Growing Annual Geraniums

Annual geraniums are popular indoor and outdoor flowering plants.  The variety of flower colors, leaf shapes, colors, and growth habits make this plant ideally suited for home landscapes.  These versatile plants are excellent as annual bedding plants, in hanging baskets, and in containers.  Annual geraniums are not actually "true" geraniums as they are members of the genus Pelargonium. True geraniums are perennials in the genus Geranium.

Types  |  Care  |  Overwintering  |  Growing from Seed  |  Pests & Diseases  |  More Information

Types of Annual Geraniums

Zonal Geraniums

Variegated Garanium
Common or Zonal Geranium

Common garden or zonal geraniums (Geranium x hortulanum) are widely sold as bedding or container plants.  Many have distinct, dark markings or bands (sometimes called zones) on their leaves.  Flowers are borne in large, showy clusters and may be single or double.  Flower colors include red, burgundy, lavender, pink, salmon, orange, white, and bicolor.  

Fancy-leaf or variegated geraniums are becoming popular in some areas of the US.  They are selections of hybrids from the common or zonal group of geraniums noted for their distinctive, multi-colored foliage. Combinations of green, yellow, white, red, burgundy, bronze, or coral leaves make these attractive plants for both indoor and outdoor containers. Some have scented foliage.  Plants have red, pink, lavender, or white flowers but are smaller and less showy than the common garden geraniums.

Ivy Geraniums

Ivy geraniums (Geranium peltatum) have ivy-shaped leaves and more vine-like or trailing growth habit.  Flowers can be single or double and are available in colors similar to the common garden geranium. Plants perform well in hanging baskets and window boxes. Ivy geraniums are somewhat less heat tolerant than common garden geraniums and benefit from some afternoon shade.

Scented Geranium
Ivy Geranium

Scented Geraniums

Scented geraniums consist of several species, selections, and Pelargonium hybrids.  Plants have a wide range of leaf sizes, shapes, and colors.  Leaves are normally scented (hence the name) with lemon, rose, peppermint, nutmeg, apple, oak, and other fragrances.  Scented geraniums are excellent container houseplants. Flowers are normally white, pink, or lavender and are typically less showy than most other geraniums.  The widely promoted "mosquito geranium" is a type of scented geranium.  When the leaves are rubbed, brushed, or crushed, a citronella fragrance is released.  Since the citronella oils are only released when touched, plants growing in containers on a patio or deck do not repel mosquitoes.

Martha Washington Geraniums 

Martha Washington Geranium

Martha Washington or regal geraniums (Pelargonium x domesticum) are the cool-season annual geranium.  This group is noted for its large, ruffled flowers in white, pink, red, purple, yellow, burgundy, and bicolors. Since these geraniums thrive in cooler temperatures, they are normally only sold as container plants in late winter or early spring.  While they make wonderful houseplants for several weeks, they are typically discarded when flowering is complete.

Geranium Culture

Planting Time & Location

Annual geraniums should be planted outdoors after the danger of frost has passed.  This is generally mid-to-late May in much of Iowa.  Most geraniums prefer moist, fertile, well-drained soils and full sun (at least 6 hours of direct sun per day). Flowering will be reduced in areas with less than 6 hours of sun.

Annual geraniums also do well in containers.

Water & Fertilization

Geraniums growing in containers require frequent watering, as often as two or three times a week in hot, dry weather. Geraniums in ground beds and borders require approximately one inch of rain per week.  For best performance, water once a week during dry periods. When watering, avoid wetting the foliage as this may promote disease development. 

Almost all geraniums benefit from regular fertilizer, especially those in containers. Prior to planting in the garden, apply and incorporate 1 to 2 pounds of all-purpose garden fertilizer, such as 10-10-10, per 100 square feet of garden area.   A dilute solution of a water-soluble fertilizer applied once or twice a month during the summer is ideal.  Geraniums growing in containers should be fertilized every 2 to 4 weeks with a dilute fertilizer solution.

