Annual and Perennial plants

How Can You Tell If A Plant Is An Annual Or A Perennial?

In Gardening by Jamie

Do you know an often overlooked secret of long-lasting flower garden beds? Planting both annual and perennial plants. Too many annuals will have you starting from scratch every year. Too many perennials and your blooms will be short-lived. But how do you know which plants are annual and which are perennial?

First you must identify the plant, whether through the tag, seed packet, or field guide. Often, it’ll say on the seed packet. Check the zone too to see if it’s perennial in your region. In general, if a plant dies in the winter season, it’s an annual, but if it returns the following year, it’s a perennial.

But lets get into more details below about perennial and annual plants.

What’s the Difference Between Annual and Perennial Plants?

The difference between annual and perennial plants is:

Annual Plants Only Live for a Year (One Growing Season)

They bloom throughout the growing season and many can reseed themselves (unless sterile), so even if they die one year, they’ll return the next. Many popular flowers are annuals. The latin name may include “annuus” or “annua”, meaning annual.

Perennial Plants Live for 3 or More Years

Flowering perennials typically flower for only a short period before either returning to green foliage or dormancy (looking like it died). Many native plants and houseplants are perennial. Although annual and perennial are usually used to talk about flowering plants, non-flowering plants like trees, shrubs, and ferns are perennial too. The latin name may include “perennis” for perennial.

Your growing zone and climate will also determine whether a plant is annual or perennial. Lavender, peppers, and even petunias are perennials in mild climates, but grown too far north, and they become annuals. Likewise, some plants, like geraniums, are annuals in hotter climates.

To figure out if a plant is perennial in your zone, check the growing zone. If you’re outside of the growing zone, then it will be an annual. (For container plants, subtract one growing zone since it doesn’t have the protection of the soil. You can also extend a perennial container plant’s life by bringing it inside to overwinter.)

What’s a Biennial?

A biennial plant lives for 2 years, usually spending the first year establishing itself with roots and leaves (you may only see a short stem and foliage), then flowering and fruiting/seeding the next. After the second year, the plant dies. Their scientific name may include “biennis” for biannual.

Examples include carrots, forget-me-nots, foxgloves, and hollyhocks.

How Do I Find Out What Kind of Plant I Have?

The easiest way to know what kind of plant you have is to read the tag or seed packet.

But many times, we gardeners end up inheriting plants, whether it’s in the garden of our new house or a plant given to us by a friend, or even accidentally throw out a new plant’s tag without remembering to record it. Sometimes, the tag is just plain vague (it’s a houseplant! Really?).

app that use photo recognition

One of the quickest ways to find out what plant you have is with a plant identification app. These apps use photo-recognition and machine learning AIs to match a photo of the plant to plants in their database. Depending on the plant and the app, it may take some finagling to find the best match. Ensuring that you submit quality photos with the most identifiable features of a plant (and being able to match those features to the results) will increase accuracy.

Otherwise, you can look through field guides or garden plant encyclopedias, using the plant’s features (leaf shape, leaf arrangement, stem, flower, bark) to narrow down the possibilities. (This is basically what a plant identification app does, but it speeds up the process.)

And if you get stumped, ask for help on a houseplant or gardening forum (Reddit is awesome for this). Post 3 to 5 clear photos of different plant parts to give people all the details they need to make an accurate identification.

Are Plant Identification Apps Accurate?

Plant identification apps claim that they have at least 96% accuracy, but results in the field can be more hit and miss. Factors that affect accuracy include:

  • How easily identifiable a plant is using morphology (some species can only be accurately identified by genetic testing)
  • Clear, focused image of a whole, ideal specimen (leaf or flower)
  • Smartphone camera hardware and image processing software
  • Database size and the plants included
  • Photo recognition software

Even when plant identification apps fail, they’re still a great first step.

Examples of Plant Identification Apps

There are a ton of plant identification apps ready to download — so many, in fact, that it can be hard to decide which one to use!

First, narrow down what plant you’re trying to identify. Is it a plant found in your garden? Is it a houseplant? Is it a plant along a trail? Most apps tend to focus on one of those areas, so finding one that suits your needs will help you get an accurate identification sooner. (Don’t be afraid to download multiple!)

A few top apps include:

Need more help? Check out our guide to the 5 Best Free Apps to Help Identify Plants.

Final Thoughts

Figuring out whether a plant is an annual or a perennial is as simple as knowing what plant it is and then looking it up. You can also observe the plant. If it flowers throughout the growing season, it’s probably an annual. If it flowers for a short time but comes back year after year, it’s probably a perennial.