How to Care for Hydrangeas Outdoors & Where to Plant Hydrangeas in the Ground

In this article, we’ll be going through how to care for hydrangeas outdoors from planting them in the ground to changing the colors of the flowers! They are lofty, large plants that don’t need full sunlight but do need a lot of space, depending on the variety.

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Hydrangeas make a great display shrub, whether you want one or two to grace a pathway or a long bush along a tree line! They’re common yet elegant flowering shrubs whose flowers are often found in bouquets and have cultural meanings.

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Table of Contents

What is a Hydrangea? What Does a Hydrangea Look Like?

A hydrangea is a large, leafy shrub that produces several beautiful flowers per plant in a range of different colors, including pink, white, and blue. They’re often grown in rows to create bushes covered in blooming flower heads.

The most common cultivated variety is the hydrangea macrophylla, also known as a hortensia.

The cultural meaning of the flowers is boastfulness and vanity, since the plants produce many showy flowers but don’t drop many seeds.

Important note: Hydrangea leaves contain cyanogenic compounds and are therefore toxic.

How big do hydrangeas get?

Dwarf hydrangeas grow 2 to 4 feet tall and wide, whereas larger bushes can grow up to 8 feet tall, and climbing vine varieties can grow up to 50 feet tall!

Hydrangeas require a certain amount of care throughout their life cycle, even after they’re fully grown. Stick around and we’ll show you the ropes when it comes to growing them!

How to Plant Hydrangeas in the Ground

Hydrangeas are grown from cuttings almost exclusively. They can be grown from seeds but it’s not easy or commonly done. If you are ready to plant your hydrangeas in the ground for a lovely garden, let’s follow this step-by-step guide!

Step 1: Choose a Proper Location

You should select your location based on how big a mature hydrangea of your chosen species gets, as well as the amount of sun it requires.

Most hydrangeas thrive when there is direct sunlight during the morning hours, and partial shade during the hot afternoons.

However, some hydrangea varieties like the panicles do well in direct sunlight.

If you’re not sure about your hydrangea varieties, take a look at the tag on your hydrangea to see what kind it is and how much sun it needs, or read our post on Different Types of Hydrangea Bushes.

Step 2: Dig a Hole That’s Wider and Slightly Deeper than the Pot

Dig a hole that’s two or three times wider than the pot, and make sure you don’t bury your hydrangea too deep! You want to plant it so that it’s either at the same level as the soil or slightly above.

This goes for most of your perennial plants too. The reason for this is to give those roots some space to spread out without struggling through tough, heavy soil. Let’s make it easier for them to do their thing!

Step 3: Loosen and Shake the Roots

When hydrangeas are kept in pots at the store, their roots can get all tangled up, which makes it tricky for them to spread out once you plant them.

To fix this, simply snip a few of the outer roots and give the rest a gentle shake to loosen them up. Easy peasy!

If your plants are looking a bit thirsty, make sure to give them a good watering before planting them in the ground. It’ll give them a nice boost before they go into the hole!

Step 4: Plant Hydrangeas into the Hole

Fill the soil into the hole while positioning the plant.
Press the soil gently. Just double-check that it’s not sitting too low, and if it is, we’ll just fill it up again. We’ll also give it a little pat to make sure there are no air pockets.

Step 5: Add 2″-3″ of Mulch

When you’re mulching your plants, it’s important to remember not to cover their base.

Hydrangeas and most plants actually need good airflow around their roots. So, avoid piling up the mulch too high. Instead, spread it out around the edges of the plant.

Step 6: Water your plant well

Make sure you give your hydrangeas a good soak at the roots.

You can grab a hose and really get in there to make sure they stay nice and hydrated. Keeping them moist is key, especially when they’re still working on growing their root systems.

Step 7: Care for your Hydrangeas Regularly

To keep your plants happy and hydrated, aim for about an inch of water per week.

Instead of giving them a quick sprinkle every day, it’s best to water deeply three times a week. This way, the water can reach all the way down to the lower roots and keep everything nice and nourished.

If your soil is already packed with nutrients, you might not even need any fertilizer.

However, if you want some fast-growing tips for hydrangeas, then our advice is to water the plants well to encourage root growth and fertilize regularly.

Make sure your fertilizer has phosphorous to encourage flower growth.

Fertilizer with high nitrogen levels will encourage the growth of foliage at the expense of the blooms. Hydrangeas are heavy feeders and they’ll grow faster with proper nutrition.

Growing hydrangeas in the ground means they are subject to the elements. In areas with high winds, it’s advisable to keep the stems short by pruning – this way they’ll be less likely to be broken off in a high wind.

Hydrangea plants like well-fertilized, well-draining soil with shade provided during the hottest parts of the day.
Add compost or fertilizer to the ground before planting if your soil is not rich in nutrient.
Your hydrangeas would ideally like to have full sun in the morning, with shade cover during the afternoon when the sun is hottest. Shade can be provided by nearby buildings or tall trees.
Be careful not to overshade your hydrangeas, since a total lack of direct sunlight will result in poor flowering.
Don’t plant your hydrangeas in soil that gets waterlogged due to poor draining.

