Summer Flowering Annuals (Angelonia, Euphorbia Diamond Frost, & Annual Vinca)

by Millie Davenport, Horticulture Extension Agent, Home & Garden Information Center, Clemson University, 2009



Hi, I am Millie Davenport, a horticulture extension agent with the Clemson University Home and Garden Information Center.

Today we’re looking at Summer Flowering Annuals.

We are here at the South Carolina Botanical Gardens outside the Fran Hanson Discovery Center and we are going to look at a few summer flowering annuals. Your summer flowering annuals are warm season plants that perform really well throughout the summer months and then they are going to die back with the first frost or freeze that comes along in the fall. Summer flowering annuals are a great way to add lots of flower power to your landscape. This is Angelonia angustifolia, also known as Summer Snapdragon. It is in the Snapdragon family, Scrophulariaceae. It has these really nice tall spikes of flower blossoms that are similar to our traditional Snapdragon. Most of your Angelonia’s are reproduced by cuttings, this particular variety is by seed. So, it is one of the first from seed. Its name is Serena. It is a mix, it has different colors and has a really nice mounded growth habit to it. The one’s that are usually reproduced by cuttings can get up to 24 inches tall. This particular variety only gets 10 to 12 inches tall. Whether you are choosing the Angelonia varieties reproduced by cuttings or the seed variety like Serena they all have interesting colors, like purples, the whites, or even the pink colors that are available, some are even bi-colored. This is a mix, so you will get a mixture of all the different colors in it. All of them are going to do well in a full sun location with well- drained soil. And, each of them as well will be heat and drought tolerant in your landscape. They are going to do well and give you lots of flower display throughout the summer months.

This is Euphorbia Diamond Frost. This is a great little airy textured, delicate kind of plant. There are lots of little delicate, small flowers on this plant. It has a really nice mounded habit to it, reaches about 12 to 18 inches tall. And the great thing about this little plant is that it great at softening up other plants in your landscape. To me, at first glance, it give the feeling of baby’s breath or gypsophila, a really soft texture. However, the difference with the baby’s breath and the Euphorbia is that with Euphorbia Diamond Frost, it is actually going to do well in the heat and drought that we can experience here during the summers here in South Carolina. So, this is a great addition to your landscape. It is going to do well alone, like you see it here. Or, if you want to mix it up with other plants in a mixed container, it will look really nice to add some color and texture to that container.

This is Vinca, Catharanthus roseus, also known as Madagascar Periwinkle. It is another great flowering annual with a lot of flower power during the summer months. The annual Vinca is really heat and drought tolerant. It is so important that you have a well-drained soil for this particular plant, if you don’t then it does run the risk of some root rot problems. So, you definitely want to run this plant more on the dry side than the wet side. That is really crucial to have a healthy plant, and that is why it does so well in drought stricken area. Annual Vinca is available with a trailing habit or a mounded habit, like you see here, depending on what variety you choose. This particular variety we are looking at is First Kiss Blueberry. This particular variety of Vinca is only going to reach about 8 to 10 inches tall, it has a really nice mounded habit for the landscape, and a really unique blue colored flowers, which is where that blueberry name comes from. Annual Vinca is available in various different colors, you will find them available in white, apricot, reds, purples, and pinks, and even the blue that you see here. So, there is a wide variety of colors that you could use to add to your landscape.

With a full sun location and well-drained soil, all of these flowering plants will do well in your garden, they are going to give you a heat and drought tolerant selection for the landscape.

For more information on gardening, landscaping, insect and disease problems on your plants, visit the Home & Garden Information Center web site at www.clemson.edu/hgic.

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