Hydrangeas are one of the most recognizable and popular shrubbing plants for its gorgeous blooms. There are many varieties in this large plant family, but few are commonly grown in gardens. Among the best flowering shrubs are the Smooth Hydrangea (Hydrangea arborescens) also referred to as Wild Hydrangea.
These rapidly expanding, bushy shrubs thrive when buried in the fall and rarely grow more than five feet tall. They flourish in partial sunlight areas and require well-drained soil. Leaning on the toxic side, it’s worth mentioning that all parts of the hydrangea plant can be toxic to both humans and animals. Read on for care and cultivation tips for the new palm.
Names: Smooth Hydrangea, Wild Hydrangea
Common Name: Smooth Hydrangea Botanical Name: Hydrangea arborescens
Family: Hydrangeaceae
Plant Type: Deciduous shrub
Mature Size: 3 to 10 feet tall
Sun Exposure: Prefers partial shadeSun Exposure: Prefers partial shade
Soil: Well-drained soil is ideal
Soil pH: Tolerates acid, neutral and alkaline soils
Bloom Time Flowers summer
Flower Color: Typically white
Hardiness Zones: 3-9 in the USA
Native Range: Eastern United States
Toxicity: The plant’s parts are toxic to humans and pets
Smooth Hydrangea Care
For proper development, Smooth Hydrangea needs special caring prerequisites:
Spacing: If planting shrubs, they should be at least five feet apart so they have plenty of space to grow.
Light: These plants prefer partial shade, like bright sun will but are protected from the harsh midday sunshine.
Soil: They should have well-draining soil, as they could get waterlogged, which could damage their roots.
Light
Hydrangea arborescens (Smooth Hydrangea):Likes partial shade (least light) and prefers dappled sunlight. Although it will also stand full sun, protection from hot afternoon sun is indispensable in intense southern areas.
Soil
Smooth Hydrangeas are fairly adaptable when it comes to soil, though they prefer it moist and well-drained, they will tolerate less than perfect conditions. They prefer loamy, nutrient-rich acidic pH soils for best growth.
Water
Smooth Hydrangea demands more water during the hot, dry summers or when the shrub is in full sun in the north; the soil should be kept moist during the growing season. Adding a layer of mulch at its base can also help retain moisture and keep the plant hydrated.
Temperature and Humidity
Smooth Hydrangeas are also one of the most cold-hardy varieties of hydrangea, as they are notably cold hardy and do not usually require additional protection in the winter. However, in particularly cold winters, they can suffer dieback. These hydrangeas do best in daytime temperatures in the 70s Fahrenheit during their growing season. They prefer atmosphere that’s humid and protected from strong winds for best health and growth.
Fertilizer
Smooth Hydrangeas (Hydrangea arborescens) prefer a balanced, all-purpose fertilizer to promote their vigor and growth. Gardeners wanting to increase the number and size of their blooms are recommended fertilizer high in phosphorus, sometimes referred to as “bloom boost” or with a nutrient ratio of 10-20-20. And in spring, fertilizer application can be imperative for preparing for the growing season. However, do not over-fertilize as too many nutrients can damage the plant by burning the leaves or encouraging leaf production at the expense of flowers. Smooth Hydrangeas’ flower color is not affected by soil pH changes, like Big Leaf Hydrangeas.
Types of Smooth Hydrangea
At a more advanced level, Hydrangea arborescens has a number of intriguing cultivars, and they have differences in both characteristics and appearance. Some of the best varieties are:
Incrediball Hydrangea (‘Hydrangea arborescens ‘Abetwo’ Incrediball’): A star of the show for its enormous, globe-shaped flowers and strong, erect supports.
Invincibelle Spirit Hydrangea (Hydrangea arborescens ‘NCHA1’ Invincibelle Spirit): A pink variety, it’s a bit showier than the common white one.
Hayes Starburst Hydrangea (‘Hydrangea arborescens ‘Hayes Starburst’): This variety is known for its unique double blooms that offer stunning contrast from the traditional white flowers featured in Smooth Hydrangeas.
Pruning
Smooths are much easier to prune because they bloom on new growth. These plants can be cut back to the ground each winter, or early spring, in order to promote vigorous stem growth and flowering that is steady. Another method is to remove any weak, damaged, or diseased stems selectively for health and aesthetic purposes.
Both root and stem cuttings can be used successfully to grow this fast-spreading plant. Here’s how to propagate softwood cuttings, provided the plant is not under patent protection:
Cutting Prep: Clip 5 inches from a healthy stem, discarding leaves close to the cut end to avoid rot.
