Seed geraniums and zonal geraniums are two types of geraniums that are often confused. They belong to the same genus and are closely related but have contrasting characteristics, such as size, shape, growth rate, and preferred temperature. Still, they are pretty easy plants to tell apart once you learn the differences. So let’s discover everything you need to know about seed geraniums vs. zonal geraniums!
Comparing Seed Geranium vs. Zonal Geranium
|Characteristic||Seed Geranium||Zonal Geranium|
|Propagation Method||From seed||From cuttings|
|Soil requirements||Well-drained soil with a lot of organic matter. No manure. Fertilize while in bloom.||Well-drained soil with a lot of organic matter. No manure. Fertilize while in bloom.|
|USDA Hardiness zone||Zone 3-9||Zone 10-11|
|Preferred temperature||40-50 degrees Fahrenheit||50-75 degrees Fahrenheit|
|Flower care||Naturally sheds old blooms||Must be manually de-headed|
|Size||10-15 inches tall||24 inches tall|
|Leaf description||Round-kidney-shaped leaves with a few purple, bronze, or dark green markings||Round-kidney-shaped leaves with many purple, bronze, or dark green markings.|
|Flower description||Single petal flowers. 3-4 inch blooms||Double petal flowers. 6-inch blooms|
|Flower colors||Pink, red, orange, salmon, violet, white, bicolor||Red, pink, salmon, white, cherry, rose, bicolor|
The 4 Key Differences Between Seed Geraniums and Zonal Geraniums
The main difference between seed geraniums and zonal geraniums is their size. Zonal geraniums are much taller than seed geraniums, reaching 24 inches tall, compared to only 15 inches for seed geraniums. Other differences between these two plants include how they are propagated and how much care they need. Seed geraniums are propagated from seed while zonal geraniums are propagated by cuttings.
Seed geraniums naturally shed old blooms while zonal geraniums need to be manually de-headed to promote further flowering. They also have different cold tolerances.
Seed Geranium vs. Zonal Geranium: Propagation
The main difference between these two closely related plants is the propagation method. You get more plants from a seed geranium by waiting for them to go through their life cycle. After they flower, they will set seeds, generating more plants.
The zonal geranium does not produce seeds at all. The zonal geranium is propagated solely by tissue cuttings. It is also the more common of the two. It has been propagated prolifically in nurseries to produce taller plants that grow faster and produce new flower colors.
Seed Geranium vs. Zonal Geranium: Size and Shape
Another difference between the two geraniums is their size. The seed geranium has kept its original compact shape and reaches an ultimate height of 10 to 15 inches. It is an ideal choice for a small container garden that needs a splash of summer color. The benefit to growing them in containers is that you can take them indoors over winter if you live in a climate with temperatures below 40 degrees Fahrenheit in winter.
The zonal geranium has been bred selectively in nurseries to reach a height of 24 inches. It also has a more sprawling shape and is less compact than the seed geranium. It is often planted in beds and borders and grown as an annual plant. However, it will live for up to 40 years if you have very mild winters that never go below 50 degrees Fahrenheit.
Seed Geranium vs. Zonal Geranium: Plant Care
Another consideration when choosing the right geranium for your garden is the upkeep. Soil requirements for the two geraniums are identical – they are both happy in well-drained soil with a lot of organic matter. They have a strong dislike for manure of any kind. They both prefer a sunny spot with 4 to 6 hours of sun per day.
The main difference in plant care comes after bloom time. The seed geranium naturally drops its old flowers in a process known as petal-shattering. Each petal falls off the plant, leaving only a bare stamen behind. This behavior is beneficial because new blooms automatically follow right away. The only downside is the mess the dropping petals leave on your porch or patio.
The zonal geranium will keep the entire flower intact, and it will wilt and brown on the plant. To encourage new blooms, you must manually dead-head the old flowers by removing the entire flower stalk where it meets the main stem. This behavior is beneficial because the plant remains tidy, as will your porch or patio. The only negative is that you have to pay attention. If you forget to de-head it, the plant will only give you one cycle of blooms.
Seed Geranium vs. Zonal Geranium: Climate
Another critical difference is the climate requirement. The seed geranium is a hardier plant growing in USDA zones 3 to 9, which have a low winter temperature of 35 degrees. However, seed geraniums strongly prefer 40 degrees as a low temperature.
The zonal geranium is a tender perennial and cannot withstand temperatures below 50 degrees in the winter. It is most often grown as a summer annual for this reason.
Both varieties of geranium are commonly brought inside and grown as houseplants. They adapt very well to a bright sunny window in the winter. They will thrive and flower under plant-specific grow lights.
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