For hydrangeas to change from pink to blue, the soil must be acidic and contain salts of either aluminum or iron.
We all learned in chemistry classes in school that distilled water has a neutral pH of 7. However, in horticulture, a neutral pH is typically categorized as 6.5. Any soil with a pH below 6.5 is considered acidic, and any soil with a pH above 6.5 is considered alkaline. A pH testing kit can be used to check the pH of your soil, and Greenshutters Nurseries & Garden Centre has these on hand. The inexpensive pH meters that are available are often not precise, so I do not advise using them. Often, seeing surrounding gardens and the local plant life is a simpler approach. It’s likely that your soil is acidic if nearby Rhododendrons, Camellias, and Pieris are flourishing in the soil.
Peaty or sandy soils are typical of acidic soils. Clay soils are typically not highly acidic. Chalky soils have a high pH. By incorporating Irish moss peat or ericaceous compost, you can increase the acidity of your soil. Ericaceous compost has an acidic pH range of roughly 5.0 to 5.5, while regular multifunctional compost has a pH range of 6.0 to 6.5.
Irish moss peat is particularly useful for mulching since it has a pH of about 4.0, which is much too acidic for most plants to thrive in. However, when combined with neutral or alkaline soil, it lowers the pH of the soil. Once a year, mulch with Irish moss peat and let the worms to work the peat into the soil to maintain the acidity of the soil around a plant.
As an alternative, hydrangeas can be grown in containers. Although hydrangeas can thrive in both multifunctional and ericaceous compost, it is recommended to plant them in the latter if you want them to turn blue.
If your soil is deficient in aluminum or iron salts naturally, you can easily increase them by putting Hydrangea Colorant into the soil. People claim that adding rusty nails to the soil or compost will turn hydrangeas blue; however, as I have never tried it, I am unable to confirm if this is true or false. On the other hand, Hydrangea Colorant is a combination of Iron Salts and Aluminium Sulphate. When potting or planting, it can be added to the soil. For established plants, you can also dissolve the Hydrangea Colorant in water and give your hydrangeas a weekly drink during the growing season (March to September). Your light pink kinds will become blue if you do this, while your dark pink varieties will turn mauve-blue.
Grow your hydrangea in neutral or alkaline soil, though, if you want it to stay pink.
Does ericaceous feed help hydrangeas?
Ericaceous compost, which increases soil acidity and influences hydrangeas’ bloom color, is beneficial to acid-loving plants like hydrangeas.
This particular compost is an easy approach to modify the alkaline soil in your garden or planters if it is currently that way. I’ll discuss the best ericaceous composts for hydrangeas and show you a simple method for adjusting the soil’s pH level so that it is more acidic and suitable for hydrangeas.
The ideal compost for hydrangeas is…
An inadequate diet may make a Hydrangea’s style difficult. However, if you’re the type of gardener that favors natural techniques, you might be thinking whether all of those specialty fertilizers you see online are actually necessary. Can you use compost or other natural fertilizers to grow hydrangeas?
Yes, it is the answer. Compost, whether purchased or prepared at home, will help hydrangeas grow and thrive since it is nutrient-rich and improves soil drainage. Most Hydrangeas respond well to all-purpose compost, but ericaceous compost is preferable if you want your Mopheads or Lacecaps to produce blue flowers.
The fact that you can make compost in your own backyard is arguably its best feature. Simply gather the ideal mixture of kitchen and grass scraps and spread them out for your neighborhood worms and microorganisms. Your hydrangeas will receive a ton of nutritious yield from them.
Are hydrangeas plants that love acid?
Although they can also be grown in neutral soil, hydrangeas appear to all prefer acidic soil. They can even tolerate somewhat alkaline soil, but if your garden soil has a naturally high pH level, it is best planted in ericaceous soil in containers.
Hydrangeas are typically white, pink, or blue. Acidic soil will cause pink hydrangeas to become blue. On the same bush, you might have a gorgeous dazzling display of pink, lilac, and blue flowerheads.
The greatest places to grow hydrangeas are in regions with high rainfall since they adore water.
Which compost is best for potted hydrangeas?
According to John Negus, a garden expert for Amateur Gardening, “the ideal potting compost for shrubby plants is one with a high concentration of loam, such as John Innes No. 3.” The RHS (opens in new tab) suggests combining two parts of John Innes No. 3 and one part peat-free multipurpose compost for hydrangeas. Use an ericaceous compost as an alternative if you are growing blue hydrangeas and want to maintain the vibrancy of their color.
