Everything You Need to Know About Hydrangea Light Requirements for Optimal Growth
Besides healthy soil and adequate watering, there’s one other major factor to consider in the overall health of your hydrangeas: Light. If you’ve only recently added hydrangeas to your summer garden, then it may come as a surprise as to how little light they actually need to be happy in a garden—and the ways in which too much direct sun can actually harm them by scorching their leaves.
While plants like lavender and mint can take hours upon hours of scorching sun, hydrangeas fall somewhere on the other end of the spectrum—enjoying some direct light, lots of indirect or dappled light, and plenty of shade. How much light is too much when it comes to keeping your hydrangeas happy? We’ll cover everything you need to know about how much light your hydrangeas need to thrive.
The Role of Light in Plant Health and Development
You’ve likely heard that plants need sunlight to survive, and adequate light is indeed crucially important when it comes to having happy plants. The reason being that light is an essential component of photosynthesis—the process by which plants use sunlight to synthesize foods from carbon dioxide and water.
Without enough sunlight, most plants won’t even survive, let alone thrive enough to do all the other amazing things they can do—like bearing flowers, creating fruit, and building new root systems and fresh shoots.
But what you may not have heard before is that not all light is created equal or equally beneficial to all plants. Take for example Mediterranean plants like thyme and lavender. These plants thrive in hot, direct sunlight and likely won’t produce a bountiful harvest without it. But the light requirements of a hydrangea are different from those of a lavender. Whereas lavender likes full sun, hydrangeas are much happier in the understory of a garden—tucked at the edge of a tree canopy where they can be protected from the hottest sunlight and still receive plenty of indirect light.
Types of Light Explained
You’ll often hear gardeners talking about ‘types of light’, which can be confusing if you weren’t aware of any differences in light and how it’s used by plants. Light is often categorized for gardening purposes by two defining factors: duration and time of day.
The first category includes descriptions of light like ‘full sun’ or ‘part shade,’ which basically accounts for the number of hours of sunlight a plant receives. Depending on your location and altitude, full sun can mean anything from four to six hours of direct sunlight per day, with half of that number generally being used to describe part-sun or part shade gardens.
The second category describes what time of day your plants receive sunlight. This is a surprisingly important distinction to make since morning sun tends to be gentler than midday or afternoon sun, and a plant that does well in one may not equally benefit from the other.
Hydrangea Light Requirements
Now that you know a bit about the general types of light let’s dive into the specific light requirements of hydrangeas. Depending on where you live, hydrangeas will thrive in gardens with as little as three hours of direct sunlight per day. They prefer dappled light, so if your garden gets continuous indirect light all day—this might be sufficient for them as well. Hydrangeas also prefer morning light, which is typically gentler and less hot than afternoon light. While some hydrangeas will tolerate full sun (six hours or more of direct light), they’ll likley perform better with a bit of shade.
The exact preferences of your hydrangea will depend on which variety it is. While Oakleaf, Climbing, and Mophead Hydrangeas will all take between three to six hours of direct sun, other varieties (like Mountain, Panicle, and Smooth Hydrangeas) prefer more than that.
For the best results, plant your hydrangea in a partly-shaded garden bed where it’s protected from the wind and from getting too much sun. Be sure to monitor your hydrangea for signs of too much sun (or underwatering)—which generally manifests as burnt leaves and a lack of healthy-looking blooms.
Because of their size, hydrangeas are a popular choice for the edge of gardens underneath trees, or as background or border plants. Hydrangeas are also relatively easy to propagate if you’re looking to expand your collection. Keep in mind that most hydrangeas can grow as tall as they do wide, so it’s best to place them towards the back of the garden rather than in the front where they’ll likely obstruct the view of your other plants.
Growing hydrangeas in less than ideal light conditions
When it comes to hydrangeas, it’s possible to give them too little or too much light. For many hydrangeas, at least some shade is preferred. If you have an overly sunny garden then you might consider planting one of the varieties that do best in full sun, which include Mountain, Panicle and Smooth Hydrangeas. For shadier gardens with less direct light, Oakleaf, Climbing or Mophead Hydrangeas would be better.
Despite these guidelines, the light requirements for all hydrangeas will vary based on the conditions of your garden. While hydrangeas in moist, humid gardens may tolerate more sun than usual, those in drier ones may not. The best way to deduce if your hydrangea is getting what it needs is by simple observation. If the plants seem happy, and the leaves don’t appear burned or with stunted growth, then chances are your hydrangea is getting the amount of light it needs to thrive.
Hydrangea Light Requirements FAQs
Do hydrangeas like sun or shade?
Hydrangeas prefer a partly-shaded garden, ideally with four hours of direct morning light and several hours of dappled light or shade thereafter.
Can hydrangeas get too much sun?
Yes! Being a shade-loving plant, hydrangeas can absolutely get too much light. Watch for signs of burnt leaves and drooping flower buds to determine if your hydrangea is getting too much sun.
Do hydrangeas prefer morning or afternoon sun?
Hydrangeas prefer morning sun, which is generally cooler and less intense.
Can hydrangeas grow well in shade?
Hydrangeas grow best in part-shade, meaning they get some direct sunlight followed by a period of shade every day.
Do hydrangeas need light to germinate?
Hydrangea seeds do need light to germinate.
Ensuring your hydrangea gets the light it needs all starts with choosing a good spot in your garden. Spend some time observing how much sun your garden gets and at what times of day. Pick a spot for your hydrangea where it will be protected from the wind and can still enjoy some sun each day with plenty of shade during the warmer parts of the day. By planting your hydrangea in a place where it can thrive (rather than just a spot where you’d like it to be), you’ll be that much closer to having a healthier, less demanding garden.