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Hydrangea Seemannii To Grow & Care Via Best Guide

Be careful about growing Hydrangea Seemannii indoors because this climber can spread well over 30 feet.

Generally, Hydrangea Seemannii is a slow-growing climber that grows best in dappled sunlight with well-draining moist soil, warm temperature (60–70°F), and moderate humidity, with occasional pruning after flowering.

In fact, it makes reliable, low-maintenance houseplants and even flowers indoors.

Continue reading to know more about growing for these climbers.

Overview of Hydrangea Seemannii

Hydrangea Seemanii is an evergreen climber commonly known as Seemann’s Hydrangea, Mexican Climbing Hydrangea, or Climbing Hydrangea.

Originally from the cloud forests of Costa Rica, Honduras, and Nicaragua, it was introduced to Europe and North America by Berthold Seemann, a 19th-century German botanist.

Hydrangea Seemannii flowers
Hydrangea Seemannii’s ability to adapt, climb, and grow flowers in any environment makes it interesting.

Here is a list of basics that you should know about Hydrangea Seemanii.

Botanical NameHydrangea seemannii
Common NameSeemann's Hydrangea, Climbing Hydrangea
OriginCloud forests of Central America
USDA zone8 to 10
Plant typeClimbing Vine
Grown forOrnamental purposes, covering walls, fences, trellises
Leaf sizeMedium to Large (Up to 15 cm)
FoliageGlossy, Dark Green, and Evergreen
Height/SpreadUp to 50 feet (15 meters) and spreads 16 feet (5m)
Age10-20 years
Blooming PeriodSummer
FlowerLacecap-like clusters with creamy white to pale green/yellow showy flowers
ToxicityLow levels of toxic compounds like cyanogenic glycosides, potentially causing gastrointestinal upset if ingested

Many gardeners prefer growing them near windows, where they can enjoy the sunlight.

However, it is a very slow grower, taking years to flower and over ten years to reach its full height.

When cared for, it will thrive and enhance your home decor, like Golden Pothos and climbing Philodendrons.

Hydrangea Seemannii –Grow & Care Guide

Hydrangea Seemannii is a very low-maintenance plant that does well in varied conditions.

In fact, they are not very particular about growing conditions unless they are kept in extreme conditions.

Here is the primary care guide.

RequirementsOptimum Condition
LightPartial to dappled Sunlight for 4-6 hours
WateringKeep soil consistently moist
Water every5-10 days
Temperature60°F to 70°F (15°C to 21°C)
HumidityOver 60%
Ideal Soil MixWell-draining doil, organic-rich mix with peat moss
FertilizationThrice in a year (Early Spring, Early May, and late July)
RepottingRepot When Necessary or Plant Outgrows Container
PruningMinimal pruning, remove damaged growth, and flowers
PropagationPlant semi-ripe stem cuttings
or root cuttings in summer or autumn
PestsAphids, spider mites, and mealybugs
DiseaseBotrytis blight, leaf spots, and Powdery mildew

1. Sunlight & Temperature

Hydrangeas are tropical plants that do well in dappled or partial sunlight that copy their clouded forest environment.

However, beware of growing them in full shade, which may prevent vertical growth and flowering altogether.

Keep Hydrangea Seemannii in bright areas around the house that receive at least 4-6 hours of sunlight but avoid direct sunlight.

Sunburn or leaf scorch due to excessive sunlight will turn brown and crispy. Trim off damaged leaves to encourage new growth.

Similarly, an ideal temperature range between 60 to 70°F (15-21°C) is essential to maintain perfect transpiration.

Freezing temperatures can lead to wilting, browning, and stem diebacks.

Hence, move them away from open spaces in autumn and winter when the temperature fluctuates. Additionally, mulch the soil or use protection.

Quick Tip: LED grow light is optional as Hydrangea Seemannii does well in low lights. Instead, use them to compensate for less sunlight in spring and summer.

2. Watering & Humidity

Hydrangea Seemannii prefers consistently moist soil but hates soggy soil.

Water your Hydrangea once every 7-10 days, about an inch in spring and summer, to ensure the soil remains moist. Reduce it to once in two weeks in fall and winter.

