With their huge spherical or panicle blooms, hydrangeas make your yard stand out. Since Idaho’s soil ph is too high for hydrangeas to thrive, we always plant sun- or shade-loving hydrangeas with acid planting mix. If you have planted without amending your soil or need to acidify your soil to keep your shade hydrangea’s blooms blue, add soil sulfur twice a year. We also add sulfur to our soil to help the pH be more favorable.
The hydrangeas in our shadow house may grow in morning sunlight up until noon or one o’clock in the afternoon before needing shade. Near our roses, in full sun, you may observe hydrangeas that will flourish with six or more hours of sunlight each day. When Idaho’s temps hit 80 degrees or higher, all hydrangea kinds require additional water, so be prepared to use your hose in addition to your sprinkler or drip system. A minimum of two 2 gallon drip emitters, one on each side of the plant, are required for most hydrangea. Make sure the time and frequency are increased when our daily highs are 80 degrees or higher by checking your sprinkler/drip settings.
What climate zone do hydrangeas prefer?
The hydrangea, which blooms in the spring and summer, is classified as a shrub. Despite the fact that they can grow to be pretty enormous showpieces in your yard, even a beginner gardener won’t need to know how to grow hydrangeas because these stunning plants practically grow themselves. The hydrangea, which can grow up to 15 feet tall, fills in a space swiftly and frequently in just one summer. Hydrangeas are perennial plants that grow in hardiness Zones 3 to 7. Hydrangea blooms can be the main plant in your landscape because they bloom in the spring and frequently continue into the early fall.
Which shrubs thrive in Idaho?
Native Plants of Idaho: 11 Spectacular Plants from the Gem State
- flax, blue (Linum lewisii)
- Mountain rocky maple (Acer glabrum)
- Coneflower with a green head (Rudbeckia laciniata)
- Typical yarrow (Achillea millefolium)
- Royal cup lily (Clintonia uniflora)
- Bright star (Liatris spicata)
- Milkweed (Asclepias syriaca)
Can you find hydrangeas in southern Idaho?
How to Find an Idaho Hydrangea Idaho definitely isn’t the first place that springs to mind when you think of growing hydrangeas, but you probably didn’t know that the whole bulk of Idaho is well inside the ideal growing zones for hydrangeas.
Do hydrangeas like shade or the sun?
With the ideal balance of morning sun and afternoon shade, hydrangeas flourish. Even the sun-loving Hydrangea paniculata will thrive in some shade. Some hydrangea cultivars may survive complete shadow, though.
The oakleaf hydrangea, also known as hydrangea quercifolia, is a substantial species of hydrangea that may reach heights of up to eight feet. In a shade garden, this big bush makes a beautiful backdrop. The height will provide excellent midsummer seclusion. Oakleaf hydrangeas are summer bloomers with mostly white blooms, elegant oakleaf-shaped leaves, and lovely peeling bark.
Hydrangea anomala ssp. petiolaris is another choice for full shade. This climbing species, which has lacy, white blossoms in the summer, can reach a height of 50 feet if it is given adequate support. The foliage is a rich shade of green and would look wonderful growing up a tree trunk or covering the face of a building. It would also look lovely covering the roof of a garden shed.
Full shade cultivars require the same upkeep as partial shade. In the deeper shade, it will be especially crucial to keep the plants free of leaf litter and with excellent airflow. Water your plant once a week after it has become established. Keep a watch on the leaves, and if you notice any drooping, especially during the hot summer months, water them right away. The importance of this increases in hotter regions.
These leaves’ unique shape would be a lovely complement to Hosta leaves. The white blossoms would contrast nicely with the lighter hues of your shady blooms and provide some brilliant brightness to your shaded locations.
Shade Varieties
There are a few different hydrangea cultivars that thrive in the shade. Some types can even thrive in zones 3 (which doesn’t warm up until later in the spring), which is one of the coldest growing regions. Let’s examine some of the best shade selections!
