Complete Guide to Hydrangeas: How to Grow & Care for Them

Read our guide to growing Hydrangeas in your garden or pots - All you need to know from planting to caring for your Hydrangeas

Welcome all to a wonderful and delighting article about how to grow one of the most beautiful and moment enhancing flowers on this magical living planet:  the hydrangea.

This flora is one of many people’s favorites.  And for good reason.  The hydrangea attracts one of our most valuable species, the bee.  It is good upon the eyes and soul; and apparently the root and rhizome can be used in treatment of urinary tract problems.  How useful, indeed.

Be careful, though, when it comes to eating/ingesting hydrangeas; as most parts are mildly toxic, containing a form of cyanide.

Types of Hydrangeas

There are about seventy-three different varieties of hydrangeas.  There are deciduous types and evergreen types; most are deciduous, though.

Some of the most popular types are:

  • Hydrangea macrophylla (big leaf)
  • Hydrangea arborescens (smooth)
  • Hydrangea anomala subsp petiolaris (climbing).

They are native to Asia and the Americas.  They have flower clusters (mop-head or lacecap style), are often lavender, but can be a range of colors in the red-purple-blue spectrum or white-pink, and can reach anywhere from three feet to a hundred feet (though with the use of support of another structure, vine-like).

They can be shrubs, trees, or vines.  Hydrangeas in the wild are naturally less floral and vibrant.  This difference is due to domestic breeding for vibrancy that has made them more elaborate in societal settings.

If you are interested in cultivating this gorgeous flowering flora at home, you might like some guidance or tips to help you.  Here is a list of tips for your hydrangea growing process.

Buy Hydrangea seeds on Amazon


These flora are mainly decorative.  They are used frequently in weddings and fabulous special occasions.  They are very popular, due to their visual appeal.


Plant in fall, or early spring season.  Early morning or late afternoon, for planting time of day.  They are said to grow quickly and fill out spaces in one warm season’s time.  When digging the whole for the plant root, make it two feet wider than the root and equal depth of it.

More hydrangea plants are fairly easily created by taking a long branch from one bush, bending it down to the ground, scraping to expose the internal of the stem part that touches the soil, and holding it there with a stone of sorts.  In time, the exposed stem will take root in the ground, forming a new independent plant.


Full sun in AM with partial shade in late afternoon hours is the ideal way to support your hydrangeas.  Though, partial shade all day will suffice their needs.


Rich, somewhat moist, porous soils are ideal for hydrangeas.  The porous souls are good at providing great water drainage for them.  This will keep them happy.  They also like a lot of organic materials in their soil; coffee grounds are a plus here, as well as egg shells, etc.

Hydrangeas can not stand to be sitting in standing water for long, so all that porous material increasing moisture flow will keep them happy.  Remember this especially if using a pot.  Add mulch and fertilizer to maintain porous nutrient rich soil.

Hydrangeas come in a variety of colors
Hydrangeas come in a variety of colors


Hydrangeas like to have moist soil and dry leaves.  Keep the soil somewhat evenly damp but not soppy.  They prefer to be well drained.  They are said to absorb water fast, so you’ll want to water about once every day or two, depending on the season.

One inch of water averaged each week is ideal for them; including three deep waters throughout each week.  The deep waters encourage the roots to grow down, deeper.  Ideally you’ll want to water them in the morning.

When it gets cold outside, watering them at night will be harder on them due to their limit on how low of temperatures they can handle comfortably.


Hydrangeas are USDA hardy to zone 7 (zero degrees Fahrenheit).  They like cool to warm, less than extreme temperatures.  So, basically any where in North America, these flowering plants should act like perennials coming back every year.

pH and Color

You’ll want to monitor your soil’s pH level, if you are interested in manipulating or controlling the color.

Depending on a) what type of hydrangea you get – white vs. colored, and b) what your soil pH level is, you will end up with a particular color.

