Which hydrangea is cold hardy?
Hydrangea paniculata is one of the hardiest species; it thrives in Zones 4-8.
Effectively, a hydrangea should be able to sustain a temperature of minus-10 degrees. But in the real world, temperatures as low as 12 degrees — and late fall or early spring freezes — may reduce the flowering capability of this hydrangea.
Hydrangea paniculata 'Tardiva' has a more open panicle with more tiny fertile florets and a few large sterile ones. The flower heads are carried on upright stems and remain beautiful through winter whatever the weather.
Hardy hydrangea - Hydrangea paniculata may just be the plant everyone's been looking for. It's a very hardy plant (USDA zone 4) and forms its buds in early summer just before it blooms in mid-summer. The flowers which appear in July or August make great cut flowers or can be easily dried to create lovely arrangements.
Temperature and Humidity
Hydrangea can be grown in a variety of hardiness zones and can even be overwintered in some areas. Mature hydrangea can handle temperatures as low as 32 degrees Fahrenheit, but younger plants should be kept at temperatures no lower than 35 to 40 degrees Fahrenheit.
Oakleaf varieties are the easiest type of hydrangeas for beginners to grow. Why are oakleaf hydrangeas so easy? They aren't picky! Oakleaf hydrangeas can tolerate colder weather, handle more sun, withstand drought, are more disease/pest resistant and grow in sandy soil better than other hydrangeas.
Some varieties, like smooth hydrangea (“Annabelle”) and panicle, or PG hydrangea, are very cold-hardy and bloom on new wood. If these are the species in your garden, you don't have to worry about winter kill on hydrangea. They don't need protection unless the temperature dips below negative 30 degrees F. (-34 C.).
Whether or not hydrangeas need protection depends on how cold the winter temperatures drop. If the air temperature doesn't go below 0 degrees (zone 7) there is no need for winter protection. In colder climates, wrap or completely cover marginally hardy hydrangeas.
Potted hydrangeas overwinter best in a garage or basem*nt where the temperature stays cool but doesn't freeze. The plants will go dormant, but you'll still need to water the pots occasionally, about once a month, to keep the roots moist, until spring.
What do oakleaf hydrangeas look like in winter?
Oakleaf hydrangea is the only member of the genus that provides any significant fall foliage coloration. In November and December, when most other deciduous plants have shed their leaves, the oakleaf hydrangea remains fully clothed in stunning deep red to purple leaves that linger well into winter.
You don't have to clip off the old flowers unless you don't like how they look. If you object to their appearance as they turn brown, by all means clip them off. Some people cut them while they're still colorful and use them for bouquets indoors.
Panicle hydrangeas are a fantastic choice for adding late-season interest to your garden. As other plants start to fade, panicle hydrangeas burst into bloom, stealing the spotlight with their showy panicles of flowers. Their long-lasting flowers persist well into the fall, extending the beauty of your garden.
Some gardeners report success in turning their hydrangeas blue by applying coffee grounds to the soil. The coffee grounds make the soil more acidic, allowing the hydrangea to more easily absorb aluminum. In addition, fruit peels, lawn clippings, peat moss and pine needles, are thought to have a similar effect.
Paniculata and smoothleaf hydrangeas are generally very cold hardy, as are oakleaf hydrangeas and climbing hydrangeas, so these varieties don't usually need additional winter protection. Macrophylla hydrangeas, however, are a different story.
You should deadhead throughout the blooming season to keep your hydrangeas looking their beast and encourage new flower growth. However, stop deadheading hydrangea shrubs in mid to late fall, leaving any spent blooms in place.
The “beginner” hydrangea, or one that requires the lowest maintenance, are the oakleaf varieties. Not only do they tolerate colder weather and can withstand drought, but they are also more resistant to diseases and pests. These hydrangeas can even grow in sandy soil, and they love the sun!
Most hydrangeas prefer only morning sun. Yet one type of hydrangea can soak up the sun all day: the panicle hydrangea. While they can stand the sun, these do just fine in partial shade, too. Plus, panicle hydrangeas are the hardiest hydrangeas.
