Whether you're shopping at a nursery or browsing online for plants, reading plant labels can help ensure you're making the best choice for your garden. While plant labels may seem straightforward, there's more information on them than meets the eye. The difference between having a plant that thrives or one that struggles can be as straightforward as reading the label carefully. Here's a guide to help you decode those labels and pick plants best suited to your gardening goals. This article focuses primarily on labels for annual vegetables and flowers.
Front of Plant Label
The front of the label may have a picture of the plant. Sometimes plant labels can be accidentally put into the wrong container so be sure that the picture matches what is in the container. Also, if you want to choose several different colors of the same plant, make sure that the label matches the color you want. The leaves may look identical, but the flower colors would be different. Sometimes, flowers in the nursery will be in different stages - some in bloom and some not blooming yet - so you can look for the colors you want and they should match the labels.
Common Name and Botanical Name
Most plant labels will show both the common name and botanical (scientific) name on the front of the label. The common name is what people usually call the plant (like “sunflower” or “basil”), while the botanical name is a two-part Latin name, such as Helianthus annuus for sunflowers. The botanical name helps avoid confusion because two different plants that may have the same or similar common names will have different botanical names. The botanical names are unique to every plant. For example, the common name “sage” can refer to many different varieties in the Salvia genus, although every salvia variety has a unique botanical name.
Why it matters
If you're searching for specific care information, the botanical name will provide more accurate results. Two different plants may have the same or similar common name so this can be confusing. However, common names are easier to remember and useful for talking with other gardeners or personnel at a nursery.
Plant Hardiness
Hardiness zones indicate the range of temperatures in which a plant can survive. The USDA Plant Hardiness Map divides North America into 11 hardiness zones. Zone 1 is the coldest; zone 11 is the warmest. The USDA Plant Hardiness Zone Map helps gardeners determine which plants are most likely to survive winters in a given geographic area. The map is based on the average annual minimum winter temperature, divided into 10-degree F zones. The map is available as an interactive GIS-based map; users may also simply type in a ZIP Code and find the hardiness zone for that area. Find your USDA plant hardiness zone.
In the San Francisco Bay Area the hardiness zones range from USDA zones 10a-10b for coastal areas and 9a-9b for inland areas. Plants that are labeled as only appropriate in zone 10, for example, will likely not survive a frost in the Tri-Valley area (Livermore, Pleasanton, Dublin), which is in zone 9.
While less common on plant labels than the USDA Hardiness Zones, Sunset Climate Zones are a good reference to know because they take into account more climate factors such as length of growing season, timing and amount of rainfall, summer highs, winter lows, wind and humidity. Because they take into account more factors, the Bay Area is broken down into more zones, ranging from 14-17.
Why it matters
Choosing a plant outside your hardiness zone could mean it won't survive your winter (if it's too cold). This is one of the most important pieces of information on a plant label and can be the difference between success or failure for a plant. For plants in controlled environments such as greenhouses or indoors, the USDA hardiness number becomes less important.
Sunlight Requirements
Plant labels often include sunlight needs, using terms like:
- Full sun: At least 6 hours of direct sunlight per day
- Partial sun/partial shade: 3-6 hours of sunlight.
- Full shade: Less than 3 hours of direct sunlight
Why it matters
Sunlight is crucial for photosynthesis. Matching a plant's needs to the location in your garden helps it grow with vigor, flower, or fruit as expected. Plants that are labeled for Full Shade are best planted where there is no direct sun. Generally, if a plant is labeled for Full Shade, they will not thrive in full sun and may even die. Plants that require the Full Sun often have trouble growing and flowering in areas of high shade.
Watering Needs
Watering instructions typically range from "low" to "high," indicating the moisture levels that best support the plant. Some labels might also note if a plant is drought tolerant.
Why it matters
Over- or under-watering can stress plants. Matching a plant's needs to your climate and watering habits can make a big difference. This is also important for grouping water compatible plants in landscaping. Plants that have similar water requirements should be planted together so that all get the proper amount of water. Planting a drought tolerant plant in an area of non-drought tolerant plants can lead to over-watering or even killing the drought tolerant plant.