  • For white hydrangeas, you cannot manipulate the color much, as there is none, except a slight hint of pink sometimes.
  • For color hydrangeas, the options are:  pH 5.5 and below = blue, 5.5-6.5 = purple, and 6.5 and above = pink.   Alkaline is considered pH 7 and above.  Acidic is pH 7 and below.  Zero is the lowest possible number, while 14 is the highest possible level.


If hydrangeas have a lot of room, you can let them simply spread and grow to take over the area.  If you don’t have a ton of room for them, you may like the look you get when pruning them occasionally.  This will help lift some of the weight from the heavy flower bundles so the plant sits a bit higher, more uplifted.

There are two types of blooms on hydrangeas.  You will have one or the other, depending on the variety you get.  One type blooms in early summer, then simply grows flower buds that then await till next summer to bloom.  And does this as an annual cycle.

Pruning Hydrangeas
Pruning Hydrangeas

The second type creates flower buds in early spring that bloom later in the summer following.  This information can help you know when you want to prune.

For instance, you can imagine the disappointment of a person cuts type two in mid summer… because they would not get any blooms that year.  Whereas in type one, the buds would be produced shortly after that and await till the next early summer to bloom, so it would be fine.

For type two (“new wood” type), pruning in late winter is ideal.  This gives the plant enough time to begin bud generation in the spring.  For type one (“old wood” type), pruning is ideal in late summer early fall.

This is around the time the bloomed flowers will start to fade into death, but just before the new buds are produced, which will bloom the next year’s summer.

To plant food, or not to plant food?

When it comes to marketed plant food, that should be fine to add to your hydrangeas.  It might even be a fun experiment to monitor how a particular one may or may not change the color of the flowers over the course of that warm season, while the flowers bloom.

You do not have to purchase this however.  If you are looking to save money and be resourceful (using what you already have on hand), simply throw vegetable scraps leftover from cooking, coffee grounds, and egg shells into the dirt which will provide a rich ecosystem there for insects, nutrients for the plant, as well as improving water flow downward, so the plants are not sitting in soppy mud.

Miracle-Gro Plant Food is perfect for Hydrangeas

Life Cycle

Flowers bloom early spring to late fall.  In very hot areas, they may stop blooming in the hottest point of the season, but then they start back up again soon after.

Careful in your variety choice, however – when living in extremely hot areas, as some do not do well in extreme heat.  They will lose their flower petals in the fall, but will come back again the next spring season.

Simply keep the soil moist year round and you should have no problem… unless it gets below zero Fahrenheit… then, you’ll be moderately lucky if they survive and come back the next year.

Diseases & Pests

Powdery Mildew affects bigleaf hydrangeas the most.  It appears as a white powder looking fungus on the top of the leaves.  Purple and yellow spots on the leaves may appear as well.

This disease is mostly aesthetically disruptive… but, being that this is often the main purpose of this plant… one can see how disruptive it can be.  Root Rot can kill the entire hydrangea plant.

Visual signs include progressive wilting and little white fan-shaped mycelia mats just under the bark at the stem-base near the soil-line.  Also, in fall season, after lots of rain, honey colored mushroom fungus appear in the soil above roots that have this.

Keeping your hydrangea in its proper habitat (correct soil, temperature, sun, moisture) are the best defense against this disease.

Blister rust,  and virescence, and bacterial wilt are some diseases that can harm your hydrangea.  Blister rust will be visible, in that it produces clusters of orange spores on the bottom side of its leaves.

Aphids are a pest (insect) that can grow to numbers that make it very uncomfortable for your hydrangeas.  They appear on new growth, more commonly.  They secrete a clear sticky sugar based liquid.  This can cause a black mold to grow on it.  The sugary substance may also attract ants.  The aphids themselves may also cause yellowing of the leaves, or distortion.

Hollie is a life-long gardener, having started helping her Dad work on their yard when she was just 5. Since then she has gone on to develop a passion for growing vegetables & fruit in her garden. She has an affinity with nature and loves to share her knowledge gained over a lifetime with readers online. Hollie has written for a number of publications and is now the resident garden blogger here at GardenBeast. Contact her at or follow on twitter

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