For spring flowering plants, geranium seeds should be sown in early- to mid-February.
For many years, geraniums have been a common choice for bedding plants. Cuttings are a frequent way to grow plants. Geraniums can, however, also be raised from seeds. Hybrid geraniums that are grown from seeds have great vigor, heat tolerance, disease resistance, and free blooming.
Growing geraniums from seeds is not too difficult. Geranium seedlings, however, develop slowly. For spring flowering plants, geranium seeds should be sown in early- to mid-February. Approximately 13 to 15 weeks after seeding, flowers begin to bloom. Geraniums from the Elite, Orbit, Maverick, and Multibloom Series are recommended for Iowa. A series is a collection of closely related types that share similar traits like height, spread, and flowering behavior. The only trait that typically varies within a series is the color of the flowers.
Jiffy Mix and Redi-earth are two great soilless mixtures that work well as germination media. Geranium seedling damping-off can be a significant issue during germination. Different species of fungi attack the seedlings and kill them, which is what causes damping-off. Containers used to start seeds should be spotless and have sufficient drainage to deter this. Prior to disinfection, previously used containers should be cleaned in soapy water and dipped into a solution of one part chlorine bleach to nine parts water.
The germination media should be poured into the container to within 1/2 to 1 inch of the top. Lightly firm the medium, completely wet it, and then give it some time to drain. Rows of seeds should be 2 to 3 inches apart, and the medium should cover the seeds by about 1/8 inch. After planting, thoroughly hydrate the soil by immersing the container in water only partially. Remove the container from the water after the surface is damp, then let it drain. The media can alternatively be hydrated with a gentle water spray from a sprinkler made of a rubber bulb or a similar tool.
Use clear plastic food wrap or a clear plastic dome to cover the container to maintain a constant moisture level during the germination process. Place the container in a well-lit area away from the sun. If the covered container is placed in the direct sun, there could be an excessive accumulation of heat. When germination is taking place, the medium’s temperature should be between 70 and 75 degrees F. The seeds should start to sprout in seven to ten days at the right temperature and moisture content.
As soon as the seeds start to germinate, remove the plastic covering. Put the seedlings in a window with natural light or under a light fixture. Fluorescent lights should be turned on for 12 to 16 hours a day and placed no higher than 4 to 6 inches above the seedlings. When the seedlings develop their first true set of leaves, transplant them into separate containers using a well-drained commercial potting mix. Handle the little seedlings by their leaves since the fragile, delicate stems are easy to break. When transplanting, place seedlings at the base of the seed leaves (cotyledons).
Grow seedlings under fluorescent lights for the greatest outcomes. One 40-watt cool white and one 40-watt warm white fluorescent tube can be used in a conventional fluorescent shop light. Due to little light, plants grown in windows frequently grow tall and spindly. Geraniums prefer daytime temperatures of 70 to 75 degrees and nighttime temperatures of 60 to 65 degrees. When the soil surface is completely dry to the touch, water the geraniums thoroughly. Fertilization is probably not required if using a potting mix that is sold commercially and has a slow-release fertilizer. For potting mixes without a slow-release fertilizer, applying a diluted fertilizer solution once every two weeks should be adequate.
Before putting the plants in the garden, harden or acclimatize them to the outdoors for seven to 10 days. First, plant the geraniums in a sheltered, shaded area. Then progressively subject the plants to extended sun exposure times. When there is no longer a chance of a frost, plant the geraniums outside. Early May is typically a good time to grow geraniums outside in central Iowa.
When do geraniums need to start growing?
In the summer, give geraniums plenty of water and deadhead to promote a second rush of blooms.
Annual geraniums are frequently grown, and at the conclusion of the summer, they are composted. Keeping them over the winter is worth considering if you have space and a spot that doesn’t get frosty.
Lift plants that are in garden soil or big pots and place them in a smaller container to overwinter geraniums. Ideally, you should do this before the first frost. Damaged leaves and wilted blooms should be removed. Plants should be pruned back by about a third and placed in a bright, frost-free area. Because the plants won’t completely hibernate, water sparingly all winter long. Apply a general liquid feed in the spring and increase watering. Plant just until all threat of frost has passed, typically starting in late May.
Geraniums can continue to bloom throughout the fall or even into the winter if grown as indoor plants. Indoor geraniums should not be placed near open flames or radiators.
Here, Monty Don demonstrates how to give wintering geraniums a new lease of life by severely pruning them before they begin to grow:
How to propagate geraniums
In the spring, trim fresh growth from plants that overwintered. If you’d like, cuttings can be taken in the late summer.
Cut above the third joint below the developing tip to eliminate cutting material. Pinch out any buds that are producing flowers. Remove all leaves except for the top two with a clean knife. Recut the cutting’s base at the lowest joint.
Compost that has been cut up should be placed in a plastic garden container and compacted. Water the cuttings, then place them about one centimeter into the compost. Place the pots in a well-lit area that is warm but not hot. If you’ve obtained cuttings from many different types, remember to name the pot.
In our No Fuss Guide, Rosie Yeomans demonstrates how to propagate pelargoniums.
Growing geraniums: problem solving
Pelargonium rust can harm zonal geraniums. This is a fungal disease that frequently gets worse in humid summers or after plants have been grown in an area with inadequate ventilation. Brown patches on the underside of leaves are a sure sign of rust. Plants with brown patches should be destroyed.
In this Quick Tips video, we explain if you should water geraniums over the winter:
Hardy Geraniums vs. Pelargoniums
Pelargoniums should not be confused with hardy geraniums. You might be wondering what makes a geranium different from a pelargonium. Similar to some siblings, they are both members of the same plant family, but they could not be more unlike.