You'll find potted hydrangeas for sale at nurseries during the growing season. If possible, buy your plant when it's blooming, so you're sure you're getting the flower type—and color—you want. You should be able to lift or slide (lay the plant on its side) the hydrangea from its pot to get a look at its roots.
Hydrangeas grow best in full sun (more than 6 hours sun) to part sun (4-6 hours sun). With that being said, all hydrangeas can handle some shade, but the timing and type of shade are important to consider. They can be in full shade during the hottest part of the day, as long as they are getting some morning sun.
Will hydrangeas come back after a freeze?
Even though it can be a big setback, your Hydrangea can almost always recover from damage caused by cold and frost. To treat damaged Hydrangeas, wait until the temperature has warmed up and prune back the affected growth. Your Hydrangea may still bloom this year and should be back to usual growing habits next spring.
Unlike other hydrangea varieties, Endless Summer hydrangeas have excellent winter hardiness and can withstand winter temperatures as low as -30 degrees Fahrenheit (or -34.4 degrees Celsius) at the coldest. This means that flowering is quite reliable regardless of winter temperatures.
- Prune away the dead branches. ...
- Build a frame around your hydrangea plant with stakes of wood. ...
- Wrap chicken wire around the frame that you built. ...
- Fill the cage with mulch, pine needles or leaves.
Hydrangeas are hardy shrubs that can survive a winter freeze. As long as the shrub isn't subjected to repeated below zero temperatures, most species of hydrangea will be just fine through colder weather.
*We don't recommend oakleaf hydrangeas because they don't often look their best when grown in a container. They flourish when planted in the ground. But if you enjoy the look, go for it!
Unless the shrubs are planted in a raised bed that sits above the root system of trees, avoid planting hydrangeas directly beneath trees where they must compete for water and nutrition. The shrubs grow best in soil that contains plenty of organic material and good drainage.
This timing will vary by region. For instance, in areas with winter freezing and snow, hydrangeas should be planted in early spring or early fall (as soon as summer heat breaks). In warmer regions with mild winters, the window for planting hydrangeas is longer, from fall all the way through to early spring.
What happens if you don't prune hydrangeas? If you don't prune hydrangeas then they can eventually resemble a tangled mass of woody stems, and the flowers will become smaller and less showy. If your hydrangeas are not blooming, lack of pruning is often a reason.
Temperature requirements
When actively blooming, they will remain in the best condition if kept cool, around 50-60 degrees. During the rest period in fall and early winter, they should be kept around 45 degrees.
But when to prune them? Prune fall blooming hydrangeas, or old wood bloomers, after they bloom in the summer. If you prune old wooded hydrangeas in fall, you are cutting off next seasons blooms. Summer blooming hydrangeas, or those that bloom on new wood, are pruned in the fall, after they stop blooming.
What is the difference between Snowflake and snow Queen hydrangeas?
Snowflake – This midsize oakleaf grows 4 to 6 feet tall and wide, with oversize summer clusters of double flowers. Fall foliage is purple and crimson. Snow Queen – This mid-size shrub grows 4 to 5 feet tall, but spreads up to 6 feet wide. Midsummer blooms shift from white to rosy pink.
Sturdier than its cousins, the oakleaf hydrangea can withstand a wider range of climate conditions than most bigleaf hydrangeas. Oakleaf hydrangeas can survive drier conditions, and are more winter hardy.
This hydrangea grows easily in part shade locations. If the overall size is an issue, a good substitute is 'Snow Queen' – still large at 6-8' tall, but smaller than 'Alice' at 10-15'. If you have enough space, 'Alice' is a fabulous choice to help create a wonderland in your garden.
They're supposed to lose their leaves this time of year. Make sure it stays hydrated throughout the winter if you don't have snow cover. Even though the plants are dormant, they still need some hydration at their roots. Snow cover not only provides insulation, but also a water source.
In late winter or early spring, these shrubs can be cut all the way back to the ground. Smooth hydrangeas will produce much larger blooms if pruned hard like this each year, but many gardeners opt for smaller blooms on sturdier stems.