Encouraging More Flowers

Geraniums benefit from regular deadheading (removal of spent blooms).  Deadheading promotes the production of additional flowers by preventing seed formation. It also improves overall plant appearance.

Overwintering Options

The first hard frost will destroy geraniums growing outdoors. However, it is possible to overwinter geraniums indoors. Before frost, pot up individual plants, take cuttings, or store bare-root plants in a cool, dry place. For all methods, select only plants that are healthy and disease-free.

Potted plants

Carefully dig up each plant and place it in a large pot. Prune the geraniums back by one-third to one-half, then water each plant thoroughly. Place the geraniums in a bright, sunny window or under supplemental lights. Geraniums prefer cool indoor temperatures. Daytime temperatures of 65° to 70°F and night temperatures of 60° to 65°F are ideal. (Geraniums become tall and spindly when grown in warm, poorly lit areas.) While indoors, water the plants thoroughly when the soil becomes dry. Occasionally pinch geraniums to produce stocky, well-branched plants.


Geraniums can be successfully rooted from cuttings over winter. This approach works well when plants are not in containers or there is not sufficient room indoors for large plants.  Learn about taking geraniums from cuttings and keeping them over winter in this article: How to Propagate Annuals from Cuttings.

Common geraniums on the Iowa State University campus.

Bare Root Plants

Lift plants from ground beds or containers in fall before the first frost, gently shake the soil from the plant's roots, and place the bare-root plants in a large paper, grocery bag. Store the geraniums in a dark, cool (45° to 55°F), and dry location for most of the winter. An unheated bedroom or indoor porch might be a suitable storage location. An alternate method is to hang the plants upside down in a cool, dry location. In mid-March, remove the dead stem tips (cut back to firm, green stem tissue) and plant what is left in containers.  Place containers in a sunny window or under supplemental lights and water as needed. Plants can be planted outside in May.

Growing Geraniums from Seed

Many gardeners purchase geranium plants from garden centers and greenhouses.  However, geraniums can also be grown from seeds.  Seed-grown hybrid geraniums possess excellent vigor, heat tolerance, disease resistance, and are free-blooming. 

Learn more in this article: How to Grow Geraniums from Seed.

Pests & Diseases

Like all plants, geraniums have their share of disease and insect problems.

Bacterial leaf spot is caused by the bacterium Xanthomonas pelargonii and is especially prevalent in warm, wet weather where plants are grown in crowded conditions. Disease symptoms include small (pinhead size), circular or irregular, brown, sunken spots on older or lower leaves. Large numbers of spots will occur on a single leaf; these will coalesce, killing a large portion of the leaf, which will then drop off. As the disease moves through the plant, the lower leaves wilt and yellow. In severe cases, the stem will possess black stem cankers, killing the upper portion of the stem. Leaves infected with bacterial leaf spot should be removed as soon as it is noticed. Severely infected plants should be removed. There is no chemical cure for bacterial leaf spot. Make sure and destroy infected plants and plant parts this fall.

Another common disease of geranium is a fungal disease known as gray mold, botrytis leaf spot, or botrytis blossom blight. It is caused by Botrytis cinerea. Botrytis is favored under cool, moist conditions or where plants are watered frequently. Leaves develop zonate, brown leaf lesions which develop a grayish brown mass of fungal spores. The lower leaves will yellow and rot. Flowers may also become infected. They show discolored petals which wilt and fall. Remove affected leaves and flowers. Fungicide sprays, when environmental conditions are favorable, will help reduce levels of this disease. Rust, root rot, stem rot, and leaf spots are other diseases known to infect geraniums.

Insects that frequently attack geraniums include aphids, cabbage loopers, geranium budworm (aka tobacco budworm), and fall cankerworms. The four-lined plant bug, scale, and slugs can also cause damage. To control for insect issues, start by correctly identifying the insect pest.  A combination of cultural controls (like handpicking) and insecticides can potentially be used for management. 

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Last reviewed:
March 2024