Hydrangeas are quite large plants, and it is not always possible to properly place them in the garden. So that in the future you do not need to transplant plants, you better know how much space hydrangeas need.
You have to plant Bigleaf hydrangeas and Panicle hydrangeas 6-12 feet apart. In the case of Oakleaf hydrangeas, they need to be planted 6-8 feet apart.
In general, hydrangeas should be planted apart at a distance equal to the width of one adult plant (for plants of the same size). You also need to add one extra foot to this value so that there is a small gap between the plants. For hydrangeas of different sizes, the planting distance should be equal to the diameter of the wider variety.
Next, we will consider in more detail how much space is needed for the most popular species and varieties of hydrangeas.
| Name | Width of a mature plant | Distance between plants |
| Bigleaf hydrangeas | 6-10 feet (1.8-3 m) | 7-11 feet (2.1-3.3 m) |
| Mountain hydrangeas | 2-4 feet (0.6-1.2 m) | 3-5 feet (0.9-1.5 m) |
| Panicle hydrangeas | 6-12 feet (1.8-3.6 m) | 7-13 feet (2.1-3.9 m) |
| Smooth hydrangeas | 3-5 feet (0.9-1.5 m) | 4-6 feet (1.2-1.8 m) |
| Oakleaf hydrangeas | 6-8 feet (1.8-2.4 m) | 7-9 feet (2.1-2.7 m) |
| Climbing hydrangeas | 5-6 feet (1.5-1.8 m) | 6-7 feet (1.8-2.1 m) |
An extra foot between hydrangeas is needed to avoid stagnant air and too much moisture. Otherwise, the hydrangea can become diseased and its leaves turn yellow. Also, be sure to check out the post on growing healthy hydrangeas.
Bigleaf (Mophead) hydrangeas
Bigleaf hydrangea is also known as Hydrangea macrophylla. It is medium in size compared to other species. Its width can reach 10 feet in maturity.
However, some varieties may be smaller. The size of most varieties ranges from 6 to 10 feet. The distance at which these hydrangeas should grow from each other is 7-11 feet.
Among Bigleaf hydrangeas, there are exceptions, namely Endless Summer Hydrangea. Its spread is 3-5 Feet, which is less than most members of the species. The distance between these plants will be 4-6 feet.
One of the smallest representatives of these hydrangeas is Edgy Hearts Hydrangea (spread 2 – 4 feet). Based on this, the planting distance will be 3-5 feet.
Read also: 5 Best Hydroponic Systems
Mountain hydrangeas
Hydrangea Serrata is a reasonably common species that can reach 2-4 feet in width. Accordingly, the cut on which to plant these plants will be 3-5 feet.
These are some of the most compact hydrangeas, so they are trendy.
Panicle hydrangeas
Hydrangea paniculata is the largest species, so it needs a lot of space. These plants can reach 6-12 feet in width. The distance at which you need to plant them is 7-13 feet.
Panicle hydrangea has varieties that differ significantly in size from others.
Limelight hydrangea spread 96 inches in mature age, so plant them at least 105 inches apart.
Little Quick Fire and Strawberry Sundae some of the smallest varieties, their width varies between 3-5 feet. The distance between these plants should be 4-6 feet.
Smooth hydrangeas
Smooth hydrangeas spread up to 3-5 feet so that the plants have enough space, plant them at a distance of 4-6 feet from each other.
For Annabelle hydrangea, you need to allocate a little more space, namely 7 Feet.
One of the most compact varieties among Smooth hydrangeas is the Invincibelle Wee White (spread 30 inches). Therefore, plant plants of this variety at a distance of 40 inches.
Oakleaf hydrangeas
This hydrangea extends to a width of 6-8 feet. For normal cultivation, you need to allocate at least 9 feet of space.
Climbing hydrangeas
Climbing hydrangea grows mostly upwards, so do not need a large area. The distance to other plants should be 7 feet. Even if the plant is close, it will grow upwards. Also, don’t forget to create a frame for these plants.
What if you plant hydrangeas too close together?
If the hydrangeas are planted too close to each other, then problems can arise over time.
First of all, the movement of air between the bushes will deteriorate. As a result, fungal diseases will be easier to develop on the leaves and stems.
The second negative consequence will be a lack of moisture. Hydrangeas love moist soil because they have broad leaves, and they evaporate a lot of water.
With compact placement, the plants will compete for moisture and may even wither in hot weather.
Also, hydrangeas will not have enough nutrients in such conditions, and as a result, the number of flowers will be less.
To free up space between plants, you need to prune them every year. In early spring, remove the side branches. This will reduce the diameter of the bush.
Prune the branches at ground level so that they do not grow back. Also, do not remove more than a third of the limbs; otherwise, the plant may get stressed.
You will also need to water the hydrangeas more often. Check the soil moisture near the plants to a depth of at least two inches.
With dense placement, hydrangeas will receive water from the depths, and the surface may appear moist, but deeper, the soil may be dry.
Water the hydrangeas as often as needed, but try not to form a swamp.
Feed the hydrangeas to get a lush bloom. The best result can be obtained using slow-release fertilizers with high phosphorus content.
By following all these rules, you can grow hydrangeas in a small area for a long time, but if you continue to have problems with this, then you should transplant your plants.
You can learn about when and how to transplant hydrangeas from the article Transplanting Hydrangeas: A Homeowner’s Guide. There I described everything in detail, and you will find some tips on how to avoid mistakes.
How far to plant hydrangeas from house or fence?
Very often, gardeners want to know at what distance you need to plant plants from the building or fence so that later there are no problems.
Plant hydrangeas at a distance of half its width (the width of an adult plant) from the house. For example, if your hydrangea reaches 5 feet wide in maturity, then you need to plant it at least 2.5 feet from the house or fence.
You can also step back an extra foot so that there is a gap between the house and the mature hydrangea. This will avoid shading the wall, and there will be less moisture near the home.
Also, remember that hydrangeas are best planted on the east side of the house because most species like the morning sun, and the rest of the day they prefer to be in the shade.
Planting on the west side is also possible, but there will be most comfortable only for Hydrangea paniculata.
Do not plant hydrangeas on the north or south side of the house. In the first case, the plants will have little light, and they may not bloom. In the second case, the excess sun will quickly dry out the soil, and the hydrangea will wither and burn.
All this applies to the planting of hydrangeas near the fence.
How far apart to plant hydrangeas for hedge?
For a hedge, hydrangeas should be planted at a distance of their width at maturity.
If, in previous cases, I recommend stepping back an extra foot so that there was a gap between the plants. In this case, you do not need to do this.
Hydrangea hedge spacing
| Name | Hedge spacing (center to center) |
| Bobo hydrangea | 3 ft (0.9 m) |
| Limelight hydrangea | 6 ft (1.8 m) |
| Annabelle hydrangea | 5 ft (1.5 m) |
| Pee Gee hydrangea | 15 ft (4.5 m) |
| Oakleaf hydrangea | 5 ft (1.5 m) |
| Little lime hydrangea | 4 ft (1.2 m) |
| Quick Fire hydrangea | 6 ft (1.8 m) |
| Firelight hydrangea | 5 ft (1.5 m) |
| Hydrangea paniculata | 8 ft (2.4 m) |
| Incrediball hydrangea | 4 ft (1.2 m) |
| Endless Summer hydrangea | 4 ft (1.2 m) |
To quickly get a beautiful hedge, you need to prune the plants each year slightly. Also, water them on time and with plenty of water.
For best results, fertilize the hedge and treat it with remedies.