Rooting Hormone: To promote root growth and protect against fungi, lightly coat the cut end in rooting hormone.
Potting Mix: Use a sterile, well-draining medium, such as slightly moist sand or vermiculite, when planting. Keep the medium moist but not saturated.
Cover: Put a plastic cover on the cutting itself to hold in humidity. Avoid touching leaves with plastic to prevent mold or rot.
Location: Place the cutting in an area with bright, indirect sunlight. The space should be warm but not in the direct sun, to avoid overheating.
Watering: When the medium starts to dry, water the medium to keep it moist-flowing until roots develop.
Starting to Grow: When viable cutting form roots they will usually do so in the first couple weeks and can then be transplanted to a more permanent location.
These steps help you propagate new Smooth Hydrangea plants and even get some help in expanding your garden with them or possibly sharing them with fellow gardening enthusiasts.
Overwintering
As winter arrives, the Smooth Hydrangea will enter dormancy. Overwintering — guidelines for the most part required to make sure their survival and health in the cold months, especially for those developed outside:
Outdoor Plants: It is important to wrap and cover outdoor Smooth Hydrangeas to protect the plant and its root system from freezing temperatures. Wrap the plant in burlap or a frost cloth, and consider mulch heavily around the base to insulate the roots.
Hydrangeas: Potted Hydrangeas: If your hydrangeas is growing potted, moving them inside or in a greenhouse will help protect them from the cold. This step is crucial for regions prone to freezing temperatures as well.
Water: In winter, when the plant enters a period of dormancy, reduce watering to once a month. This is just enough to keep the roots damp without shing to the soil, which might result in root rot in the cold.
Spring Revival: When spring arrives, and the temperatures rise, begin acclimating your outdoor plants to more regular watering and remove the coverings. Container plants can also go back outside once frost no longer threatens, transitioning them gradually back into the growing season.
By following these simple steps for overwintering, you can keep your Smooth Hydrangeas alive and well until spring, when they can return to vigorous growth and large flowers.
Common Pests & Plant Diseases
Smooth Hydrangeas are generally hardy and not troubled by many serious pests or diseases. But it requires vigilance to keep them healthy. Key pests and diseases to look out for include:
Aphids: These tiny, sap-drinking pests can congregate on the undersides of leaves and stems, weakening the plant by siphoning off its juices.
Japanese Beetles: Known for their ravenous appetite, these beetles will eat hydrangea leaves, leaving skeletonized foliage behind.
Spider mites: Being small can be an advantage, but spider mites can create problems by piercing the cells in the plants to devour. They typically leave wispy webs on the plant.
Powdery Mildew: This fungal disease prefers humid conditions, causing a white, powdery film on leaves. It can block photosynthesis and stunt the plant.
To help control these pests and diseases, here are some tips:
Regular inspection: Inspect your plants regularly for any signs of pests or disease, so you can address the issue as soon as possible.
Keep it Dry: Water the plants at soil level so you don’t wet the foliage, which can help prevent powdery mildew.
Adequate Plant Spacing: Give plants adequate space between them, as it will enhance air circulation during the hot summer months and discourage powdery mildew, as well as make it more challenging for pests to spread.
Natural Defenders: For insects that prey on aphids and mites, like ladybugs and lacewings, plant a variety of plants that attract these and other beneficial insects.
Fungicides: If the problem is severe, you may need a fungicide. Select a product designed for this use with hydrangeas and follow its application instructions closely.
These practices will enable you to keep your Smooth Hydrangeas healthy and thriving, making them less susceptible to the effects of common pests and illnesses.
How to Make Smooth Hydrangea Bloom
Known for their long flowering period, often from early summer right through to late autumn, Smooth Hydrangeas deliver beautiful blooms.
What Makes Smooth Hydrangea Blooms Different
Flowers: They have small, white flowers, which are collected in clusters that have in aggregate heads of up to 12 inches wide, providing an attractive display.
Fragrance: The flowers are sweet-smelling, which is nice for garden visitors seeing them, and draws a diverse range of pollinators.
THE BASICS Thank You Moonflowers for Your Blooms
Pruning: Regularly prune each year during late winter or early spring. Smooth Hydrangeas bloom on new wood so by making a hard cutback, this encourages new growth of stems which will produce new flowers.