If you witness drooping leaves, yellowing foliage, or the presence of mold on the soil, rest assured you have overwatered the plant.

Allow the potting mix or Hydrangea soil to dry out before watering again, or better, check whether the top 1-inch of the soil feels dry.

On the other hand, dried or lack of humidity in Hydrangeas will show wilted leaves and crispy or browned edges due to excess transpiration.

Hydrangea Seemannii cloud forest environment
To mimic the cloud forest environment, you should boost the humidity level by misting the plant regularly or using a humidity tray.

Alternatively, you can group the plants together or install a room humidifier to keep the relative humidity above 60%.

Note: Humidity stressed (excess humidity) Hydrangea will show similar signs of an overwatered plant, which may invite fungal growth and root rot.

3. Soil Type & Fertilizer

When it comes to Hydrangea Seemannii, you should strictly use a well-draining soil mix to prevent waterlogging.

Prepare a DIY potting mix of organic-rich soil using peat moss, compost, aged bark, and lime. It ensures optimal soil acidity (5.5-7.0 pH), which Hydrangeas highly desire.

Moreover, it reduces the use of fertilizer for the first few months.

However, if you feel your Hydrangeas are growing slowly with small leaves and no flowers, consider fertilizing them.

Feed the Hydrangea plant with a balanced liquid fertilizer such as Jack’s Classic 20-20-20 or Jobe’s Organics 4-4-4 every month in spring and summer.

Otherwise, follow a standard process of fertilizing thrice a year.

Early SpringWhen plants are just leafing out
Early MayBoost the flower production
Late June/Early JulyHelp plants finish the summer strong

Be careful of yellowed leaves and stunted growth, the common signs of overfeeding, which requires leeching the salt by running the water through the soil.

4. Potting & Repotting

The choice of pot material is many; you can use plastic, clay, terracotta, wood, or even ceramic.

Use a pot at least an inch bigger than the plant root ball with multiple drainage holes at the bottom to drip the excess water seep out.

On the other hand, it does not require frequent repotting because the plant root is slow to grow.

Consider repotting them every 3-5 years or when the roots visibly come out of the drainage holes with stalled growth.

Steps to Repot Hydrangea Seemannii

  • Choose a slightly larger pot, at least 2-3 inches bigger than before.
  • Water the plant a day or two before repotting. Carefully slide out the plant and inspect the roots for damage.
  • Place a layer of fresh potting mix at the bottom of the new Hydrangea pot and position the Hydrangea plant in the center of the unique pot.
  • Ensure ‘roots first’ and add more soil around the sides until it is just an inch short from the top rim.
  • Water the Hydrangea plant thoroughly to settle the soil and eliminate air pockets.
  • Place the potted plant in a location with appropriate light.

5. Occasional Grooming

Hydrangea Seemannii is not very particular about grooming unless the plant gets bushy and uncontrollable.

Pruning is generally done after flowering, typically in late spring or early summer. Removing dead/damaged leaves, wilted flowers, and leggy stems with no leaves.

Similarly, occasional grooming will help detect and remove pests and diseases on time.

Pests like spider mites, mealybugs, and aphids leave visible signs on the leaves, such as pest eggs, spider webs, and leaf holes.

Better get rid of infected leaves to prevent further spread and spray neem oil or insecticidal soap to kill the remaining pests and eggs.

The plant suffering from Botrytis blight, leaf spot, or powdery mildew will show visibly damaged leaves: mottled leaves, yellow spots, dead flecks, ring spots, white substance on the leaves, etc.

Start with removing damaged leaves. Afterward, apply fungicides appropriate for houseplants to treat diseases.

Hydrangea Seemannii: All About Growth Rate 

Hydrangea Seemannii is grown for its vining stems with leathery-like leaves and flowers that bloom every summer.

It is an evergreen climbing plant that attaches itself to surfaces using aerial roots, reaching up to 50 feet in height and 15 feet wide.

Those grown without natural support (trees or walls) would require some support, such as trellis, to continue growing.

Similarly, the glossy green, ovate-shaped leaves will quickly reach 15 cm long, contributing to the plant’s overall appearance.

