not just the name of the variety you want to grow. Be honest!

I don’t think I really did when I first started gardening – maybe the description, but that was it. Mainly, it was because I wasn’t sure what everything meant.

So let’s talk about it, because those seed packets are surprisingly full of helpful information.

Front of Seed PacketsHere are some descriptions, in layman’s terms, of what is usually included on a seed packet. Typically, seed companies put the most important information on the back of the seed packet, so we are going to start there.

Reading the Back Of A Seed Packet

Different seed companies use different terms, so I tried to include as many as possible, along with the a definition or explanation – in plain English.

Back of Swiss Chard Seed Packet

Days to Emerge/Days to Germination/Germination: This is how long you can expect before you will see the sprout start to rise up from the soil level. Carrots are a great example of where this can be helpful. They can take up to 21 days to germinate, which will help you know that you don’t need to plant more if you don’t see them sprout after two weeks. You will know they are coming soon.

Seed Depth/Seed Planting Depth/Sowing Depth: This is how far down you need to push or bury the seed when planting it. It usually varies from ⅛” to 2” and is important because you want strong, stable roots for your plants. Planting them at the correct depth in the soil will help ensure that.

Seed Spacing: This tells you how far apart to space your seeds from one another when planting. The space is determined by how much room a plant needs for its roots underground or to spread out above ground. Additionally, it needs room to soak up water and nutrients without competing with other nearby plants. In order to have the most productive plants, pay close attention to the spacing.

Plant Spacing After Thinning/Final Plant Spacing/Plant Space: Plants need space, some more than others. Thinning allows the plants to have the space they need. A common error of a beginner gardener is to plant seeds too close to one another. This often times leads to diseases like powdery mildew, so be sure to space them according to the packet’s directions. *see thinning for more information

Row Spacing/Final Row Spacing: Generally, row spacing is the space needed between rows to allow room for people or farm equipment to get through. Personally, as a backyard gardener, I always ignore this number. If you plant in rows, use this as a guideline for the space between each.

Thinning: Thinning refers to when you remove some of the sprouts that germinated, leaving the most successful (tallest, sturdiest, strongest) plants to mature. Thinning ensures that plants have the space they need even if they sprouted too close to one another.

Plant Height: This informs you approximately how tall the plant will be when fully grown. This is helpful for when you initially plan out your garden. For instance, you might want taller plants in the back and shorter plants up front to make it more visually appealing or to ensure that all of your plants get enough sunlight.

Less Common on Back Of Seed Packets

Back of Multiple Seed Packets

Light: Tells how much sunlight the plant needs. This information is commonly on the front of the packet as well. Be cautious with this, and make sure you know your area. The seed packets are distributed all over the USA, or sometimes internationally. Full sun, however, is very different in Texas than in Ohio. Check your local agriculture extension office for tips, if needed.

Soil Temp: This tells you the ideal temperature for the seeds to germinate.

Direct Sowing/When to Start Outside/Start Outdoors: This tells you when to plant directly into the ground. It typically tells you when to plant based on your average first or last frost date (e.g. 2 to 4 weeks before average last frost for late summer harvest). You can find the average first and last frost dates for your area here by clicking on the Frost Calculator.

Transplanting/When to Start Inside/Plant Indoors: This tells you when to start seeds indoors if you are planning to start the seeds in growing trays inside and then move them outside once they reach a certain size/maturity. Again, this is typically based on your average first or last frost date which you can find out here.

Culture: So far, I’ve only seen this section on Southern Exposure Seed Exchange seed packets, and it is full of information on how and when to sow the seeds, the soil pH needed, how to water, and advice on applying mulch.

Harvest: This tells you how many days until you can harvest and eat the edible parts of your plant! It often warns you to harvest before high heat or the first freeze, if applicable.

Germination Temp.: This is the temperature required for the seed to germinate. If you can, start seeds inside to extend your growing seasons and control the temperature a bit more. Otherwise, wait until the outside temperature is right for germination before planting.