Even the best multi-purpose composts, according to John, “only have adequate nutrients for four to six weeks of growth, and after this is expended, plants will need supplemental feeding, either with a liquid or by top-dressing with controlled-release fertilizer.” From early summer to the end of flowering, feed with a liquid or top-dress in the spring.
John continues, “Loam-based composts retain moisture better than peat-based ones.” All potted plants, however, require constant watering because their roots are restricted and their compost is hidden by foliage, unless it rains heavily every day.
Do all plants benefit from the usage of ericaceous compost?
Compost that is specifically designed for growing ericaceous plants is an acidic sort of compost. These can include plants that do poorly in alkaline soil, such as heathers (the word “ericaceous” is derived from the Latin word for heathers), camellias, and rhododendrons.
Do hydrangeas require specific types of soil?
In dappled shade that is neither very sunny nor overly dark, wet, well-drained soil is excellent for hydrangeas. Avoid sites that face south, especially if the soil is quite dry. Grow Hydrangea anomalasubsp. petiolaris, a climbing shrub, in an extremely shady area like a north-facing wall. Avoid planting in a frost pocket and plant away from strong winds in the spring since the tender new growth is vulnerable to frost damage.
Most soil types, including alkaline and acidic soil, are suitable for hydrangea growth. The color of some types’ flowers will vary depending on the pH of the soil. If the soil is acidic, some plants that typically produce pink flowers will instead produce blue ones.
When to plant hydrangeas
Hydrangeas grow best in the spring or fall when the soil is warm and moist. It is possible to plant in the summer, but you must monitor the soil’s moisture content.
How to plant hydrangeas
If your soil is thin, bulk it up with moisture-retaining organic matter before planting hydrangeas because they thrive in damp soil. A good hour or so before planting, thoroughly water the plant. A hydrangea should never be planted any deeper than it was in the pot. Well with water. After planting, add a layer of mulch. Leaf mould is preferable, but compost or well-rotted manure can also work. Throughout the plant’s first spring and summer, make sure it gets plenty of water.
Train climbing hydrangeas initially onto galvanized wires before planting. They have roots that attach to themselves, so after a season of growth, they will find their own way.
Watch this Gardeners’ World video to learn how to plant lacecap hydrangeas:
How can acidic soil be created for hydrangeas?
Like coffee itself, coffee grounds have an acidic pH. The acidity of the soil around hydrangeas is increased by mixing in dried coffee grounds, which enhances the hydrangea’s capacity to produce blue and its capacity to absorb aluminum from the soil. With a pH test kit, track the soil’s pH over time; a range of 5.2 to 5.5 is ideal for blue flowers. Coffee grinds occasionally scattered on the soil’s surface or placed there will slightly raise the acidity level.
Are hydrangeas better in the ground or in pots?
Maintaining hydrangeas in pots is easy, and they provide a beautiful addition to a deck or patio’s color and structure. Additionally, they go well with modern gardens as well as country gardens.
You already know that hydrangeas want moist, organically rich soil that doesn’t dry out over the summer if you’ve read up on how to cultivate them. They thrive best when planted directly into the ground because containers have a tendency to dry out much more quickly.
But that doesn’t mean you can’t use these blooms to make a lovely container arrangement. Simply make sure to take good care of them, choose your compost wisely, and plant them where they will thrive. Additionally, some kinds are better suited to these circumstances. Everything you need to know about taking care of hydrangeas in pots is included in this guide.
What kind of potting soil works best for hydrangeas?
We automatically think of huge plants when we think of hydrangeas because of their enormous foliage and larger-than-life blooms. However, hydrangeas actually come in not one, not two, but three sizes!
Regardless of the size of your area, locate the ideal hydrangea. Even hydrangeas can be grown in a container.
1. Small Is Everything. Choose a hydrangea that will grow well in your restricted space. Dwarf variations are small yet mighty little beauty. To select the ideal dwarf hydrangea for you, browse our Hydrangea Variety Guide. Then, locate a location that has the appropriate level of illumination.
2. Bold, large, and riddled with holes To create a statement, choose a pot or repurpose a container. Ensure that it has drainage holes alone.
