Seed packets are small, but they’re packed with information—more than most new gardeners realize. After more than 30 years of gardening year-round in Sonoma Valley, I’ve learned that understanding the details on a seed packet can mean the difference between a thriving crop and a disappointing one. Here’s how I read every seed packet before planting, and what each section really means for your garden.

Table of Contents

Why Seed Packets Matter

Seed packets are your first set of instructions for a successful crop. They tell you:

When to plant
How deep to sow
How long it takes to mature
How big the plant gets
How much space it needs
How to care for it

Although catalogs give you broader descriptions, the packet is the distilled, essential guide for getting your seeds from planting to harvest.

1. Variety Name & Type

This seems simple, but it’s important. Varieties differ enormously in flavor, days to maturity, size, disease resistance, and climate adaptability.

My experience tip:
Choose varieties with traits that match your climate. For Sonoma’s long summers, I look for heat-tolerant tomatoes and bolt-resistant greens. For winter planting, I choose cold-tolerant lettuces, peas, and root crops.

2. Days to Maturity

This number usually assumes from transplant for crops like tomatoes and peppers, and from sowing for direct-seeded crops like carrots, beans, or radishes.

Why it matters:

Helps fit crops into your growing season
Helps with succession planting
Helps avoid heat waves or frost windows

My experience tip:
For spring and fall crops, I choose varieties with shorter maturity times so they finish before heat spikes or cold snaps.

3. Sowing Instructions

This section includes:

Seed depth
Row spacing
Plant spacing after thinning
Sun requirements

These guidelines prevent the two biggest beginner mistakes: sowing too deeply and crowding plants.

My experience tip:
“Plant seeds twice as deep as they are wide” is a good rule—but root crops need exact spacing for best shape, so follow packet instructions closely.

4. Planting Window—When to Sow

Packets often include:

Indoor sowing dates
Outdoor sowing dates
Frost guidelines
A climate zone map or simple frost warnings

My experience tip:
In Sonoma Valley, I can sow cool-season crops far earlier and later than packet ranges because of our mild winters. Use your microclimate experience to adjust.

5. Germination Information

Many seed packets list:

Germination temperature
Germination days
Special instructions (scarify, soak, chill, etc.)

Why it matters:
Germination temperature is one of the most overlooked details—and one of the biggest reasons seeds fail.

My experience tip:
Warm-season crops (tomatoes, peppers, squash) germinate much faster on a heat mat. Cool-season crops germinate better at room temperature.

6. Growth Habit

Look for words like:

Determinate / indeterminate (tomatoes)
Vining / bush (beans, cucumbers)
Compact / dwarf / trailing

This dictates how much space you need and whether you must add trellises or cages.

My experience tip:
In raised beds, compact or bush varieties maximize space. In summer, vining crops on trellises help reduce disease and increase airflow.

7. Harvest Instructions

Packets often describe:

How to know when the crop is ready
Whether to harvest young or mature
Cut-and-come-again notes for greens

My experience tip:
Pay attention to flavor notes like “best harvested young” or “pick continuously.” These will improve your kitchen results.

8. Disease Resistance Codes

These appear as letters—V, F, PM, DM, TSWV, etc.

My experience tip:
In my garden, powdery mildew–resistant (PM) varieties make a major difference for summer squash and cucumbers. These codes save entire crops.

9. Seed Quantity

Pack quantities can vary widely—even for the same crop.

My experience tip:
For crops I grow heavily (lettuce, beans, cucumbers), I check seed count closely so I don’t run out mid-season.

10. Organic / Heirloom / Hybrid Labels

Open-Pollinated (OP)

Good for seed saving.

Heirloom

OP plus historical lineage. Often excellent flavor.

Hybrid (F1)

Reliable productivity and disease resistance.

My experience tip:
I use OP for lettuces, beans, peas, and tomatoes—and F1 hybrids for cucumbers, melons, and many squashes for their dependable disease resistance.

11. Company Notes

Some packets include:

Regional planting tips
Flavor reviews
Storage information
Best kitchen uses

These details often come from real trials. Over the years, I’ve found company grower notes to be very reliable.

Final Thoughts

A seed packet is more than packaging—it’s a roadmap. The more closely you read it, the fewer surprises you’ll have in the garden. After decades of comparing varieties, I’ve learned that understanding all the information on a packet can help you grow stronger plants, choose the right varieties, and get consistently better harvests year after year.