When to Plant Hydrangeas

Fall is the best season to plant your hydrangeas, but you can plant in spring as well. These shoulder seasons do not have the extreme heat and cold of summer and winter, which is ideal for developing their root systems.
The best time of day to plant hydrangeas is early morning or late afternoon, times when the heat from the sun is not at maximum. You can also plant them on a cloudy day to reduce the chances of shock from the hot sun.

How to Care for Hydrangeas Outdoors

Hydrangeas grown outdoors in both pots and in the ground need certain care.

In windy regions, branches should be pruned shorter to prevent breaking during heavy winds. They also require watering, especially potted ones.
Hydrangeas are heavy-feeding plants and should be watered regularly to keep the soil consistently moist, especially in regions with sandy soils which drain the water more quickly.
Fertilizer should be added containing phosphorous which will encourage flower growth, especially if potted.

Do Hydrangeas Need Full Sunlight?

Hydrangeas like to have full, direct sunlight during the mornings, and shaded light in the afternoons during the heat of the day.
They need lots of light in order to flower properly, but scorching afternoon heat will damage the plants.
4 to 6 hours of direct sunlight per day is ideal, depending on the variety. The further north you live, the more hours of sunlight your bushes can take.
Varieties like Oakleafs and Mopheads can tolerate more shade than others, needing only 4 to 6 hours of direct sun per day.
Panicles can tolerate the most sun, needing 6 to 10 hours per day, depending on the hardiness zone you grow it in.

Caring for a Hydrangea – Soil

Soil for hydrangeas should be well-draining enough to prevent waterlogging, but not so well-draining that it dries out. Hydrangeas like consistent moisture levels.
Fertilizing is important for hydrangeas. They like to have plenty of nutrients and organic matter.
The soil pH can vary significantly with hydrangeas and the plant will be fine. In fact, the colors of the flowers will be different depending on how acidic or alkaline the soil is. The best pH range for the soil is between 5.5 and 7.
Sandy soils are problematic for hydrangeas since they are too well-draining and typically lack nutrients. Be sure to amend the ground by adding soil and compost if growing them in a sandy area.

Hydrangea Care: Watering

If your plants do not get enough water, you’ll notice that the leaves will begin to wilt and the flowering process will be stunted.
The best time of day for watering is the morning, since it prepares the plant for the heat of the day. This also gives the sun a chance to dry off the above-ground portion of the plant to prevent diseases.
1 inch of water per week is ideal. It’s better to give a deep watering 3 times per week rather than a light watering every day, since the water will reach the lower parts of the root system.

Hydrangea Hardiness Zone & Humidity

Different varieties of hydrangeas grow better in different regions. All 6 cultivated species grow well in USDA zones 6 and 7.

Hydrangea macrophylla (Bigleaf): USDA zones 5 to 9.
Hydrangea paniculata (Panicle): down to USDA zone 3, the hardiest of the hydrangeas for cold climates. Up to USDA zone 8.
Hydrangea quercifola (Oakleaf): USDA zones 5 to 9.
Hydrangea arborescens (Smooth): USDA zones 4 to 9.
Hydrangea serrata (Mountain): USDA zones 6 to 9. Vulnerable to cold but less so than the Bigleafs.
Hydrangea petiolaris (Climbing): USDA zones 4 to 7.

Hydrangea Care: Fertilizer

Hydrangeas require a lot of nutrients in order to be healthy.

Check the requirements of your individual variety. For instance, Bigleafs like to be fertilized multiple times throughout the growing season, whereas smooth hydrangeas only need to be fertilized once per year in late winter.
If your soil is already nutrient-rich, you may not require any fertilizer. If you’re not sure then you can have a soil test done. Too much nutrition causes the foliage to overdevelop and the flowers suffer as a result.

How to Prune Hydrangeas

Pruning is necessary to ensure that your plants are producing lots of flowers and keep the plant from growing too large. Always use pruning shears for cutting – don’t break stems by hand!

The best time of year to prune depends on your variety – some grow their flowers on old wood and some on new wood. Old wood is growth from the previous season and new wood is growth from the current season.

For old-wood varieties, you should prune immediately after the flowers have expired. This way, the bush can work on growth that will be old wood by the time the next season comes around.
For new-wood varieties, do your pruning in late winter or early spring. This way, the plant will be able to add lots of new growth.

How to Propagate Hydrangea Cuttings (Step by Step)

Cuttings should be taken during late spring to early fall while the foliage is still green. This will give it enough time to grow some roots before the winter cold takes over.

Choose a piece of new growth that hasn’t flowered yet, and cut a piece 5 inches long with at least 3 sets of leaf nodes.
Strip off all the leaves except the ones on the top node.
Choose a pot 6 inches in diameter and fill it with a sterile potting mix. Don’t use soil from outside.
Moisten the soil and make a hole in the middle of the dirt with a pencil. Place at least 2 leaf nodes under the surface.
Place a plastic bag over the plant to keep it humid. Use sticks to hold the bag up away from the leaves.
Place the plant in a warm location with indirect sunlight. Direct sunlight will damage the cutting!
After 4 to 8 weeks, your cutting should be well-rooted enough to plant outside or in a larger, permanent pot.

