Geranium plants are beloved by garden enthusiasts all over the world. Their stunning bright colors and easy-to-grow nature make them a popular houseplant and outdoor variety. Put them in large pots to enhance your front entrance or spread them along a walkway. Wherever you plant them, geraniums will not disappoint.
What is a Geranium?
The plant most of us think of as a geranium is not a true geranium. According to the plant experts at Costa Farms, the annual geraniums that go by that name are part of the pelargonium family and a native of South Africa. True perennial geraniums also go by the name Cranesbill. These are not as common as the annual varieties of pelargonium.
Most gardeners grow the pelargonium as annuals, though they will survive as perennials in certain warm climates. Even if you grow these plants as outdoor annuals, they can overwinter inside. Keep them inside during the coldest parts of the year and then bring them outside again in the spring.
Annual Geranium Quick Facts
|Light||Full sun for some varieties, others tolerate partial shade|
|Water||Water on a regular basis during the growing season, but taper during dormancy inside|
|Fertilizer||All purpose plant food every 4-6 weeks during spring and summer|
|Pests||Thrips, budworm, mealybugs, spider mites, caterpillars, aphids, slugs|
|Diseases||Gray mold, mildew|
|Soil||Well-drained soil that is neutral for most varieties|
|Climate Zones||Hardy in Zones 10-11|
|Size||Vary in size according to type from 5 inches to 4 feet|
|Foliage||Ruffled leaves that are green with specialized varieties that are gold, chartreuse, bronze, and red.|
|Toxicity||Annual geraniums are toxic for cats and dogs|
|Flowers||Red, white, pink, orange, purple, and mauve|
There are six common varieties of annual geranium plants.
- Zonal geraniums – Tight mounding and upright flowers with scalloped leaves that feature dark arcs/stripes
- Ivy geraniums – Cascading growth pattern with ivy shaped leaves
- Interspecific geraniums – A cross between zonal and ivy geraniums with the prized qualities of both varieties
- Regal geraniums – Cool season annual with majestic bi-colored blooms
- Scented geraniums – Leaves of the scented geranium varieties have rose, lemon, citronella, nutmeg, apple, and oak. Flowers are less lush on these varieties
- Angel geraniums – A cross between regal and scented geraniums. Range in size from dwarf to larger varieties
Geranium Care Guide
The care of geranium plants is easy, but they offer an outsized impact for hanging baskets, standing containers, and outdoor garden borders.
Geranium varieties love the sun. They should receive at least 6 hours of full sun per day to encourage the most blooms. In hot climates, geraniums prefer some afternoon shade during the hottest parts of the day. Zonal varieties will do fine with some shade. Regal varieties do better if some shade is provided.
Because they can spend their days in the hot sun, geraniums require good waterings. Water these plants when the top of the soil in the ground or pot begins to feel dry.
Each time you water, allow the water to penetrate to the bottom of the plant, but water should not be allowed to sit on the roots. If this occurs, the geraniums can experience root rot. Make sure that water can run through the soil where the geraniums are planted either in the ground or in a pot with good drainage holes.
Geraniums prefer well-draining soil that is neutral to acidic. If your soil is too heavy, add peat, compost, or perlite to lighten it. Most geraniums varieties prefer a pH of 6.5, while some like Ivy and Regals prefer a pH of 5.3 – 6.
The University of Massachusetts Amherst Center for Agriculture also recommends soilless mixtures as they give the growers more flexibility in controlling the physical and chemical properties of the medium. Make this transition after experimenting on a small scale as it takes time to get used to the lightweight mixtures and their rapid drying time.
Most gardeners grow outdoor geraniums as annuals and bring them indoors to overwinter inside. When you plant geraniums outside, make sure temperatures are averaging around 75 degrees Fahrenheit during the day and 60 degrees Fahrenheit at night. This is for optimum growth.
When temperatures dip below 50 degrees or above 85 degrees growth is stunted. Some varieties will exhibit heat or low temperature stress with discolored leaves or a decrease in plant growth.
