An image of a summer garden with purple lupines blooming in the front, pink yarrow in the middle and a wall of sweet peas in the back with the full moon rising on the horizon.

Annuals, Biennials and Perennials - Their Differences and How To Grow Them

Spring is here! You got your seeds and you are ready to start planting your garden.

So you look at the seed packet and start reading the planting instructions. 

You might come across words like:




Tender Perennial

Hardy Annual

But what do those mean and what’s the best way to grow each?

Don’t worry let me break it down for you!

A patch of Carnation flowers growing in the garden.

The difference between Perennials, Annuals and Biennials

Annual: An annual plant lives for a single growing season. They complete their entire life cycle going from seed, to flower, and back to seed, then dying off. Annuals are considered the easiest to grow from seed but you have to replant them if you want to welcome them back in your garden every year. 


Hardy Annual: Hardy Annual flowers live for 1 season like annuals but are cold and frost tolerant. They can be planted in the fall prior or early spring to get early blooms. I’ve created a guide on hardy annuals that you can grab here


Biennial: Biennials usually take two growing seasons to complete their life cycle. In its first growing season, the plant produces only foliage. In its second year, it will flower and set seed.


Perennial: A perennial flower will go from seed to seed within one season but it does not die at the end of the season. It  can be expected to live at least three years, or in some cases much longer. 

BTW, many perennials can be grown easily from seed. You can skip buying potted plants at the nursery and grow your own (if you are into that kind of thing)! I’m growing a bunch of lavender plants this year from seed and so far it’s been a breeze.


Tender Perennial: A tender perennial is a plant that maybe a true perennial in warmer climates but can be grown as an annual in colder climates where winter kills them off. 


Let’s breakdown how each plant grows and the best way for your garden!


A patch of Bicolored green and red zinnias (Queeny lime red zinnias)

How to grow Annual Flowers

Most annual flowers are heat loving (unless they are hardy annuals) and will not tolerate cold temperatures and frost. They can be started indoors but can only go outside after all of the dangers of frost have past. You can google your average last frost date using your zip code. 

Annual flowers like Zinnias, Cosmos and Sunflowers are super easy to grow, quick to flower  (60-90 days) and will grow in pretty much any garden. Most Annual flowers can be planted as close as 9" apart. Not only does this make a more impactful display but also makes the flowers grow taller as they try to compete for sunlight. 

For a list of Hardy Annual flowers and how to grow them click here.


How to grow Biennial Flowers

Biennial flowers need an entire season to get established as plants before they bloom the next year. There are 2 different ways that you can grow them. 

  1. The first option is to plant them in the Spring, then baby and take care of the plants through summer, fall and winter until they blooms the following year. 
  2. The second (and my preferred) option is to plant them in the fall for flowers the following season. This cuts down months of tending to the tender little plants, weeding, watering and protecting them from pests.  

 Make sure that they don't get shaded over by other plants in your garden and keep up with the weeds!

Tip: When the plants are blooming sow the next round of seeds for the following season. Many biennials are also great re-seeders and might come back year after year on their own.


How to grow Perennial flowers

Perennial flowers are an amazing addition to your garden because they bloom after the tulips are done and before the heat loving annuals are ready. Not to mention the time and work that you don’t have to do to plant them every year!

Some perennial seeds can be sowed outside (for a stratification period) and some require to be started indoors. Read the seed packet for the recommendation. Since the plants are hardy they can be either planted in the fall (especially in milder regions Zone 6+) or early spring. No need to wait for your last frost date. Stick them in the ground as soon as the soil can be worked. 

Plant perennial flowers a bit further apart (12") than you would annuals since they will grow larger over the years.

Beware of the flowers that are considered tender perennials (Eucalyptus, Rudbeckia, Carnations, some Foxglove varieties) especially if you are in the North. You might need to treat these flowers as annuals and replant them every year. 

Example: we are in the Pacific Northwest zone 8b and our climate is relatively mild. I have successfully overwintered Rudbeckia and Carnations. We had some freezing temperatures this winter and some of my Eucalyptus did die while the bigger plants survived.


The back of a UTV full with buckets of fluffy pink and white cosmos flowers.

List of Flowers by Category

To grow a truly interesting and varied garden you need a flower from each category. They will grace your landscape with beautiful flowers throughout the season never leaving a dead spot in your garden.


  • Bachelor Button (Hardy Annual)
  • Celosia
  • Cosmos
  • Larkspur
  • Snapdragons (Hardy Annual)
  • Stock (Hardy Annual)
  • Sweet Peas (Hardy Annual)
  • Sunflowers
  • Zinnia


  • Columbine (perennial)
  • Foxglove
  • Echinacea
  • Hollyhock
  • Sweet William
  • Sweet Rocket


  • Black-Eyed-Susan (tender Perennial)
  • Carnations (tender Perennial)
  • Cone Flower (Echinacea)
  • Dahlias
  • Delphinium
  • Iceland Poppy
  • Lavender
  • Lillies
  • Lupine
  • Mint
  • Peonies
  • Phlox 
  • Scabiosa
  • Yarrow


    I hope this is helpful and inspires you to grow the most amazing garden!

    Leave me a comment and let me know what you are growing this year.

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