How to Care for Hydrangeas—Whether Potted, Planted, or in a Bouquet

Hydrangeas may be just about everywhere, but these pretty flowers take a little bit of care to grow into the big blooms you know and love. Whether they're in a vase, blooming in the backyard, or flourishing in a planter, these beautiful, lush blooms are classic. As with any flower, though, keeping up with hydrangea spring care is important—and so is what you do the rest of the year. These flowers certainly need their fair share of TLC. So pick up some trusty gardening tools and get ready to get your hands dirty—your hydrangeas will thank you.

Growing Conditions

Temperature and season

"The best time to plant hydrangeas is when temperatures are mild in spring and fall," says Ryan McEnaney, a spokesperson for Endless Summer Hydrangeas. "In spring, wait until you've passed your final frost and the ground is thawed enough to dig easily. In fall, be sure not to wait until late, when a frost could damage the plant." If you want to plant in the summer, avoid doing so on very hot and bright days. These blooms are at their peak in mid-summer through fall.

In the winter, hydrangeas need protection. "Add an extra layer of mulch, leaves, or pine straw up to 6 to 8 inches high to provide tender buds protection from drastic temperature changes, cold nights, and high winter winds," McEnaney says. "It's sometimes helpful for younger plants to add a cage to add more protection—and keep the bunnies out."

Soil

Hydrangea prefer moist but well-draining soil (not wet soil). The good news is that doesn't mean you can't grow them if your soil happens to be clay or sandy. "If you have clay soil that retains a lot of water, add gypsum or organic material to allow for greater growth," McEnaney says. "If you have sandy soil, adding composted material will help retain enough water and nutrients to keep your hydrangea healthy."

Water

These flowers love water—so you'll want to keep them hydrated. "One common misconception, though, is that they need constant water," McEnaney says. "You want to ensure that the soil is moist, but not wet. Overwatering can actually cause the plant to grow without flowers. It's better to give it a heavy soaking once a day (or whenever the soil needs it), preferably in the morning or early afternoon, than various applications of less water." To find out if you need to water the plant, stick your fingers into the soil about an inch or two deep to see if it feels dry or wet.

Fertilizer

If you live somewhere with good soil (moist), these flowers won't need much extra help. "To maximize blooms, a standard 10-10-10 fertilizer will give your hydrangeas some extra energy to produce more flowers," McEnaney says. To get the most out of your fertilizer, he recommends applying it (according to package instructions) right when leafy growth begins to emerge in the spring. "Be sure to put fertilizer under the entire drip line of the plant, meaning the whole diameter of where your branches reach," he says. Hydrangeas have shallow roots, so this will provide their whole root system with nutrients from the fertilizer.

Light

Hydrangeas grow best in partial shade areas. "Make sure that there is enough space for the hydrangea to grow into, that the soil is amended as needed, and that there is the proper amount of sunlight," McEnaney says. He recommends placing the hydrangeas in an area that gets about five to six hours of morning sun, followed by dappled (or patchy) shade. If you live in warmer regions, plant where the blooms can get two to three hours of morning sun and partial shade in the afternoon.

Types of Hydrangeas

The beloved blue-purple flowers are probably the first image to come to mind when you hear "hydrangea," but there are actually a ton of stunning varieties to choose from. Here are some of hte most common ones.

Smooth hydrangeas (hydrangea arborescens)

These flowers look like big white snowballs, which is why they're sometimes called snowball hydrangeas. They're naturally fast-growing and need very little (if any) fertilizer.

Panicle hydrangeas (hydrangea paniculata)

These are the most common type of hydrangea, and they are available in both shrub and tree form. "Panicle hydrangeas have cone-shaped blooms that emerge in early summer and change to varies shades of parchment, pink, and red as temperatures cool down in the fall," McEnaney says. Some common varieties are Berry White and Vanilla Strawberry.

Oakleaf hydrangeas (hydrangea quercifolia)

Like their namesake, the mighty oak tree, this variety of hydrangeas has lobed leaves. It's native to the southeastern United States and they bloom green then transition to white, pink, and brown. They also have a reddish-brown bark that naturally peels away.

Bigleaf hydrangeas (Hydrangea macrophylla)

Now these are the ones you probably think of first. They bloom in purples and blues but also whites, pinks, and reds. They have large blooming clusters (mop heads, as they're called) made up of big, bold leaves.

How to Grow Hydrangeas

Growing in the garden

First, start digging! "Dig a hole slightly larger than the pot your hydrangea came in, keeping in mind that you want to leave enough space in the garden for the hydrangea to mature to its full size," McEnaney says. "Add a small amount of high-phosphorus fertilizer to the bottom of the hole, then remove the plant from its container and slightly loosen the roots with your fingers. Place the plant in the hole, making sure that the crown of the plant (where the base of the stem meets the soil) is even with the ground level." After you put the hydrangeas in the ground, cover them with soil and water. Hydrangeas prefer loamy (mixture of sand and silt with a bit of clay) and moist soil, so make sure you frequently check it the first season or two to ensure that it isn't dry or soaking wet.

