New Mexico Master Gardeners
 

 

Annuals 

by Ellen Reed, Lifetime Master Gardener

            Annuals grow from seed to seed in one season and die from a hard frost.  Some tender perennials, tropicals and house plants are grown out doors in climates where frost occurs.  They develop rapidly from cuttings or seeds to make a show in the summer garden.  Some may perennialize in warm microclimates near a building or cement patio where there is wind protection.  Winter moisture may influence whether a plant will be hardy; either too much or too little water may be fatal.

            Annuals are usually easy to grow, give a long season of color (bloom), fill in rapidly and are inexpensive especially if you grow your own from seed.  Some self sow and only need thinning.  Others must be dead headed (faded blooms removed) to prevent their overtaking the whole garden, to keep them blooming vigorously all season or to prevent hybrid plants from being overgrown by vigorous reversions to less desirable varieties.

            Annual plants can be used for color spots to fill in a bed of shrubs and perennials or to fill in where spring bulb foliage has left a void.  Herbs grown as annuals such as parsley, or vegetables such as Swiss chard ‘Bright lights’, red leaved lettuce or corn can be interplanted to provide color or height in a summer garden.

            Seeds of hardy or semi-hardy annuals that may be scattered in fall or early spring include sweet alyssum, annual baby’s breath, Shirley poppy, opium poppy, California poppy, bachelor buttons, larkspur and nigella.  Under favorable conditions they may self sow.  Pansies, petunias, snapdragons, and dianthus are usually easier bought in 6 packs and may be planted before the last frost or in the fall.

            Non hardy plants which need warm weather to thrive, are cosmos, marigold, nasturtium, zinnia and sunflowers all of which grow rapidly from seed planted in warm soil.  Other warm season annuals for sun such as Zinnia angustifolia “white stars’ and ‘gold stars’, annual vinca (Catharanthus), verbena, ageratum, statice, lobelia, amaranth, globe amaranth, gaillardia, portulaca and salvia are easier planted from six packs.  Annuals for shade include impatiens, fibrous begonias, and coleus.  Annual vines such as scarlet runner beans, morning glory, cardinal climber, thunbergia and gourds grow rapidly from seed and can cover a trellis or fence in one season.

            Children especially, enjoy planting large seeded, fast developing plants such as marigolds, nasturtiums, bachelor buttons and sunflowers. They will also enjoy a teepee constructed from bean poles and planted with vines to make a shady structure for them to play in.

            Most annuals need a minimum of a half day of sun and regular watering. They tend to be shallow rooted and since they live only one season, optimum bloom is desired.  Most benefit from the addition of compost to the soil to help it retain moisture.  A light application of soluble nitrogen fertilizer is beneficial for the longest and largest bloom.  Most soluble commercial fertilizers also contain various amounts of phosphate and potassium.  The phosphate translocates slowly in the soil and an abundance of potassium is naturally available in most of Bernalillo County soils.

            When planting seeds, cover them lightly with sand or vermiculite to keep the soil moist until they sprout.  Many annuals benefit from having the tip of the central shoot removed, so that side branches produce a more compact plant.  Usually this delays blooming only slightly.  Often removing spent blooms or lightly trimming back the whole plant in midseason, followed by a light fertilization results in renewal of blooming vigor.  Experience will show which and how much to thin self sown seedlings.

Growing annuals can be a rewarding way to establish a colorful garden and to experiment with color, contrast and form. Because of our altitude and low rainfall and high summer temperatures some annuals do better than others in New Mexico. The following list gives some of the ones that do best.

