How to Read a Seed Packet

Seed packets contain a wealth of information, but for many gardeners—especially beginners—deciphering all the details can feel overwhelming. Understanding what’s on the packet will help you determine whether to start seeds indoors or sow them directly in the garden. Additionally, if you decide to start seeds indoors, the packet provides key guidance on how to do so successfully.

Let’s break down the most common elements found on a seed packet, how to interpret them, and how to use this information to decide where and how to start your seeds.

Common Information Found on a Seed Packet

A well-labeled seed packet typically includes the following information:

1. Plant Name and Variety

Each packet will list the plant name (e.g., Tomato) and the specific variety (e.g., ‘Brandywine’ or ‘Cherokee Purple’). Some varieties are better suited for specific growing conditions, so it’s good to research your selection.

2. Days to Maturity

This number indicates how long it will take for the plant to reach harvest from the time of planting. If a plant takes a long time to mature (e.g., 100+ days for some tomatoes or peppers), you may need to start it indoors to ensure it has enough time to produce before the first fall frost.

3. Planting Depth

Seeds need to be planted at the correct depth to ensure proper germination. This information is particularly useful when direct sowing, as deeper planting can reduce germination rates for small seeds.

4. Seed Spacing and Thinning

This tells you how far apart to space seeds when planting and how to thin seedlings once they sprout. If seeds are started indoors, this spacing may not apply initially but will be useful when transplanting outdoors.

5. Light and Temperature Requirements

Some packets specify the ideal temperature range for germination. Warm-season crops like peppers and tomatoes germinate best at temperatures between 70-85°F, often requiring heat mats if started indoors. Some seeds, like lettuce, require light to germinate and should be surface-sown.

6. Indoor Starting Recommendations

For crops that benefit from an early start indoors, the packet may indicate when to start seeds before your last frost date. A common recommendation is “Start indoors 6-8 weeks before last frost.”

7. Direct Sowing Guidelines

Packets often note whether a plant is best suited for direct sowing. For example, root crops like carrots and radishes do not transplant well and should be planted directly into garden soil.

8. Hardiness Zone or Frost Sensitivity

Some packets will include information on cold tolerance and the ideal USDA Hardiness Zones for planting.

9. Expected Germination Time

This tells you how long, on average, it takes for seeds to sprout. If seeds take longer than expected to germinate, conditions may need adjustment.

What’s Missing?

If a seed packet is missing key information, gardeners can take several steps to determine whether to start seeds indoors or direct sow:

1. Check the Seed Supplier’s Website

Many seed companies provide detailed growing guides on their websites, including best practices for sowing, plant spacing, and transplanting recommendations. Look up the variety online using the supplier’s name and the specific seed name.

2. Refer to a General Seed-Starting Chart

Many gardening resources provide seed-starting guides that list common vegetables, herbs, and flowers along with their preferred sowing methods. Books, online gardening blogs, and university extension websites often have charts that outline whether to start indoors or direct sow.

3. Consider the Type of Plant

Certain plant families follow general rules:

• Root crops (carrots, beets, radishes) should be direct sown.

• Leafy greens (lettuce, spinach, kale) can be either direct sown or transplanted.

• Fruit-bearing plants (tomatoes, peppers, eggplants) benefit from indoor starting.

4. Look at the Days to Maturity

If the seed packet lists a long growing period (e.g., 90+ days), it’s a strong indication that the plant should be started indoors in shorter-season climates.

5. Research the Germination and Growth Requirements

For missing details like germination temperature, light requirements, or soil preferences, check sources like:

• University extension offices (search for “[plant name] growing guide site:.edu”)

• Gardening books that focus on plant-by-plant growing instructions

• Online gardening communities where experienced gardeners share tips (Join the Just Grow Something Gardening Friends Facebook Group here!)

6. Experiment Cautiously

If no clear answer is found, try sowing a small batch indoors and another directly in the garden. Observe which method performs better in your climate and conditions and take notes for next season.

By using these strategies, gardeners can confidently make informed decisions even if their seed packet is lacking details!

Your Friend in the Garden,