Hydrangea quercifolia ‘Snow queen’
The movie “Snow queen” is stunning. The flowers are stunning, as they are with all hydrangeas. These rose blush-colored blossoms appear in the middle of summer. The foliage of this plant is my favorite component. The leaves begin the season in a very deep green, gradually changing to a deep reddish bronze color, and finally finishing in that shade, offering a stunning splash of color to your fall landscape.
Hydrangea quercifolia ‘Alice’
With a height ranging between 12 and 15 feet, this Oakleaf Hydrangea is one among the biggest. In the summer, this plant blooms with incredibly deep cream-colored flowers. A woodland garden would be a truly lovely place for “Alice.” This cultivar would look especially beautiful if it were grown as a bordering hedge.
Hydrangea arborescens ‘Annabelle’
‘Annabelle’ enjoys partial shade and has some of the largest flowers in the hydrangea family (12 inches wide!). These enormous blossoms can be supported all season long by the sturdy stalks. This shrub can grow up to five feet tall and five feet broad, so give it plenty of area to expand. These enormous, all-white blossoms bloom for a long time.
In a mass planting, as a specimen shrub, or as a foundation planting, “Annabelle” would look lovely. These bushes should still be included in your cutting garden. Imagine a bunch of flowers that large! Wow!
Can I put my hydrangea plant in a pot outside?
Mophead hydrangeas can be cultivated outside wherever the wintertime temperature stays above -15oC because they are hardy (5oF). However, as they were grown in greenhouses and given fertilizer to induce early flowering, potted hydrangeas sold as houseplants may require some time to acclimate to life outside before being put out. Place them outside in their pots during the day and bring them inside at night to harden them off for one to two weeks before to planting. Hydrangeas that have been grown for outdoor planting can be planted immediately. Mid- to late April, when the soil has had time to warm up, is the ideal time to plant mophead hydrangeas outdoors.
The optimal conditions for hydrangeas are shade from the sweltering afternoon sun and moist, well-drained soil. They are therefore excellent alternatives for shady gardens, and in mid- and late-summer, their dramatic spherical flowerheads are absolutely gorgeous. Regularly water hydrangeas, especially during dry spells, and in the spring or fall, mulch with compost or other organic material.
Because of the soil’s pH (acidity or alkalinity), pink and blue mophead hydrangea blossoms have the unusual ability to change color. The blossoms will be a deeper shade of blue the more acidic the environment is. Flowers turn a gorgeous pink on alkaline soil. The color of white mophead hydrangeas doesn’t alter.
What temperature is too low for hydrangeas?
Many people were dissatisfied last year because their hydrangea shrubs produced few, if any, flowers. It was assumed that the particularly hard winter was to blame.
There are numerous hydrangea species, but the majority of them that are grown by homeowners in their gardens belong to the genus Hydrangea macrophylla.
The two groupings of H. macrophylla are distinguished by the appearance of their flowers. The mopheads have a broad, rounded shape and can range in color from red to pink to white to blue to green and many colors in between. Similar in color, the lacecaps are flattened corymbs with fertile blooms in the center and spectacular clusters of sepals of various sizes around them.
Hardiness zones 6 to 9 apply to H. macrophylla. A hydrangea should, in theory, be able to withstand temperatures as low as -10 degrees. However, in the real world, temperatures as low as 12 degrees and freezes in the late fall or early spring may limit this hydrangea’s ability to flower.
H. macrophylla forms its bloom buds in the summer and the fall in response to the shorter days and chilly temperatures. To achieve bud dormancy, the bud must be refrigerated for 1,000–1,200 hours, or roughly seven weeks.
As the weather gets warmer, buds open, shoots appear, and blooms grow. Flower buds and vegetative stems will perish if this happens at the end of February, as it did last year and may do this year as well. In the spring, the plant might grow again from the root, but it won’t produce flowers. It has sturdy roots, but delicate flower buds.
On fresh wood, on the woody stems from the current year, H. macrophylla flowers. If a shrub needs to be pruned, it should have been done last year when the blooming season had just ended. Avoid pruning it. You will now remove any budding flower buds.