Seed Savers: This is information for those wanting to save seeds from the plant in order to have more seeds to give away or plant in the future. Chances are, you won’t use all of the seeds in one packet in the first season, but this could be useful to know later on. If you aren’t at this point yet but know you will be in the future, ignore it for now and hang on to the seed packet until you need the information.

Tips: Oftentimes, this section will include whether or not it is helpful to soak the seeds overnight before planting. Beans, peas and corn are all examples of crops that do well when the seeds are soaked overnight. Check the seed packet to see if this is true for the variety you purchased.

Front of Seed PacketCarrot and Swiss Chard Seed Packets

Name/Variety/Cultivar: The front of most seed packets will have the name of the plant and the variety or cultivar. This is important if you are looking for a specific variety that is disease resistant, cold hardy or bolt resistant. If you don’t have anything specific in mind, read the description to see if it matches your goals/desires.

Description: A brief description of the variety or cultivar. This may include the date and area from which the plant originated, as well as what makes it special or unique.

Percentage – %: This tells you the percentage of seeds within the seed packet that are likely to germinate. There is a chance that not all seeds will. For example, my Arkansas Traveler tomatoes from Southern Exposure Seed Exchange have an 82% germination rate, so they don’t expect every seed to sprout.

Cool or Warm Season: Warm season plants are grown in the summer, while cool season plants are grown in both the spring and fall in most climates. This articles goes into more detail and provides examples of each.

_ days from transplanting/ _ days to maturity/ _ days: This tells you how long until you will be able to harvest the edible parts of the plant.

Open pollinated/Hybrid/Heirloom: This is most important if you plan to save seeds, but is definitely good to know as a gardener regardless. This articles explains the difference between all three extremely well.

Light: Again, this tells if the plant needs full sun or light shade. Be cautious with this and make sure you know your area. The seed packets are labeled and then distributed all over the USA. Full sun, however, is very different in Texas than it is in Ohio.

Perennial/Annual: Perennials grow for more than two years while annuals only grow one year. Annuals are seeds you will need to replant unless you let them drop seed and they come back on their own the following season. Perennials do not need to be replanted. At times, it’s best to buy perennials as transplants because you might not use all the seeds. Here’s an article to help you determine when it’s best to buy seeds and when it’s best to buy transplants at a local garden store.

Similar to the intensity of light being dependent on your latitude, some plants may be a perennial in one area and an annual in another. Knowing your plant hardiness zone will help you identify whether a plant is an annual or perennial for your area. 

Lot #, Weight, Cost: Additionally, several have the lot number and weight in milligrams, grams or ounces, which is mainly to help them with shipping and inventory. Occasionally the cost also appears on the front of the seed packet.

Seeds of Change and Seed Savers Exchange

I have purchased seeds from Seeds of Change many times and recommend them here. Their seed packets are a bit unique, but more so in the visual presentation than the information included. For example, amount of sun is not written on the packet, but there is a picture of a sun, and if full sun is best it will say “full” underneath the image.

Front of Dark Star Zucchini Seed Packet

The Zone Map is the only big difference, which is helpful if you live in the USA. Head here to find out your specific plant hardiness zone.

The images and information are all pretty self-explanatory but might look intimidating at first, simply because it looks different than other packets. Once you know the information above, you can apply it here. Back of Dark Star Zucchini Seed Packet

Seed Savers Exchange is another seed company that I have seen use images. Again, you can apply the information above to help you translate their seed packets.

I wasn’t kidding when I said the packets are chock-full of information! I hope this helps you experience more gardening success. If you ever end up with a packet that is lacking information you need to know, the seed company most likely has it on their website, so head there first. Here’s a list of my favorite seed companies.

1 thought on “How to Read Seed Packets”

  1. Camille Devaux

    I really like that you mentioned the importance of getting weight costs. Looking into the importance of checking the weight in milligrams is a great idea. My sister might like knowing this as she looks into seed packets.

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