Hydrangeas are certainly among the most popular plants in gardens all over the world! Moreover, they have been called the America’s favorite flowering shrub and you’ll find them on most top lists of flowering shrubs, like this one on Dengarden. They come in various colors, ranging from white to dark purple.
However, hydrangeas with crimson red flowers are certainly the ones that stand out. In this article, will tell you everything you need to know in order to find and successfully grow red hydrangeas.
What Are They?
The old-fashioned charm of these flowers is always mesmerizing. Moreover, these shrubs are also very easy to grow and to care for. According to the Farmer’s Almanac website, hydrangeas can tolerate almost any soil. For these reasons, the growing popularity of these shrubs in gardens shouldn’t come as a surprise.
The word hydrangea is actually the name of a genus that contains about 100 species of flowering shrubs. The luscious flowers appear in dome-like bunches at the top of the stems. Some varieties start flowering in the early spring, but with some species, the flowering can last until the late fall.
How to Choose and Plant Hydrangeas
According to SFGate, only five species of hydrangea are commonly grown in the United States. Among these five species, only three have red varieties. Probably the most common is the bigleaf hydrangea. Its Latin name is H. macrophylla. This sort gets its name from it’s large, broad leaves, but the plant itself is also usually quite large. According to SFGate, the average height and width of this sort of bigleaf hydrangea is 10 feet. The plants from this species usually start blooming in late spring.
The second species that comes in red varieties is the panicle hydrangea, also known as H. paniculata. The flower clusters on these plants are longer and shaped more like a pyramid than like a dome, which is the case with other types of hydrangea. According to Fine Gardening, this species tolerates cold much better than its cousins.
Finally, there is the oakleaf hydrangea, also known as H. quercifolia. With this sort, you won’t actually get red flowers, but its leaves turn decidedly red during the fall. This species usually reaches the height and width of 8 feet.
— Graciela De Luca (@gradeluca27) March 19, 2015
Bumblebee basking in the Limelight Panicle Hydrangea. pic.twitter.com/q7Qef7HJmG
— Caroline Petti (@pettiplease) October 27, 2019
— Jan Johnsen (@janjohnsen23) June 26, 2017
Other Popular Non-Red Options
Love my Hydrangea macrophylla ‘Zorro’ – beautiful lacecap with stunning black stems 🌿 pic.twitter.com/JdpDSMgUAR
— Brigitte @ In The Green (@InTheGreen2) June 29, 2018
— 珠璃 ＊･｡ﾟ♬*゜ (@heliostitanes) June 23, 2016
The best climbing hydrangea I’ve ever seen pic.twitter.com/8Zc20u6CsA
— karen gimson (@kgimson) June 25, 2015
Red Hydrangea Varieties
The majority of red varieties comes from the family of bigleaf or French hydrangeas. DIY Network has an article listing some of the most popular red varieties from this species. They recommend the Royal Red and Lady in Red varieties of hydrangea for adding a shot of crimson to your garden. The Lady in Red variety also has red stems that add to the scarlet sensation, but the color of the flowers can range from light pink to dark crimson.
Concept Plants also recommends Red Sensation, a stunning variety of H. macrophylla. This variety is much smaller than other varieties from this family, which makes it perfect for balconies or other smaller spaces. It usually grows no higher than 35 inches. Another red variety is Ami Pasquier, recommended by Southern Living.
When it comes to panicle hydrangeas, Fire and Ice is a really interesting variety. It starts with pale green flowers in early summer which gradually turn to dark red as autumn approaches. As we have already mentioned, oakleaf hydrangeas don’t really come with red flowers, but their leaves can turn red in the autumn. The color of the leaves can be quite vibrant which makes it a nice addition to autumn gardens.
Hydrangeas come in a range of colors. White flowers are the most common, but they also come in colors ranging from green, over blue, violet, and purple, to dark red. However, many hydrangea varieties also have a rare ability to change the color to a certain degree.
The reason for this is the fact that these plants accumulate aluminum from the soil.
According to Garden Therapy, acidic soil makes the flowers blue. If the soil is more alkaline, the flowers of your hydrangea will lean towards a pink or red hue.
Keep in mind that not all hydrangeas change colors. White flowers will always remain white. Furthermore, bigleaf hydrangeas are more likely to change color than other species. Additionally, while the acidity of the soil has an impact on the hue, the intensity of the color largely depends on the variety.
How to Keep Hydrangeas Red
If your red hydrangeas start turning pale or getting a bluish or purple hue, this means the soil is probably too acidic.
In order for the flowers to remain red, the plants shouldn’t be getting aluminum from the soil. A higher pH level in the soil will generally result in less aluminum being taken in by the plant. If you want to be sure, you can purchase a soil testing kit from your local garden equipment store in order to determine the exact pH value of the soil.
According to Plant Addicts, your goal is to get the pH from the soil somewhere between 6.0 and 6.2. It is also possible to check the acidity of the soil without any special equipment. To learn how to do this, check out this guide on Garden Therapy. To make the soil more acidic, you can try adding dolomitic lime from time to time.
Plant Addicts also recommends using a fertilizer that contains high levels phosphorus as an alternative strategy. This helps to reduce the levels of aluminum that get to the plant and thus keep the flowers red. If none of this works, the soil in your garden might just be very rich in aluminum. If this is a case, you might want to consider growing your red hydrangeas in large pots, since it’s much easier to control all the conditions this way.
Red Hydrangea Care
All hydrangeas require at least a couple of hours of sun exposure during the day. However, it’s also possible to grow some varieties in partial shade.
They don’t like dry soil, so the area around this plants should always be somewhat moist. They also thrive in rich soils, so you should definitely consider adding compost to the soil if necessary.