I have been growing my favorite variety of H. macrophylla for almost 15 years, and it is called “Blue Billows.”
Dr. Richard Lighty of the Mount Cuba Center in Hockessin, Delaware, originally grew this lacecap, Hydrangea serrata, from seed gathered in the Korean mountains. The inner fertile flowers are a darker blue than the outer sterile blossoms, which are blue with a pink blush.
Before relatively recently, the taxonomists classified the H. serrata variation as a distinct species from the macrophylla. It possesses each of the traits that distinguish H. macrophylla from other species. The leaves are smaller, though, and it has a stunning copper-red fall color. From June to October, the plant blooms; as fall approaches, the blossoms turn over to reveal pink undersides.
It is situated for me in some moderate shade with drained soil. They call it a “robust plant.
Most recently, the big root ball split in two when I moved it to a shadier spot. I then discovered that it had sucker-grown or air-layered three smaller plants.
It is a dense shrub that grows to be about 3 feet tall and wide, and it is so covered in leaf and flowers that I was unaware I had four additional plants until I started to move it.
This low-maintenance shrub works well as a border shrub or as a foundation plant. And it will offer you profusion that you can keep or gift to others as a reward. It was chosen by the Pennsylvania Horticulture Society in 1990 as a Gold Medal Plant.
Depending on the amount of aluminum ions in the soil, the color of the flower varies. In more acidic soils, the concentration is higher, whereas in more alkaline soils, it is lower. For the majority of H. macrophylla and H. serrata cultivars, acidic soil (pH 5.5 and below) will result in blue flowers, whereas neutral to alkaline soils (pH 6.5 and higher) will typically result in pink flowers. The blooms will be purple or a combination of blue and pink blossoms will be seen on the same plant between pH 5.5 and pH 6.5.
The most constant guideline for growing hydrangeas, though, is that there is a lot of variety and no absolutes.
At this time of year, Hydrangea arborescens is another hydrangea that merits discussion. It also appears as lacecap and mophead flowers. The names “Annabelle,” “Invincible Spirit,” and “Grandiflora” are a few well-known cultivars. All of these flower on fresh wood. Cut them to the ground now, in late winter, and apply a mild fertilizer.
Place a support structure around the plant before it starts to grow since the flowers are frequently too heavy for the stems to keep the plant upright.
The new plant will start to bloom in June or July and continue to do so for several weeks.
As the petals wilt, cut the stem at the base and remove the leaves if you want to dry them. Cut them to the length you want, then hang them backwards. They make wonderful dried flowers and can be sprayed with spray paint to add color.
Are hydrangeas winter hardy?
Here is professional guidance on how to put hydrangeas to bed for the winter season from guest bloggers Megan Nichols and Jessie Jacobson of Tonkadale Greenhouse in Minnetonka, Minnesota. (They may have more hydrangea trees and shrubs in their zip code than almost anywhere else in the United States, so they are aware!)
The temperature has dropped, and autumnal symbols can be seen everywhere. The garden needs to be put to bed soon. Hydrangeas reward us with large, stunning, and prodigious blooms all season long. You may say that they are givers. It’s time to return the favor now. It’s time to tuck the hydrangeas in with kisses and wishes for sweaty dreams.
Here in Minnesota, our moods can fluctuate as drastically as the unpredictably harsh winter weather extremes, snowfall, and freeze/thaw cycles. Despite the fact that many hydrangeas are regarded as hardy, all of this can confuse them. To survive the winter and come back bigger and better the next year, they require some care. Although hydrangeas cultivated in warmer areas don’t need as much post-season primping as those grown in our zone, there isn’t a single thing that wouldn’t appreciate a little tender loving care right now.
Utilize these suggestions to get the most out of your hydrangeas so that you can be the one to present at this time next season!
(Is pruning in order? No and yes. Here is our recommendation for which hydrangeas should be pruned right away and which should wait until spring.)