Frigid winter temperatures, as well as winter winds, can cause winter kill on hydrangeas. The low winter temperatures can kill the plant, or they might die because of drying out caused by winds.
Important: Since hydrangeas tend to set their blooms on the ends of the branches, it is important to keep these covered all winter. Most insulating materials will pack down somewhat during the winter and expose the branch tips, so the material must either be replaced or secured in place.
The best place to plant hydrangeas is in a sheltered location with sunny mornings and shady afternoons. You often find this on the north or south side of your home. Avoid planting directly underneath trees, which can lead to competition for water and nutrients.
Best Types of Hydrangeas for Full Sun
In many areas, the blooms dry on the plant in the fall and continue looking good through most of the winter. Hydrangea paniculata is one of the hardiest species; it thrives in Zones 4-8.
Incrediball hydrangea will make you say WOW - it's an improved version of the garden classic 'Annabelle' hydrangea, but with strong, sturdy stems that don't flop over and extra-large blooms to boot. White flowers begin to appear in mid-summer and open to enormous snowballs, nearly the size of basketballs!
What is the most popular hydrangea?
Bigleaf Hydrangeas
These are one of the most well-known varieties of hydrangeas. Their large, rounded flower heads are most often pink or blue—and are stand-outs in any garden. As with other hydrangea types, gardeners can achieve a multi-colored or color change effect by adjusting the soil's pH.
Some of the most popular reblooming hydrangea cultivars include 'Endless Summer', 'Summer Crush', 'Bloomstruck', 'Blushing Bride', 'Tuff Stuff', and 'Penny Mac'. Most are cultivars of bigleaf hydrangea, with the odd reblooming mountain hydrangea also available.
'All Summer Beauty' macrophylla blooms on both old and new wood, stunning blue mophead hydrangea that blooms all summer long. Hydrangeas traditionally bloom on “old wood”, meaning last year's growth but 'All Summer Beauty' is one of a new breed that reblooms on the current year's growth as well!
Oakleaf Hydrangea – If you live in an arid part of zone 9, such as California, the oakleaf hydrangea is a good choice. It has thick leaves that retain water well and help it get through periods of drought without having to be watered all the time.
Shade-Loving Hydrangeas
Annabelle, Invincibelle, and Incrediball are three hydrangeas that perform well in mostly shaded sites. All three of these like plenty of moisture and protection from the afternoon sun for best blooming.
Heat tolerant to USDA zone 9, 'Limelight' hydrangea is a stand out among panicle hydrangeas in its ability to thrive in warm climates.
Bigleaf hydrangeas (Hydrangea macrophylla) have smaller, ball-shaped blooms that are usually blue or pink but can be white, red, purple, or a mix of colors. Another way to differentiate them is by their woody stem. Endless Summer® Hydrangeas are all bigleaf hydrangeas. Prefer morning sun and afternoon shade.
Endless Summer Hydrangeas are unique, taking the traditional hydrangea to the next level. They can grow their enormous, bold flowers on both old and new wood—making for an exceedingly long blooming season and the potential for reblooms.
Hydrangeas are long-lived shrubs, sometimes living for up to 50 years if properly cared for. They enjoy morning sun but afternoon shade, and they need frequent watering during the growing season. Prune them in the fall after the blooms fade so they can grow on strong stems the following summer.
If watered properly, Endless Summer® Hydrangeas (Hydrangea macrophylla) will bloom on both old and new wood throughout the summer. Another advantage to planting these repeat blooming hydrangeas is that if there is a cold winter, it will only kill back the early flower buds.
What are the hydrangeas that don't fall over?
Best Panicle Hydrangea: Fire Light
This plant grows about 8 feet tall in sun to part shade and has strong stems that won't flop over despite the weight of its football-size flower heads. It is also very hardy, overwintering in Zones 3-8.
Most hydrangeas prefer only morning sun. Yet one type of hydrangea can soak up the sun all day: the panicle hydrangea. While they can stand the sun, these do just fine in partial shade, too.
Many hydrangea bushes prefer some shade, especially in warmer climates, however, there are cultivars that can not only tolerate sun but also thrive in it. We have versatile hydrangeas that can grow in full shade or full sun.
