How to Read a Plant Tag

I admit it, I’m a label reader. You’ll find me scanning the fine print on boxes and bags at the food market, trying to discern any mystery ingredients. And when I’m deciding on a new addition to my garden, you can bet that I read every plant tag. Some might think my label reading habit is obsessive, but it was born after years of making mistakes – and wasting money – that could have been easily avoided.

In your neighborhood, do you see yew shrubs and forsythias blocking sidewalks? Rhododendrons blocking windows? Forty-foot pine trees planted 5 feet from the side of a house? A fifty-foot maple lifting the sidewalk?

Yea, me too. That homeowner could have saved themselves a lot of grief and maintenance if they’d read the plant tag. A quick look at the mature size would have told them that they needed a few more feet of clearance. Yes, that tree looked perfect, maybe even too small when it was first planted, but twenty years later, it looms over the house like the specter of doom.

To help you determine if a tree is right for your property or a plant is perfect for your flower or vegetable garden, here’s an explanation of what the terms on plant tags and seed packets mean.

Plant tag and seed pack terms:

Full Sun, Part Shade, Full Shade / Light Requirements / Exposure

This seems simple on the surface, but many don’t take the time to look at how light hits their property. Full Sun means that your plant must receive at least 6 hours of direct sunlight each day. As a rule, that means the north or west side of your home probably won’t suffice, but the east side might and the south side definitely will – depending on surrounding trees and buildings that might cast shadows.

To complicate things, the west side of your home might actually face slightly northwest or southwest, which changes the amount of light considerably. The only way to know, is to take notes on a summer day as to what time the sun hits each area around your home, and for how long. Plants only thrive under the light conditions they’re accustomed to.

Mature Size / Average Size

When it comes to shrubs and trees, this one’s an essential check. That three-year-old Ponderosa Pine that’s 5 or 6 feet when you plant it may be hard to imagine as an 80-foot behemoth, yet that’s what it will be in thirty or forty years. Its roots will extend at least twice as far as its canopy, so if it’s planted too close to your home, the roots might damage your foundation. Plan accordingly.

Growth Habit

This term refers to the way the plant grows: climbing, mat forming, clumping, erect, open, spreading, etc. On trees and shrubs, it refers to the shape of the plant: columnar, oval, vase, weeping, pyramidal, or round.

Cold Hardiness / Hardiness

You generally don’t need to worry about this if you’re buying at your local garden center, because anything sold there should be fine for your area. But if you’re shopping online, it’s a must. Look for the word Zones or Hardiness, or a version or combination of the two. This data tells you if that plant/tree/shrub can survive winter in your area. Check your local hardiness zone here.

Seed Spacing / Spacing

This one’s pretty obvious – how far apart to plant your seeds and how far apart to set each plant, measured center to center.

Days To Germination

How many days it will take from the day you plant the seed until the first leaves appear.

Days To Maturity

For most fruits and vegetables, this means how many days are required from the time you plant the seed until the day you harvest the crop. In the case of tomatoes, it refers to the time required from the day you plant the seedling until harvest.

Disease Resistance

Some hybrid plants, including many fruit and vegetable crops, have been bred to resist certain diseases like powdery mildew, apple scab, or verticillium wilt. This resisitance is indicated by symbols on the plant tag or seed packet, such as:

• LB – Late Blight
• PM – Powdery Mildew
• RKN – Root Knot Nematodes
• T or TMV – Tobacco Mosaic Virus
• V- Verticillium Wilt

Growth Rate

This term is pretty inexact: Slow, Medium, Fast. But there are so many variables which determine how your plant will grow, like sunlight, soil, and rainfall, that this isn’t of much use.

Spacing After Thinning

With vegetable crops like carrots, you sow many seeds and then thin them out once the first leaves appear. This term refers to how much space should be left between each plant after the first leaves appear so they have ample room to mature.

Common Name and Latin / Scientific / Botanical Name

The common name for a plant is the name by which we all know it – for instance, Northern Highbush Blueberry. It’s botanical name is Vaccinium Corymbosum. The botanical name is an international standard, as plants can be known by different common names, depending on what part of the world you’re in. For instance, the Highbush is also known as Blue Huckleberry and Swamp Blueberry here in the U.S. Having the scientific name assures that if you buy a second plant, you’re getting exactly the same cultivar. It also helps scientists keep their plants straight.