Gardening decisions depend on accurate information about specific plants and local conditions. This lesson explains what the common information sources are, what they contain, and how to read them.
Assumed audience
- Reading level: general adult.
- Background: has completed the lessons on plant basics and light and climate. Understands the concepts of species, cultivar, frost dates, hardiness zones, and days to maturity.
- Goal: be able to find and interpret the information needed to decide what, when, and how to plant.
Seed packets
A seed packet is the primary information source for a specific cultivar. It typically contains:
- Species and cultivar name: identifies exactly what the plant is.
- Description: a brief summary of the plant’s traits — size, color, flavor, disease resistance, and intended use.
- Light requirement: usually stated as “full sun,” “partial shade,” or “full shade.”
- Planting instructions: when to plant (relative to frost dates), whether to direct sow or start indoors, planting depth, and spacing.
- Days to maturity: the number of days from planting or transplanting to harvest.
- Germination information: expected germination time and ideal soil temperature for germination.
How to read a seed packet
- Start with the planting instructions and timing. Determine whether the plant is direct-sown or started indoors, and when relative to your local last frost date.
- Check the days to maturity against your frost-free growing season. If the days to maturity exceed the frost-free season, you will need to start seeds indoors or choose a shorter-season cultivar.
- Note the light and spacing requirements and compare to your growing site.
- Read any notes on soil preferences, watering, or special care.
Seed catalogs
Seed catalogs are published by seed companies, usually annually. They contain the same information as seed packets but for a large selection of cultivars, often with more detail:
- Regional suitability: some catalogs note which cultivars perform well in specific climates.
- Comparative information: catalogs allow comparison between cultivars of the same species — one may mature faster, resist more diseases, or tolerate more heat.
- Growing tips: many catalogs include brief growing advice beyond what fits on a packet.
Regional seed companies (those based in and selling for a specific climate zone) are especially useful because their offerings are pre-selected for local conditions.
Cooperative extension publications
Cooperative extension services are university-affiliated programs that translate agricultural research into practical advice for growers. Every U.S. state has one; other countries have equivalent programs under different names.
Extension publications are among the most reliable gardening information sources because they are:
- Regionally specific: written for the climate, soil, and pest conditions of a defined area.
- Research-based: recommendations come from controlled trials, not anecdote.
- Free or low-cost: most are available online at no charge.
Common extension publications relevant to gardening include:
- Planting calendars: specify when to plant each crop in a given region, based on local frost dates and growing season length.
- Crop guides: detailed instructions for growing a specific vegetable or fruit, including recommended cultivars, planting dates, spacing, fertilizer rates, pest and disease management, and harvest timing.
- Soil test interpretations: guidance on how to read a soil test report and what amendments to apply.
- Pest and disease identification guides: photographs and descriptions to help diagnose problems, with management recommendations.
To find extension publications for a specific area, search for the state or province name followed by “cooperative extension” or “agricultural extension.”
Plant labels (nursery starts)
Plants purchased as starts from a nursery or garden center come with a label (stake or tag) that provides:
- Species and cultivar name.
- Light and water requirements.
- Mature plant size (height and spread).
- Hardiness zone rating (for perennials).
Nursery labels are brief. For detailed growing information, use the cultivar name from the label to search extension publications or seed catalog databases.
Experienced local growers
Neighbors, community garden members, and farmers market vendors who grow in conditions similar to yours can provide information that no publication captures:
- Which cultivars actually thrive in the specific microclimate of your area.
- When they actually plant and harvest (which may differ from published averages).
- What pests and diseases are most problematic locally and what management strategies work.
Local knowledge supplements published sources. It is most useful when confirmed against at least one research-based source (such as an extension publication) to guard against practices that work by luck rather than by principle.
Organizing information from multiple sources
Different sources may give slightly different advice. When they conflict:
- Prioritize the most regionally specific source. A local extension guide is more relevant than a national gardening book.
- Prioritize cultivar-specific information over species-level generalizations.
- Prioritize research-based sources (extension publications, seed company trial data) over anecdotal recommendations.
- Record the source of each piece of information so you can revisit and compare as you gain experience.