3. Gold Soil Solid. Choose a high-quality, organic potting soil for hydrangeas because they require well-draining soil to thrive. If it possesses Myco-toneTM mycorrhizae, which use 30% less water than conventional soils, it gets bonus points.
5. Decide on the necessities. Water hydrangeas in containers when the top inch of soil becomes dry or when the plant starts to wilt. Feed your hydrangeas once a year in June or July with an organic fertilizer for the finest hydrangea care. Feed your hydrangeas with Holly-tone if you want them to be blue.
Big blossoms in a small space! Just picture how beautiful your hydrangeas will appear at your Memorial Day party shimmering in the sun or glimmering in the moonlight at your summer garden gatherings!
Which types of soil do hydrangeas prefer?
Hydrangeas have huge bloom heads and exude an old-fashioned elegance. How to plant and take care of beautiful floral bushes is explained in our hydrangea growing guide. Additionally, learn the answers to frequently asked questions like “why aren’t my hydrangeas blossoming this year?”
About Hydrangeas
These elegant plants are simple to grow, withstand nearly any sort of soil, and produce an abundance of blossoms that are unmatched in the world of shrubs for their stunning flowers. Clear blue, vivid pink, frosty white, lavender, and rose blossoms sometimes grow on the same plant, enticing us with their colors.
From container gardens to shrub borders to group plantings, hydrangeas are great for a variety of garden locations. Breeders seem to give us more possibilities every year, and gardeners have countless expectations for bloom size and color. Varieties abound. Pay attention to the species listed below to get an idea of how your hydrangea will develop as some require different maintenance. The joys you experience will be enhanced when you know what to expect.
Enjoy this tribute to hydrangea beauty and read our guide below to discover how to grow hydrangeas.
Where to Plant Hydrangeas
- The majority of hydrangeas like fertile, moisture-rich soils that drain well. Compost can help improve bad soil.
- Hydrangeas typically prefer some sun. In an ideal world, they would receive full sun in the morning and then some afternoon shade to avoid the intense midday sun. The Bigleaf Hydrangea (H. macrophylla), with its huge, prone-to-wilting leaves, is a prime example of this. Some kinds can withstand more direct sunlight.
- Depending on the kind, place hydrangeas anywhere between 3 and 10 feet apart. Plants should always be spaced according to their anticipated mature size!
When to Plant Hydrangeas
- The optimum season to plant hydrangeas is in the fall, followed by spring. The cooler shoulder seasons are the ideal times to plant shrubs because they will have plenty of time to build a strong root system before the intense heat of summer or the bitter cold of winter.
- In the early morning or late afternoon, plant the shrubs. The plant is less prone to experience heat stress from direct sunshine because it is typically cooler.
How to Plant Hydrangeas
- Gently remove the hydrangea from its container and examine the root ball. Snip off any rotten or dead sections, and if the plant is very root-bound, pry the roots free.
- Make a hole that is two to three times as big and as deep as the root ball. The top of the planting hole should be level with the base of the plant, which is where the stem joins the earth.
- After placing the plant in the hole, add enough soil to fill it halfway. generously hydrate. Fill the remaining space in the hole with soil once the water has been absorbed.
- once more, thoroughly rinse.
How to Grow Hydrangeas from Cuttings
Cuttings of hydrangeas can be easily grown. They easily take root, and the process is a wonderful teaching tool for propagation. This is how you do it:
- Find a branch on a mature hydrangea that is fresh growth and has not flowered. In comparison to older growth, new growth will appear lighter in color, and the stem won’t be as firm.
- Make a horizontal incision 4 to 5 inches down from the branch’s tip. Make sure your cutting has at least three to four pairs of leaves.
- Trim the cutting’s lowest pair of leaves so that they are flush with the stem. If you can afford to remove more than one pair of leaves, do so. Roots develop more readily from these leaf nodes. But make sure to leave at least two pairs of leaves at the cutting’s tip.
- Remove the tip half of any leaves that are still pretty large by cutting them in half. This keeps the leaves from slamming into the sides of the plastic bag you’ll later use to cover the cutting (to keep the humidity up).
- (Optional) Sprinkle rooting hormone and a plant antifungal powder on the stem’s leafless area (both available at a local hardware or garden store). This will promote roots and deter decay.