However, only matured Hydrangeas will flower, which may take a while as these woody vines take time to establish.

Expect to wait a few years before you see flowers forming in clusters in a creamy white to a pale green or yellow shade.

Remember, it is a slow-growing plant and may take 10-20 years to reach its full potential.

Hydrangea Seemannii Propagation Methods

Hydrangea Seemannii is easy to propagate and reproduce if you use healthy cuttings.

In fact, propagating Hydrangea Seemannii follows the same process as propagating Hoya Australis Lisa, Monstera Peru, or Pink Princess Philodendron.

There are two ways you can do it effectively.

1. Propagation via Stem Cuttings

  • Choose a healthy plant as your source for cuttings, and pick a non-flowering stem.
  • Using sharp, clean pruning shears, take 4-6 inches (10-15 cm) cuttings from the tips of healthy stems with at least two pairs of leaves.
  • Optionally, dip the cut end of the stem in the rooting hormone.
  • Fill small pots or containers with a well-draining potting mix and moisten it thoroughly.
  • Insert each cutting into the potting mix, ensuring at least one nodule (node) is buried in the soil.
  • Cover the Hydrangea pot with a transparant plastic bag or dome to create a mini greenhouse effect for humidity.
  • Please place it in a bright but indirect light location
  • After a few weeks, you should notice new growth in aerial roots.
  • Continue with regular care afterward to witness a new set of leaves.

Alternatively, you can root the Hydrangea stem cuttings in water by inserting the cuttings into a glass of clear water.

Check for signs of new growth in aerial roots. Allow them to grow an inch or more before moving into a soil mix.

2. Propagation via Root Cuttings

Dig up a well-established plant for root cutting during dormancy, fall or winter, or repotting.

  • Cut the root into 2-4 inches (5-10 cm) long sections. Each section should have at least one healthy root.
  • Optionally, dip the cut ends of the root sections in the rooting hormone.
  • Fill small pots with the same well-draining potting mix and moisten them well.
  • Insert the root sections into the potting mix, ensuring the cut end faces down and the root points upwards.
  • Place a clear plastic bag over it to create a humid environment.
  • Place it in a bright section of your home away from direct sunlight.

Root cuttings may take a while to produce new stems and leaves.

After a month or two, you should notice new growth from within the soil.

Continue providing regular care to encourage healthy growth and repot once they get too big for the current pot.

Toxicity of Hydrangea Seemannii

All parts of the Hydrangea plant are toxic as they contain cyanogenic glycoside or cyanide.

Consuming even a small amount of the leaves, buds, flowers, and bark will release the poison, leading to immediate signs.

Therefore, you should keep them away from children and pets’ reach, as suggested by ASPCA.

Check for signs like shortness of breath, dizziness, vomiting, diarrhea, fainting, and a rapid pulse in pets. In some cases, overeating plants can even lead to death.

Hydrangea Seemannii for Sale

If propagating Hydrangea Seemannii is out of option, here is your chance to obtain young or well-established plants.

Check out the list of some online sellers specializing in Hydrangea Seemannii.

Stores to buyShipping Time
Diggging Dog3 days
Mr. Maple-
Keeping It Green Nursery3-10 days

FAQs About Hydrangea Seemannii

How to Grow Hydrangea Seemannii Outdoors?

Select a place with partial to full shade and protect the plant from the harsh midday sun. Outdoor-grown Seemannii may require frequent watering and protection from cold stress.

Does Seemannii bloom around the year?

Nope, Hydrangea Seemanni will only flower in summer when the plant has reached maturity, which may take a few years.

Hydrangea Seemannii flowering chart
Hydrangea Seemannii flowering chart

Does Seemannii flower require deadheading?

Removing spent flowers after they have faded is best to encourage continuous flowering. Otherwise, remove flower buds to redirect energy toward foliage growth.

From Editorial Team


Do not worry about not finding Hydrangea Seemannii in the market, as they are not classified as rare.

Moreover, you can quickly grow them along with other climbing viners such as Pothos or Philodendrons.

They share similar care requirements and may benefit from each other’s presence, especially humidity.

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