Sunlight: The amount of light should be appropriate Although they do well in partial shade, excessive shade limits flowering. Give them filtered sunlight or morning sun with afternoon shade — most especially in hotter climates.
Fertilization: Stay away from high-nitrogen fertilizers, which will make them leafy with little blooms. Take a break from the tomato fertilizer and use a balanced fertilizer, or one that is a little higher in phosphorus to encourage even more flowers.
Here, you may maximize the blossoming possibilities of your Smooth Hydrangea, for a magnificent decoration of bloom in the summer months!
Common Growing Problems
Smooth Hydrangea has a few typical growing challenges. Identifying and correcting such problems early will help you keep your plant healthy and attractive.
Yellowing Leaves
Cause: If leaves paler than usual arrive, they likely said a lack of one or more nutrients is underfoot, most frequently, chlorophyll production — often due to inconsistent iron content.
Solution: Use iron-rich fertilizer and keep the soil acidic, as this helps the plant access iron more easily.
Drooping Leaves
Cause: Leaves droop due to either overwatering, or too much sun, both of which stress the plant.
Solution: Water plants according to their needs; in the right amount (moistened soil, not waterlogged); provide partial shade when the heat is too much (this is crucial in hot climates) — sun stress does the plant in.
Hydrangea Not Blooming
Reasons Your Smooth Hydrangea May Not Bloom:
047515739413 Which could lead to improper pruning: Pruning at the wrong time of year can take away flower buds.
Too Much Shade: Too little sun can prevent blooming.
Nutrient Imbalance: Too much nitrogen promotes foliage growth over flowers.
Winter Kill: If temperatures in winter are too cold, they can damage or kill flower buds.
Age of Plant: Very young plants may not flower profusely until they are more established.
Drought Stress: Lack of water during bud formation may hinder blooming.
Wrong Fertilization: Mistakenly delivering the fertilizer can easily prevent blooming.
Pest or Disease Pressure: Pests or diseases can put stress on the plant that affect its ability to bloom.
By addressing these particular things with appropriate cultural practices and care, you will combat common growing challenges and encourage your Smooth Hydrangea to thrive.
How Do I Grow Smooth Hydrangea?
A: Plant Smooth Hydrangea in fall or early spring. Opt for partial shade and well-drained soil. Make a hole as deep and twice as wide as the root ball, set the plant in the hole, backfill with soil and water well.
When should you prune Smooth Hydrangea?
Q: When is the best time to prune Smooth Hydrangea (Hydrangea macrophylla) plants? (Christine K.) A: The ideal time to prune is before the new growth starts late in winter or early spring, since Smooth Hydrangea flowers on new wood. Pruning stimulates new growth and higher volume blooms.
How often should Smooth Hydrangea be watered?
A: Water newly planted hydrangeas frequently to keep the soil moist, not soggy. When their roots are established, they need less frequent watering, but it’s essential to keep them moist during dry times.
When Should You Fertilize Smooth Hydrangea?
A: Fertilize in early spring with a balanced/all-purpose fertilizer. Choose a fertilizer higher in phosphorus to encourage more blooms. Stay away from high-nitrogen fertilizers, which can encourage foliage over flowers.
Is Smooth Hydrangea sun tolerant?
Q: Are they full sun plants, partial sun plants, or full shade plants?
My Smooth Hydrangea (Hydrangea arborescens) leaves are yellowing; what gives?
So if your plant is getting yellow leaves, it can be that it is just missing nutrients, typically iron. Apply an iron-fortified fertilizer and make sure the soil is acidic enough for better nutrient uptake.
Does Smooth Hydrangea grow in a pot?
A: Definitely, Smooth Hydrangea will thrive in large pots that have adequate drainage holes. Choose a potting mix that drains well, and a pot that allows for growth.
Written by: Sandy V.2010-10-2410:38:00How to Propagate Smooth Hydrangea
A: Propagate softwood cuttings in early summer. Snip a 5-inch stem, strip off lower leaves, dip in rooting hormone and stick in well-drained medium. Until roots form, keep moist and covered with plastic.
Is Smooth Hydrangea toxic?
A: Yes, the Smooth Hydrangea is toxic to people and pets if eaten, and all parts of the plant are toxic, so it’s best to plant them away from play areas and keep an eye on pets and children around the plants.
What would encourage my Smooth Hydrangea to bloom?
A: Make sure your plant is getting suitable light, don’t give high nitrogen fertilizers and prune properly in late winter or early spring to stimulate flowering on new growth