It's OK to cheat and buy a shrub from your local gardening center, instead of trying to grow your hydrangeas from seeds—especially since seeds are hard to come by. "If you're able to obtain seeds, you must sow or scatter the seeds in the soil, taking extra care until they're germinated," McEnaney says. "To get the same size shrub as you would in your local garden center, it could take two to three years."

Growing in pots

Caring for potted plants is slightly different than tending to a large garden bed. "Make sure that the bottom of your container has holes to allow excess water to flow through," McEnaney says. "If there's no drainage and too much water collects around the roots, it can prevent blooms from developing and cause the leaves to wilt." For pot size, it ultimately depends on how many hydrangeas you want to plant inside and if you want to use any other kinds of flowers. With larger containers, because they hold more soil and more water, you won't have to water them as frequently.

Use pre-mixed, bagged potting soil. "Fill the decorative container with potting soil, leaving roughly eight inches open on top," McEnaney says. "Place the hydrangea in the center of the container and fill with soil." Leave 1 inch of space between the soil and top of the container so nothing will overflow when you water the plant. If you have a larger container, you can also mix in other flowers for a colorful look.

Like in-ground hydrangeas, the ones in planters need a lot of water. To determine if your flowers need water, you can use the same method of sticking your fingers in the soil to gauge dryness. McEnaney says container hydrangeas might need more water since they're not established in the ground and have less soil to soak up the water from

Common Pests and Diseases

Many newer varieties of hydrangeas are bred to be resistant to pests and diseases (yay!). That being said, there are still a couple of things to watch out for, especially if you live in a harsh or humid climate.

Diseases

The first is cercospora leaf spot. "It's a fungal disease caused by moisture on the leaves that can produce leaf damage and look unpleasant," says McEnaney. Applying a fungicide and increasing airflow will help. Another issue: Powdery mildew. This is especially common in bigleaf hydrangeas. To fix this, McEnaney recommends disposing of the affected leaves to keep it from spreading.

Pests

Aphids and spider mites can cause damage to hydrangeas (it happens!). Spider mites weave a sort of web around the flowers and suck nutrients out of the plant. Aphids feed on the leaves and can cause yellowing. Both can be conquered with insecticide.

How to Care for a Hydrangea Bouquet

Examine the blooms for signs of damage.

When you're choosing your hydrangeas at the store, look for healthy, bright green leaves with bouncy blooms. "Check for any browning spots on the petals, which would indicate sun damage," says Callie Bladow, former production director at BloomThat. "Also, due to cold storage of cut flowers, keep an eye on dark petals which could indicate the blooms have touched the side of a refrigerator. You want a flowering hydrangea that feels sturdy and not soft or spongy." If you choose a healthy bouquet, it should last up to two weeks.

Cut garden-grown flowers with a sharp floral knife.

If you're lucky to have garden hydrangeas, it's easy to bring them indoors for a beautiful arrangement. Using a sharp floral knife or clean kitchen shears, cut them on a bias (a 45-degree angle) and place them in a bowl of lukewarm water while you're working outside. "The best time of the day to cut your hydrangea blooms is in the morning," Bladow says. "Choose the most mature and full-looking blooms and leave the others to keep blooming. Fully-bloomed hydrangeas will look more 'papery' than the young-budded blooms."

Prep them with alum powder.

Hydrangeas produce a sap at the bottom of the stems that needs to be sealed off so they can soak up water. "After you cut the stem on a bias, dip the stem in alum powder, which is an onion powder that you can pick up at your local grocery store in the spice aisle," Bladow says. "All it takes is a simple dip of the bottom of the stem, and then straight into the vase." If you don't have alum powder, you can dip the stem in boiling water for about 10 seconds, which will produce the same effect. Also, remove the leaves from the stem since they'll hog all the water in the vase.

Get creative arranging with different flowers.

You can go with a classic all-hydrangea flower arrangement, or experiment with mixing in different flowers or using unique vases. "I love using glass apothecary jars that have larger bases and small vase necks," Bladow says. "The other way that we love designing with hydrangeas is to use them as grids for other flowers. There are multiple stems on the hydrangea head that keep other flowers secure, so just stick them into the flower head." You can arrange hydrangeas with all types of flowers—she recommends roses, dahlias, and freesia, with some greenery like lemon leaf or variegated pittosporum.

Change the water daily.

"Hydrangeas like cool water and it should be changed every other day with a fresh snip of the stems," Bladow says. "You can add in a little flower food or simple cane sugar from your pantry in the vase." Make sure to keep your arrangement out of direct sunlight. And if your flowers are looking sad, Bladow suggests soaking the entire hydrangea in cool water for about 45 minutes. Shake them off, cut the bottom of the stem, and place them in water with flower food. It might help revive your hydrangeas and increase their shelf life.