Pelargoniums cannot withstand frost, while hardy geraniums can. Pelargoniums are usually treated as annuals and replanted each year, but true hardy geraniums are perennials that grow back every year. Pelargoniums die in the winter.
Prune your Hardy Geraniums
Your sturdy geraniums will look their best and promote new growth if you prune them properly. By correctly pruning your hardy geraniums after the blooming season, you can encourage repeat blooming. The majority of geraniums can be cut back twice in a single season, which allows them to bloom at least three times.
When to Prune
Your hardy geraniums should be pruned in accordance with the season you are in. Rozanne will require various cuts in the spring, summer, and fall. To maintain your blooms rich and healthy, mark your calendar and adhere to our seasonal trimming recommendations.
What tools you need
Your geraniums may be pruned fairly easily. All you’ll need is the ability to prune, a pair of sharp pruners, your favorite mulch, and your favorite gardening gloves. Watch this video to learn more about pruning strategies in detail.
How to prune
You shouldn’t be concerned that pruning your flower’s back will harm her. The majority of hardy geraniums require trimming to promote new growth and prevent them from encroaching upon other plants.
Trim the plant back to within a few inches of the ground or to about an inch above the main stem once the flowering is completed or you find old growth. Remove any brown stems or yellow leaves after that by going inside.
Soon after trimming, more leaves will start to appear. Some resilient geraniums even have the ability to blossom again. Maintaining correct pruning on your plants encourages new development and keeps them from spilling out throughout your landscape.
What pruning advice do you prefer? Share them with us in a comment on our Facebook page!
When do geraniums bloom?
Pelargoniums, also referred to as “geraniums,” are decorative perennial plants that bloom for months on end with a profusion of vibrantly colored flowers. Some plants begin to bloom in the spring, but most do so from early June until the first hard frosts of the fall. They can bloom all year long if they are grown inside.
Because pelargoniums are not cold and frost hardy, they shouldn’t be confused with perennial plants that are cultivated outside all year round, such as cranesbill or the closely related true hardy geranium.
In addition to inside, in conservatories, and in greenhouses, pelargoniums are utilized to create vibrant displays in beds and borders, hanging baskets, and various containers. Pelargoniums have their own national society because of their widespread popularity. Local organizations like The Pelargonium & Geranium Society are also mentioned.
Cultivation
Pelargoniums should be taken indoors into a sheltered habitat in the fall because while they can usually withstand heat, drought, and strong frosts, they cannot. If kept at a temperature of at least 10-13C (50-55F), they can bloom all year.
The great majority of pelargoniums require full sun, or at the absolute least, excellent light.
While zonal pelargoniums may take some light shade, regal pelargoniums prefer light shade.
They require a healthy, moist, yet well-drained soil in order to flower extensively. Use an excellent multipurpose compost or one with extra John Innes for growing in pots.
Pelargonium varieties
Pelargoniums come in six basic types, with additional subtypes for some of them:
- Zonal pelargoniums: These are the bushy, upright ‘bedding’ pelargoniums that are cultivated outdoors in pots or in beds and borders and have enormous, single or double flowers. The term “Zonal” describes the leaf markings, many of which are very elegant and ornamental.
- Pelargoniums with ivy leaves: These are the trailing types, with fleshy leaves and single or double flowers in a variety of colors, used in hanging baskets or as container edges.
- Regal pelargoniums: These grow taller, bushier plants with single, infrequently double, flowers that are typically pink, purple, or white. Typically, they are raised outside in pots or for interior displays.
- Angel pelargoniums are smaller, more compact, and bushier than regal pelargoniums.
- Pelargoniums with scented leaves: As their name suggests, these plants are mostly planted for their intensely fragrant leaves, however they also produce pretty little solitary flowers. The leaves could also be distinctively lobed or toothed, variegated, or both.
- All additional pelargoniums that don’t fit into any other category are considered unique pelargoniums.
Pelargoniums are a specialty of various nurseries. Visit their websites to view the extensive selection, which includes photographs to assist you in deciding which ones to purchase:
Do geraniums bloom year-round?
Amazingly, annual geraniums (Pelargonium hybrids) thrive and flower wonderfully from spring till frost with little effort. The next spring, these resilient tiny plants will take off and grow once more if you dig them out in the fall and store them in a cardboard box or paper bag for the winter. Learn how to preserve your geraniums over the winter so you can enjoy them year after year by watching our video and reading the article below.
How can you revive dead geraniums?
Geraniums have the advantage of easily entering dormancy, allowing for storage in a manner akin to that of sensitive bulbs. This method of storing geraniums for the winter entails digging the plant up in the fall and carefully removing the soil from the roots. The roots should not be spotless, just clear of dirt clumps.
In a room with a constant temperature of roughly 50 degrees Fahrenheit, such as your garage or basement, hang the plants upside down (10 C.). Rehang the geranium plant after soaking the roots in water for an hour once a month. All of the leaves on the geranium will fall off, but the stems will still be alive. Replant the dormant geraniums in the ground in the spring, and they will come to life.
How cold can geraniums tolerate it?
Grow geraniums as indoor houseplants or annuals outside their hardiness area. Geraniums can endure cooler temperatures and even light frosts, but when temperatures dip below 20 degrees Fahrenheit, they are subject to harsh lethal freezes, which can cause freeze damage and even lead to plant death. The minimum temperature for geraniums in Celsius is -7 degrees.