How to read and understand a seed packet

I've been gardening for many years and I still get stumped sometimes when reading seed packets! There is so much information fit onto those tiny little packets, and it ALL matters! To add to the confusion, all seed packets don't have the same information!

It's seriously annoying because sometimes they have all the info you could possibly want, and other times it's like 3 things! *sigh*

Today I want to talk about the different type of information you'll see on the back of a seed packet, what it means and how to use it. From deciphering sun exposure requirements to mastering spacing recommendations, lets go through what everything means!

How to read the back of a seed packet

You're going to have to read tags or seed packages when choosing the different seeds to buy, as each one can have a different time frame. If you're new to home gardening, the word varieties simply means the group of plants within a species that has one or more distinguishing characteristics.

While looking for a type of tomato or carrot, one might be looking for a variety that has a certain texture, flavor or grow time. In this case, you'll be looking at grow time when selecting your seeds.

For instance Early Girl tomatoes only take about 50 days for the first fruits to be ready. Brandywine tomatoes take 90 days. That leaves a large margin for error if you just grab a packet of tomato seeds without reading it! This is important because if you live up north with a short growing season, you'll need a variety that will be ready before the weather turns too cold

Related reading: The 7 worst seed starting mistakes I've made!

Seed Packet 101: A Beginner's Guide to Reading Planting Directions,

I've outlined the areas you are looking for on the picture below. I used several packets of pea seeds for this image so you can see how the info can differ among the same type of plant.

You can click this picture to make it bigger!

Days till harvest 

Outlined in red. This is how many days it takes for this plant to be able to harvest the first vegetables. In this case some of these peas will be ready at 55 days while others take 70 days. You'll want to choose based on how long of a growing season you have and whether you start seeds indoors or not.

Seed pack date

Black and white & arrow. Sometimes this says packed for the 2024 season, other times it says plant by or sell by 2024. Or whatever year you're working with. (I took this picture in 2020!)

You can plant expired seeds. However you will get a better germination rate from fresher seeds. If you are buying them now they should have this year on them. If you are using seeds that are a few years old you'll want to plant a few extras just in case they don't all grow.

Days till germination 

Outlined in white. This is the time it takes till you can see your seedlings emerging. As you can see it's often listed on the chart, but some seed packets bury this information in the growing instructions.

Unfortunately almost no seed packets explain watering directions which is kinda silly since water is needed for germination! As a general rule, most seeds need kept moist but not wet until they germinate.

Growing instructions

Outlined in purple. This usually includes how much sun a crop needs, watering instructions if their included and some have info on harvest.

Planting depth

This is often included in growing instructions and is super important because planting too shallow or too deeply can mean nothing sprouts! Planting depth refers to how deep the seeds should be buried in the soil to ensure they can get the proper amount of moisture, oxygen, and nutrients.

Each type of seed has its specific planting depth requirements, so it's crucial to read the planting directions on the seed packet carefully.

Planting map 

Outlined in burgundy. This little map shows you when it's generally safe to direct sow the seeds into the garden. If you don't want to mess with seed starting indoors, these are the dates you can plant in the ground. This is also when you can move your seedlings out to the garden.

Not on all packets (but they should be!)

Spacing Recommendations

Spacing recommendations tell you how far apart to plant your seeds and are super important because if you plant things too close together, they will not grow properly. For instance radishes only need a few inches in between them but broccoli is going to need at least a foot, maybe 2!

The spacing recommendations listed on the seed packet will give you a distance for planting based on the ideal amount of space needed around the plants for growth, sunlight exposure, root development and airflow. This information helps you when arranging your seeds to allow for proper air circulation.

Sun Exposure Requirements

The amount of sun exposure a plant gets is crucial for proper growth. Different plants have varying preferences when it comes to sunlight. Some plants thrive in full, direct sun, while others prefer partial shade. Checking out the sun exposure requirements listed on seed packets will help you choose the right spot in your garden for each plant

If you made a sun map of your garden, you'll know how the sun moves over the garden and which areas get full sun and which ones get some shade. If you haven't done it yet, you'll want to make a sun map of your garden before planning your garden just to help get everything in the right place.

What does soil temp mean?

Soil temperature is exactly what it sounds like and it plays a crucial role in successful germination. Some seeds need warmer temps to germinate, it's why people use a warmth mat for seed starting! By knowing and testing your soil temp before planting you'll know if it's warm enough for the seeds to germinate. 

You can check soil temperature by using a soil thermometer, which is stuck into the soil to get an accurate reading.

Sometimes the seed packet says ideal temp, but that's sort of the same thing. Often the ideal temp is not reached by the last frost date for your region, so waiting to start seeds in the ground can put your plants behind several weeks. 

If you start them indoors 4-8 weeks before the estimated last frost date, you'll need a heated seed mat but you'll be able to harvest 1-2 months earlier!

Related reading: Determining your planting zone and last frost date.

What does frost hardy mean?

When seeds are labeled as frost-hardy, it means that they can tolerate exposure to frost without being damaged. This is particularly important in regions with unpredictable weather patterns or in the early spring when frost is still a possibility.

Frost hardy seeds have the resilience to endure colder temperatures, giving them a better chance of survival in adverse conditions. So you don't have to worry as much about that estimated last frost date.

Make sure to read everything on the seed packet when choosing seeds. They often describe what exactly makes each variety unique and any specific instructions for growing. Some seeds state whether they are an annual or perennial. Some have information on where to plant them, like if they are suitable for containers.

There's lots of information they could include, and I've bought a frustratingly large amount of seeds with hardly no information at all! Sadly, it's sort of a look and see situation!

Related reading: Impatient for your food crops to be ready? Check out  Vegetables that are ready in 60 days or less!!

~L

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