A simple test to determine soil moisture is dip your index finger into the soil near the stem of your plant up to about your first knuckle. If the soil feels dry and your finger comes out clean, then it's probably time for some water. If the soil around your fingertip is still moist and a little bit of soil sticks to it, then it may not be time yet to water.
Mature Size (Height and Width)
This indicates how big the plant will be when fully grown, usually measured in feet or inches.
Why it matters
Knowing the mature size helps you plan where to plant it. You wouldn't want a plant that will eventually grow too large for a small space or shade out other plants. This is especially important when considering planting trees and shrubs near homes and buildings. In general, trees that are 30 ft or less should be at least 10 ft away from any structure. Trees that are greater than 30 ft tall should be 20 ft + away from buildings.
Spacing Recommendations
This is the distance you should leave between plants, helping to ensure they have enough room to grow without crowding. There is some leeway here in how close plants can be planted. Some vegetables can be planted in between other vegetables. For example, leafy greens can be planted between root crops such as carrots, beets and radishes since they have different above and below ground space requirements. Climbing plants grown on trellises can often be planted close together such as climbing beans and peas and indetrminate tomato plants.
Why it matters
Proper spacing helps improve air circulation, reducing the risk of disease, and gives each plant enough room for its roots. It is important to think about the size at maturity both above and below the ground. For example, if carrots or beets are planted too close together it might inhibit the size of the root underground.
Growth Rate
A plant's growth rate might be described as slow, moderate, or fast. This gives an idea of how long it will take for the plant to reach its mature size. Typically, perennials will grow more slowly than annuals, which only have one season to reach maturity.
Why it matters
Fast-growing plants are ideal for filling in spaces quickly, while slow growers may need more patience but are often longer lasting. It is often a good strategy when landscaping to have some permanent perennials with annuals added for color in between that are replaced every year. In warmer years, some annuals may survive the winter and come back again in the Fall.
Bloom Time and Flower Color
For flowering plants, labels often indicate when they will bloom (such as "spring," "summer," or "fall") and the color of the flowers. The picture on the front of the label will often show an example of the plant, if it's a flower, it will show the color(s) of the flowers. This can be useful in picking out plants of the same type but different colors.
Why it matters
Planning your garden with bloom times in mind ensures continuous color throughout the seasons.
Special Requirements or Attributes
Some plant labels may include additional information, such as:
- Soil preference: Whether the plant prefers acidic, neutral, or alkaline soil
- Special care instructions: Such as pruning needs or winter protection
- Pest and/or disease resistance: Some plant varieties have been bred to be resistant to common diseases associated with that plant. For example, VFN resistance on tomatoes means it is resistant to Verticillium Wilt, Fusarium Wilt and Nematodes. Some squash varieties have been bred to be resistant to powdery mildew, as another example. Plants with strong deer resistance will sometimes indicate that on the label.
Why it matters
These specifics allow you to give extra care or avoid plants that may be challenging to maintain in your region. Looking for plants that are resistant to the common diseases for that plant can help avoid those diseases and avoid the necessity for crop rotation.
Toxicity Warnings
Labels on some plants (like lilies, foxglove or oleander may include warnings about toxicity to pets or humans.
Why it matters
If you have children or pets, this information is crucial for making safe choices. Also, this information can indicate how you should interact with the plant, for example, always wearing gloves, avoiding touching eyes while working with the plant, washing hands afterwards, and other precautions
Final Thoughts
Understanding plant labels can help you make smart choices that lead to a thriving, beautiful garden. By paying attention to these details, you'll be able to choose plants that fit your environment and care preferences. Saving the plant labels will give you information on the plants in your garden that is a useful reference source. Happy gardening!
References
- USDA Plant Hardiness Map
- Sunset Climate Zone Map
- Hang on to the Plant Labels
- 8 Water Wise Tips You Can Start Today
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