Geraniums require some fertilization to thrive, but too much fertilization will increase the foliage but decrease geranium flowers. Use an all purpose water soluble plant food in combination with thorough waterings. Mix 2 tablespoons of an all-purpose solution with a gallon of water. Feed every 4-6 weeks during the high growing season and taper if you are overwintering your geraniums.
Pests and Diseases
There are several common geranium diseases that are associated with crowding and overwatering. Watch for discolored and shedding leaves. Remove infected plants. Also, make sure to not overwater as it can cause root rot and mildew.
A standard insecticide will help mitigate common geranium pests like aphids, cankerworms, spider mites, scales, and slugs.
When you overwinter your plants inside, look out for spider mites. You may notice dry leaves, tiny webbing, or white specks on your plants. Treat an infestation of spider mites with horticultural oil like neem oil.
Geraniums are one of the best plants to propagate from stem cuttings. Cut a stem just below a node and use a stem that is around 4-6 inches long. Strip the lower leaves and put the cutting in potting soil. Place in an area with bright but indirect light. Water when the soil on the top becomes dry to the touch. You can also place the stem in just water. Roots will begin to develop in around 4 weeks.
In order to plant these young geraniums outdoors, allow the immature plants one week acclimating them to the outdoor conditions. Bring the young plants outdoors to a sheltered location for several hours each day. At the end of the week, you can plant them outdoors during the spring or early summer.
Geraniums do not require much pruning. Just make sure to pick off a spent geranium flower just like you should for petunias to allow more reblooming. You can also pinch back any leggy growth to ensure a more compact plant.
Annual Geranium Varieties for Home Use
We have gathered some stunning geranium varieties that work for most home garden spaces.
‘Calliope Dark Red’
This is a common dark red geranium variety that is a cross between an ivy and zonal geranium. It is a vigorous grower with deep red flowers and zonal colored leaves. It has a mounding and semi-trailing growth pattern.
This is an ivy geranium variety with medium pink flowers and a trailing growth habit. It works well in hanging baskets and containers.
This is a scented geranium with leaves that have a fragrance like lemons. It has petite lavender flowers.
This is a lovely angel geranium with white flowers and a distinctive red feathering pattern. This delicate plant has a compact growth pattern.
‘Americana Cherry Rose’
This is a zonal geranium with bright pink flowers that grow upright and dense. In hot climates, this geranium grows best with some partial shade.
This regal variety has a deep red geranium flower that is small and compact. The plant grows just 12 inches tall and perfect for container or delicate border edging.
Frequently Asked Questions (FAQ)FAQ
What are the best pots for geraniums?
Geraniums look gorgeous in different styles and sizes of containers. In general, choose a pot that is at least 12 inches tall with good drainage holes. If you are mounding geraniums or are using an ivy geranium, use a taller pot with a larger circumference.
Where can I find geraniums for sale?
Common annual geraniums are available at most home improvement stores and local nurseries. If you want more specific varieties look for nurseries that sell online. Make sure that the geraniums are zoned for your location before you purchase them.
Are rose geranium leaves edible?
Rose geraniums are a variety of scented geranium that is used in kitchen concoctions from food to scented oil. Use washed and pesticide free leaves to flavor sugar, cakes, cookies, summer drinks, simple syrup, and ice cream.
Can I make geranium oil?
Scented geranium oil is popular as a beauty aid. Use fragrant geranium leaves to make your own oil. Take pesticide free scented geranium leaves and put them in a jar filled with sesame or olive oil. Make sure the leaves are covered by the oil. Place the jar in a warm and sunny location for one week. Strain the old leaves and add new leaves to the oil. Repeat this process for 5 weeks. Store the oil away from bright sunlight. Be sure to monitor your skin after you apply geranium oil. It is safe for most people, but it may cause others irritations like a rash.
Geraniums are beautiful plants that are easy to grow and have versatile applications. Use them to create a stunning front door display or lush hanging baskets.
You can also use scented varieties in cooking and to make beauty oil that has anti-inflammatory and antibacterial properties. Whatever your objective, geraniums will repay your investments in them with beauty all summer long.