 Common name  

Botanical name

 Light 

Height in inches  

Colors

African Daisy  

Arctotis, Dimorphotheca and Osteospermum

S  

10 - 24

0 Y R

Floss Flower    

Ageratum

S, LSh

6 .12

L B P W

Baby’s Breath  

Gypsophila elegans

S  

12.24

W P

Bachelor’s Button

Centaurea cyanus         

S, L Sh

12- 36

P B W

Balsam, Snapweed, Touch-me-not  

Impatiens balsimina

LSh, Sh  

8 -30

P W Ro Li, R

Amethyst flower  

Browallia

LSh,Sh  

8 -16  

LWB

China Aster

Callistephus chinensis

S,LSh

12-36

WYPRBLP

Cockscomb

Celosia 

S  

6 .24  

RBrYGoOP

Cosmos  

Cosmos

S  

18-36

OGoPWR

Creeping Zinnia  

Sanvitalia procumbens

S

6

Y/Pu

Annual Phlox  

Phlox Drummondii

S,LSh

6 - 20

W P Pu V  

Dusty Miller  

any one of 6 or more species of gray foliaged plants. i.e.. Artemisia, Centaurea, Chrysanthemum, Lychnis, or Senecio

S     

8 - 15

Gray leaves

Fibrous-rooted Begonia     

Begonia semperflorens

Sh

6 - 16  

R P W  

Four O'clock  

Mirabilis jalapa w/ tuberous root

S,LSh

18-30  

WRYP

Globe Amaranth  

Gomphrena

S  

9 - 24

Pu  L A W

Impatlens  

Impatiens wallerana

LSh, Sh  

6 - 18  

W A P L  

Joseph’s Coat  

Amaranthus tricolor

S

30 - 60

R V G   (leaves)

Larkspur Consolida ambigua, Delphinium ajacis S, Sh 24-60 BPWLRSal

Lobelia  

Lobelia erinus

LSh,Sh  

4 -8  

BPuW

Madagascar Periwinkle  

Catharanthus roseas, Vinca rosea

S, LSh

6 - 1

W P R

Marigold, African  

Tagetes erecta

S

10- 30  

W 0 Go  

Marigold, French  

Tagetes patula

S

6 - 18

V 0 A Go  

Mexican Sunflower  

Tithonia rotundifolia

S

48 - 60  

 0

Morning Glory  

Ipomoea nil or I. tricolor

S

vine

Pu P B R V W  

Nasturtium  

Tropaeolum majus

S  

12- climber

0 R Y W  

Cup flower  

Nierembergia

Sh  

6 - 9

Pu W

Pansy  

Viola wittrockiana aka. v. hortensis

S,LSh  

4-8  

PuWBRPV

Shirley Poppy Papaver rhoeas S 24 -48 self sows
Poppy Papaver somniferum S LSh 24-48 R Lav W

Petunia  

Petunia hybrida

LSh

8 - 15

W R B L Pu P  

Moss Rose

Portulaca  

S     

6-8

WRPLYO

Snapdragon  

Antirrhinum majus

S,LSh  

6 -48  

RPYOBrL

Statice  

Limonium sinnuatum

S  

18-24

RBYWP

Stock

Matthiola incana

S,LSh

12-30

WBPYPu  

Strawflower  

Helichrysum bracteatum

S

18-36

YORWP

Sweet alyssum  

Lobularia maritima

LSh

4 - 8

Pu W P L  

Sweet Sultan Centaurea moschata S -24"

L, Ro.W Y

Verbena  

Verbena hortensis v. hybrida

S

8-12

RBWPPu

Zinnia  

Zinnia elegans, Z. haageana

S

10-36

RPWVYGO

Zinnia Angustifolia S 6-12 Go O W

(Very similar charts to this appear in the 2002 Master Gardener Manual which were prepared by Carol Adams. However, since we do not have access to the CD for that manual and in fact had no knowledge of those chart's existence or contents, the charts for Annuals, Bulbs, and Perennials were independently prepared for this web site by Ellen Reed (author) and Ruth Bronson (editor) from materials in the 2001 Manual.)

B = Blue; Br = Bronze; G = Green; Go = Gold; L = Lavender; 0 = Orange; P = Pink; Pu = Purple;
R = Red; W = White; Y= Yellow

02/05/2003

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