How to Change the Colors of Hydrangea Flowering Shrubs

You can change the colors of your hydrangea blooms by changing the pH of the soil. The best times of year for pH changes are spring and fall, so that the plant has a chance to absorb the product before blooming.

In more acidic soils with a pH of around 5.5, your flowers will have a deep blue.
For basic soils with a pH of 7 or higher, the flowers will be pink to red.
Products like sulfur or aluminum sulfate can be used to lower the pH of the soil.
Lime is typically used to raise the pH of soil.

How Long do Hydrangea Blooms Last?

The blooming times of hydrangeas depend on the species when planted outside. It may take 2 to 5 years after planting before your hydrangea starts budding.

Hydrangea macrophylla (French Bigleaf hydrangeas): late spring to midsummer
Panicles: late spring to early summer
Oakleaf hydrangeas: midsummer to early fall
Climbing hydrangeas: late spring until midsummer

There are many more types of hydrangeas than those listed here. You can learn more at the following link:

If you want to know more about helping your hydrangeas to bloom, follow this link:

How to Care for Hydrangeas Outdoors: Common Problems

Flowers not blooming: this may be the result of too much nitrogen-heavy fertilizer. Hydrangeas need phosphorous in order to bloom, whereas nitrogen is used by the plant for leaf development. You may have also pruned the flower buds off by accident – make sure you understand if your variety of hydrangea is a new wood or old wood variety.
Flowers turning brown: flowers will turn brown if underwatered, especially during the hot season.
Flowers are too small: this could be a case of too little sunlight or water, or too little phosphorous in the fertilizer.
Wilting flowers: flowers wilt when the plant is underwatered or receives too much sun.
Drooping leaves: this happens when the plant does not receive enough water.
Yellowing leaves: there are multiple reasons this may happen. Too much water will turn the leaves yellow. Your plant may also be lacking in nutrients like nitrogen or iron. It can also happen when the pH of the soil is too high (too alkaline).

Hydrangea Care in Spring

If your hydrangea variety is a new wood type, then you will want to do your pruning in early spring.
If you didn’t add a layer of mulch in the fall, it is still beneficial to add one in the spring. Mulch helps control weeds and keeps the moisture level consistent.
Depending on the variety of hydrangea, you may need to apply fertilizer.
If you are going to try to change the pH of the soil, spring is the best time to do so.

Hydrangea Care in Summer

You should increase your watering frequency during the heat of the summer, especially if you live in a hotter USDA zone. If you mulched before the summer then your hydrangeas will have an easier time staying moist.
If you added pH changers to the soil in spring to change the flower colors, check during the summer to see if they gradually change the way you expected.
Pruning for old wood varieties should take place in late summer after blooming has finished.

Caring for Hydrangeas in the Fall

Deadheading is a good idea regardless if your hydrangea variety is the old or new wood type. Dead flowers can catch ice and snow, which adds weight and stress on the stems. Deadheading also reduces the energy the plant has to expend during the cold season.
Adding mulch and compost to the soil is a great idea to protect the roots from sudden changes in temperature. Composting also ensures that there will be fresh nutrients for the plant come spring.

How to Care for Hydrangeas: Overwintering

In cold regions, build a protective shelter around your plants. Place stakes in the ground in a circle around the plant and wrap chicken wire around it. Then, fill this cylinder with leaves to create an insulated body around the plant. Oak leaves work best, since they don’t settle as much as most other leaves.
Hydrangeas in pots can be brought inside for winter, before the first frost. If you can’t bring them inside then you can cover them in a similar way as described above.

FAQs

Are Hydrangeas Perennials?

Yes, all hydrangeas come back every year – they are not annuals. They can live up to 50 years if properly cared for.

When do you Plant Hydrangeas?

The best times of year to plant hydrangeas are spring and fall, since they have the least extreme temperatures. As for the time of day, it’s best to plant them in the evening or morning so they don’t suffer shock from direct sunlight.

How Long do Hydrangeas Take to Grow?

Hydrangeas will begin producing flowers 2 to 5 years after planting – their growth rate depends on the variety. How fast and how tall they grow also depend on the species. They continue to grow throughout their lives and must be pruned to size.

Do Hydrangeas Spread?

Hydrangeas can spread by producing seeds, but they do not spread like weeds.

Do Hydrangeas Do Well in Shade?

Yes, hydrangeas prefer to be shaded during the hottest parts of the day.

How to Care for Hydrangeas Outdoors: Recap

Hydrangeas are wonderful flowering shrubs that can beautify an outdoor space. In this article you learned about how to care for hydrangeas outdoors, as well as where, when, and how to plant them in the ground. They don’t even require full sun, which makes these big bushes a great addition to a shelterbelt!

Hydrangeas are hardy plants, so if you run into trouble, information is widely available online or even at your local nursery. Don’t be afraid to reach out for help and don’t ever give up on your plants. You, too, can be a hydrangea master! Best of luck and happy growing!

Source: https://thelittle.garden
Category: Houseplants