THE GREEN THUMB ALMANAC 

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Annuals

On This Page!

  • Choosing Your Annuals
  • How to Plant and Care for Your Annuals
  • Best Plants for Summer Color
  • Season Extenders
What exactly is an "annual?"  The term "annual" is generally given to flowers and plants that are only grown for one season.  A true annual plant completes its life cycle in one season and then dies after producing seed.  There are many plants that we call annuals which are actually perennials (confusing huh?).  Perennials that bloom the first season but are unable to survive our harsh winter weather, or if they do survive, grow poorly the next season are also called "annuals."  Just remember "annuals" are plants that you have to replace annually!

Choosing Your Annuals

 

How much sun do you have?

The amount of sunlight that your garden receives is by far the most important criteria for deciding what annuals to plant.  Sunlight can be divided into 4 categories.

Full Sun (8 or more hours of direct sunlight).  Plants in this category must receive at least 8 hours of sunlight in order to bloom well.  To little sun will result in weak, spindly growth and few blossoms.
Part Sun/Part Shade (less than 8 hours of direct sunlight).  Plants in this category require some shade during the day, often during the hottest part of the day like the afternoon hours.  If your sun is mainly in the afternoon try mixing in some "full sun" annuals as well.
Full Shade (no direct sun).  All plants require at least a little sun in order to bloom well.  Full shade annuals are often plants which are mainly grown for their foliage, not their flowers.
Sun or Shade.  These are plants which can survive almost anywhere.  Many "shade" plants can survive in sunny areas if there is additional irrigation.
 

Remember that these categories are flexible.  Soil conditions, availablity of water, direction and time of day of sunlight and seasonal changes will all affect how your annuals perform.  Experiment by planting annuals in different parts of your garden to determine what grows best for you.  Below is a short list of annuals and their sunlight requirements:

Full Sun

Alyssum
Amaranthus
Angelonia
Ageratum
Blue Daze
Calendula
California Poppy
Canna
Celosia
Cleome
Cosmos
Dahlia
Dianthus
Dusty Miller
Euphorbia
Gaillardia
Gazania
Geranium
Gomphrena
Helenium
Lantana
Lisianthus
Marigold
Melampodium
Mexican Heather
Nicotiana
Nierembergia
Ornamental Basil
Ornamental Grass
Ornamental Pepper
Papyrus
Penta
Periwinkle
Portulaca
Salvia
Scaevola
Snapdragon
Strawflower
Sweet Potato Vine
Verbena
Zinnia

Sun or Shade

Begonia
Sun Coleus
Colocasia

Part Sun   Part Shade

Browallia
Fuschia
Gerbera Daisy
Impatiens
Lobelia
Torenia

Full Shade

Caladium
Shade Coleus
Please note:  If your part sun area primarily receives sunlight in the afternoon; we recommend trying some of the full sun annuals as they are more adaptable to hot afternoon temperatures.
 

If you garden in the heartland, check out the Kansas State Prairie Star program.  Prairie Star annuals are flowers tested by K-State at their Research and Extension Center in Olathe, Kansas.  These plants are selected for their superior performance in the harsh growing conditions found in the heartland. 

How to plant and care for your annuals!

All garden plants require some care.  For your annuals to perform well it is best to start with good soil.  Always amend your flower beds with organic matter.  This can be purchased as a ready-to-use compost or you can create your own compost at home.  Dig this into the soil before planting.  If you are planting in containers add a slow-release fertilizer to a good quality potting mix before planting.

 

Annuals can be started from seed or from container grown plants purchased at your local garden center.  Container grown plants will grow larger in a shorter period of time.  Start your seeds indoors early (see our seed starting page for more information).


Watering is very important, especially when your annuals are young.  It is best to water deeply but infrequently rather than giving them a little water every day.  Check the tag or seed packet for information regarding how much water your annuals would prefer.  (See our page on watering for more information.)

Deadheading, or removing spent blossoms, is a very important task.  Since annuals are "programed" to produce seeds in one season, it is a good idea to trim off blooms as they fade to keep the plant from producing seed.  This will keep your annuals blooming at their best.  Please don't be alarmed if your plants take a rest during the hottest part of the summer.  Flower production is often affected by extreme heat conditions.

Remember to feed your annuals often.  It takes a lot of energy to continually produce flower blossoms.  A regular dose of a liquid fertilizer when watering or an application of a granular fertilizer will be most appreciated.  (See our page on fertilizers for more information.)

Of course the MOST important thing for you to do is to sit down with a cold drink and admire your garden.  Flowers are meant to be enjoyed!

Best Plants for Summer Color - What Do the Experts Like?

  1. Lantana 'New Gold'
  2. Begonia 'Dragon Wing'
  3. Impatiens 'Merlot Mix'
  4. Ruellia 'Mexican Petunia'
  5. Verbena bonariensis
  6. Salvia 'Wendy's Wish'
  7. Angelonia 'Serena'
  8. Mandevilla 'Alice Du Pont'
  9. Cosmos 'Bright Lights'
  10. Gomphrena 'Fireworks'
- Tony Range, Horticulture Manager, St. Louis Zoo
  1. Begonia 'Dragon Wing' & 'Sinbad'
  2. Chlorophytum comosum 'Variegata'
  3. Ipomoea 'Chillin' Limeade'
  4. Melinus nerviglumis 'Savannah' & 'Champagne'
  5. Musa 'Siam Ruby'
  6. Ricinus communis gibsonii
  7. Solenostemon 'Glennis', 'Redhead' & 'Royal Glissade'
  8. Spilanthes oleracea 'Toothache Plant'
  9. Xanthosoma 'Lime Zinger'
  10. Zinnia 'Zowie Yellow Flame'
- Julie Hess, Senior Horticulturalist, Missouri Botanical Garden
  1. Petunia 'Vista Silverberry'
  2. Melinus 'Pink Champagne'
  3. Coleus 'Sedona'
  4. Lobularia 'Snow Princess'
  5. Lantana 'Luscious Citrus Blend'
  6. Zinnia 'Righteous Red'
  7. Pentas 'Butterfly Pink'
  8. Zinna 'Profusion Orange'
  9. Caladium 'Strap White Wing'
  10. Purple Hyacinth Bean
- Anne Wildeboor, Seasonal Display & Special Events, Powell Gardens
  1. Ageratum 'High Tide Blue'
  2. Alternanthera dentata 'Purple Knight'
  3. Capsicum annuum 'Black Pearl'
  4. Coreopsis verticillata 'Full Moon'
  5. Cynara cardunculus 'Cardoon'
  6. Duranta 'Cuban Gold'
  7. Hibiscus 'Moy Grande'
  8. Pennisetum 'Princess Molly'
  9. Rudbeckia nitida 'Herbstonne'
  10. Zinnia 'Profusion Double Cherry'
- Sarah Lowe, Asst. Botanical Garden & Horticulture Manager, Cheekwood Botanical Garden and Museum of Art

Season Extenders!

Don't let the cold temperatures of early spring and late fall keep you from enjoying colorful flowers.
Here is a list of annuals that  perform well even when it  is  cold:
Annuals that can take a light frost
  • Bidens
  • Lobularia (Alyssum) 'Snow Princess'
  • Calibrachoa (Million Bells)
  • Diascia
  • Daisys (Marguerite)
  • Dusty Miller
  • Nicotiana
  • Ranunculus
  • Pansy/Violas
  • Petunia
  • Snapdragon
  • Verbena
  • Vinca Vine

Annuals that like cold but are not frost tolerant

  • Bacopa
  • Brachycome
  • Fuschia
  • Helichrysum (Straw Flower)
  • Nemesia
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