- Prepare a small pot and put moistened potting soil inside. The cutting should be planted in the ground, buried down to the first remaining pair of leaves. Lightly water the area surrounding the stem to close any air spaces.
- Wrap a plastic bag loosely around the entire pot. To prevent the cutting’s leaves from rotting, make sure the bag is not touching them. The bag can be supported by chopsticks or other such objects to keep it off the leaves.
- Put the pot in a warm location that is protected from the wind and sun.
- Only rewater your cutting after the top layer of soil is dry after checking on it every few days to make sure it isn’t decaying. In a few weeks, hopefully, the cutting will start to root! If you feel resistance when you gently tug on the cutting, roots have grown.
Watering
- Make sure hydrangeas get enough water for the first year or two after planting and throughout any droughts.
- Over the course of the growing season, water at a rate of 1 inch per week. Three times a week of heavy watering is preferable to shallow watering. Root growth is promoted by this.
- All varieties of hydrangeas benefit from constant moisture, but bigleaf and smooth hydrangeas need more water.
- If the soil is too dry, the leaves will wilt, and there won’t be enough moisture for the flowers to bloom.
- To water thoroughly while keeping moisture off the flowers and leaves, use a soaker hose.
- The best time to water hydrangeas is in the morning to protect them from disease and get them ready for the heat of the day.
- Under your hydrangeas, spread organic mulch to help keep the soil cool and moist, gradually add nutrients, and enhance soil texture.
Fertilizing
You might not need to fertilize hydrangeas if your soil is rich. When fertilizer is applied in excess, blossoms are sacrificed in favor of green growth. A soil test is the most effective tool for determining your fertility requirements.
Apply fertilizer according to the type of hydrangeas you have. Every variety has varied requirements and will profit from applying fertilizer at various times.
- Several mild fertilizer applications in March, May, and June are beneficial for bigleaf hydrangeas.
- Two applications in April and June work best for oakleaf and panicle hydrangeas.
- The only time smooth hydrangea plants require fertilizing is in the late winter.
Winter Protection
- Cover plants with bark mulch, leaves, pine needles, or straw in the fall, at least 18 inches deep. If at all feasible, create cages out of chicken wire or snow fencing and cover the entire plant, including the tip, with the cages. (Avoid using maple leaves; they have a tendency to mat after becoming wet and may suffocate the plant.)
How to Prune a Hydrangea
Many of the queries from readers concern hydrangea trimming. It makes sense that it’s unclear because it relies on the hydrangea kind. Fortunately, identifying which type you have makes determining the best pruning strategy simple. Discover the fundamentals below, then read more about pruning different varieties of hydrangea here.
Pruning Common Hydrangeas
The Bigleaf cultivar of Hydrangea macrophylla is the most popular garden hydrangea shrub. (For more, see below.)
Hydrangeas with large leaves, such as Bigleaf (H. macrophylla), Oakleaf (H. quercifolia), Mountain (H. serrata), and Climbing (H. anomala subsp. petiolaris), are pruned AFTER the summer blooms have passed. On stems from the previous season, these kinds bloom (“old wood).
- Avoid pruning after August 1 since flower buds actually grow in the late summer and bloom the next season.
- Dead wood should only be removed in the fall or very early spring.
- To stimulate branching and fullness, trim one or two of the oldest stems by cutting them all the way to the ground.
- Pruning the stems all the way to the base is necessary if the plant is old, neglected, or injured. For the following season, you’ll lose the flowers, but you’ll also revive the plant for subsequent ones.
- The huge Mopheads should not be deadheaded (faded flowers removed); instead, you should leave them over the winter and trim them back in the early spring (to the first healthy pair of buds). Deadheading Lacecaps is OK; simply trim down to the second set of leaves below the bloom head.
- Avoid pruning unless it is absolutely required while growing H. macrophylla (and H. serrata) cultivars in Zones 4 and 5, and then only after blooming. If not, merely remove dead stems in the spring.
Pruning Other Hydrangeas
Hydrangeas called Panicle (H. paniculata) and Smooth (H. arborescens) are clipped BEFORE flower buds develop. On stems from the current season, these kinds blossom (“new wood).
- When the plant is dormant in the late winter, prune. The plant will therefore grow new buds in the spring that will result in blossoms even if the winter kills the buds.
- In general, avoid pruning to “shape the bush” and just remove dead branches.