Don’t Stop Watering
Make a commitment! I shall water my hydrangeas till the earth freezes solid, you declare while raising your right hand. really good Hydrangeas are thirsty plants by nature, so it’s essential to give them regular, deep watering. We don’t need to get all linguistically nerdy right now, but their name literally means “hydration.” Winter’s cool, dry winds completely drain the moisture from the vegetation, and hydrangeas don’t use lip balm. It need not be heated in order to be dry!
If a freeze is not a concern where you live, water deeply but sparingly during the winter depending on how much rain you get.
This is how: Making a small hole in the side of a 5-gallon bucket, filling it with water, and placing it at the base of the plant while it slowly drips out of the bucket is one method. Another option is to lay your hose at the base of the plant for about an hour with the water turned on to a gentle drip.
Give Them One Last Hearty Meal
Composting your hydrangea beds in the fall will give them a boost for the upcoming growing season. Everyone feels better after a full night’s sleep and a filling breakfast. This also applies to hydrangeas. After a lengthy winter’s hibernation, they will be ravenous for some nice compost. Compost can decompose during the winter if it is used now, making nutrients easily accessible in spring. A few inches of compost is advisable even in regions without a deep cold. Only compost is being discussed here! Don’t give your hydrangeas fertilizers that are high in nitrogen because this can encourage them to produce new foliage growth.
This is how: Before laying down mulch in colder climates, top dress the area with compost, well-aged manure, or other organic material after the ground has frozen. This organic fertilizer, which is rich in nutrients, will decompose over the winter, making nutrients available to the plant in the spring. Apply compost in the late fall or early winter in zones that are warmer.
Mulch Matters
Mulching helps keep moisture in and weeds out in warmer climates while shielding the crown and roots of your hydrangeas from harsh winter temperatures in colder climates. Snow serves as a natural insulator if everything goes as it should. Plants suffer during strange winters with little snowfall and extreme temperature changes. Apply a thick layer of mulch around the plant’s base to offer hydrangeas the best chance of flourishing. While decorative mulch is useful, straw, marsh hay, or dead leaves are suggested instead.
This is how: Apply a 6–8 layer of mulch once the ground has frozen (or late fall or early winter in zones with milder winters). This shields plants from the heave-ho of springtime freeze/thaw cycles, which can yank them out of the ground. Inviting mice to make this their snug winter home, causing rotting and illness, or tricking the plant into believing it’s time to bud, are all consequences of mulching too early. Be patient; you don’t have to do things early simply because your neighbors are.
Keep Them Cozy
The amount of winter cold determines whether or not hydrangeas require protection. Winter protection is not required in zone 7 if the air temperature stays above zero degrees. Wrap or totally cover barely hardy hydrangeas in chilly areas. This is crucial for plants that bloom on old wood, such hydrangeas with mop heads and large leaves (Hydrangea macrophylla). The most recent types of mop head/big leaf hydrangeas, however, bloom on both fresh and old wood, so it’s important to keep that in mind. In their favor and ours! Hardier hydrangea varieties like the paniculata and arborescens don’t often require additional winter care, although really low temperatures might cause its limbs to die back. Consider covering if a colder than usual winter is forecast.
This is how: Wrap plants loosely in a few layers of burlap, making sure to tie it off with strong twine. Making a mulch mountain and covering the majority of the plant is an additional choice. Smaller, newly planted specimens respond well to this technique.
There’s Still Time To Plant!
The first three varieties of hydrangeas can be grown here in Zone 4; oak leaf hydrangeas can also be grown in warmer climates (zones 5 to 9). The optimal time to plant shrubs is in the fall. Just make sure to do all of the aforementioned things, including watering and mulching.
Here are some of our favorites that you can plant now for stunning blooms the following spring.
Panicle Hydrangeas
These late blooming hydrangeas, sometimes known as PeeGee hydrangeas (summer into early fall). They are covered in elongated, conical flower heads that emerge white or green and blush into pinks and peaches as the season goes on.