There are a lot of factors to consider when planting hydrangeas: in beds or pots, information on soil requirements, and the best plants to accompany hydrangeas can be found here.
While the Hydrangea genus consists of a wide variety of species, the most notable and most common variety found in most gardens is the bigleaf hydrangea (Hydrangea macrophylla). Here is our guide on how to plant hydrangeas in the garden, regardless of which hydrangea variety you choose.
This section discusses the right location for hydrangeas and which soil to plant them in. Here we will also talk about the difference between growing hydrangeas in pots, garden beds, or as hedges and give you tips on replanting as well as companion plants to the hydrangea.
- Planting hydrangeas: the ideal location
- Planting hydrangeas
- Replanting hydrangeas
- Companion plants for hydrangeas
Planting hydrangeas: the ideal location
Most woody and shrubby hydrangeas originate from the temperate areas of East Asia, where they can be found in the undergrowth of native forests where they are exposed to very little light. Even though hydrangeas can be cultivated around the world nowadays, these flowering shrubs should still be planted in a shady spot, ideally a semi-shade location. When exposed to too much shade, hydrangeas will not grow well and develop long and thin-leaved shoots, with little flowers. Hydrangeas can get gradually used to a sunny location, but because they also require a large amount of water, they can dry out faster than expected.
Planting hydrangeas: soil requirements
Hydrangeas need to be planted in slightly acidic soil, a pH value between 4 and 5 is optimal, and should never exceed 6.2. Notably, the pH value of the soil will influence the hydrangea’s colour: the more acidic the soil (5.5-6.2) will colour the hydrangea in red or pink, while the more alkaline the soil (5.2-5.5) will colour hydrangeas blue. Slightly more alkaline soil does not have any drastic or life-threatening effects on the plant or its growth, but an alkaline pH value can in the long run lead to deficiency symptoms or the desired colour of the flowers not forming. For further information on yellow leaves on hydrangeas click here.
It is also important to pay attention to the hydrangea’s high water requirements. Drought damage can occur quickly in hydrangeas, and hydrangeas should be planted in soil with a good water-holding capacity. The soil should however at the same time not be prone to waterlogging, as this may quickly lead to deadly root rot.
Summary: Where to plant hydrangeas
- Soil with a pH value between 4 and 5.5
- Soil with a good water-holding capacity
- Avoid waterlogging when watering
- Semi-shade location
Hydrangeas can not only be cultivated in garden beds but also as potted plants. If you can’t get enough of the beautiful bushes, we will show you how to plant hydrangea borders.
Planting hydrangeas in garden beds
Once you find a suitable spot in the garden to plant your hydrangea, there is one more step to consider before proceeding. For soils with too high a pH value, it is a good idea to dig a slightly larger hole. Thus there is more space for some added soil with a suitable pH value, such as rhododendron soil. Loosen up the soil around the plants to enable the hydrangea to take root and make sure that the soil is not too compacted after planting! It is a common misconception that stepping on the ground surrounding the plant will help it ‘hold better’ in place. As always, water your plant well before and after planting.
Summary: Growing hydrangeas in garden beds
- If necessary, replace some soil in the garden bed with a soil with a suitable pH value (for example, rhododendron soil)
- Water the hydrangea well before planting
- The soil around the hydrangea should be loose and airy
- Do not plant hydrangeas too deep in the ground
- Press the soil down only lightly
- Water the hydrangea thoroughly so that the soil settles
Planting hydrangea flower beds
To plant hydrangea flower beds choose a sunny to a semi-shady location in the garden. Hydrangeas should be planted in spring or early summer, though they can also be planted in autumn. When planning your garden, keep in mind that the hydrangeas are large plants that will grow bigger. Make sure to keep enough planting distance, the planting holes should all be twice the size of the pots you bought the hydrangeas in. Use a hoe to loosen the soil at the bottom of the planting holes a bit to help the roots spread. To meet the soil requirements of hydrangeas, add a soil with low pH. Mixing garden soil and planting soil can also help stimulate root formation.
Before planting the hydrangeas, water the root ball well. To water the root ball, place the plant in a bucket of water until air bubbles stop rising. Just before planting, carefully loosen the root ball a bit to encourage their growth. Place the hydrangea in the planting hole and fill it with the mixture of garden soil and hydrangea soil.
Tip: Do not plant your hydrangea too deep, the top of the root ball should be level with the soil.
Planting hydrangeas in pots
Though hydrangeas are large plants, they can also be cultivated in pots. Hydrangeas prefer semi-shade locations and should still be located in one even when potted. As potted hydrangeas dry out easily, they require regular watering. The container should provide enough space for the hydrangea to grow.
Since hydrangeas prefer a slightly more acidic pH value in the root zone, it is recommended to use rhododendron or azalea soil when planting. For an optimal water supply from the beginning, the hydrangea can be dipped into a bucket filled with water just before planting. The plant is kept completely submerged until no more air bubbles rise. After planting, you should water the hydrangea thoroughly again so that the loosened soil settles and the roots have access to water and nutrients.
Summary: Potted hydrangeas
- Semi-shady location
- Choose a large enough flower pot
- Water the hydrangea well before planting
- Use rhododendron or azalea soil
- Water well after planting
Growing hydrangea borders
Hydrangeas have traditionally been grown as hedges. Unfortunately, the beloved bigleaf hydrangea (Hydrangea macrophylla) is one of the few hydrangea varieties that can not be grown as a hedge because of their shape and sensitivity. Other hydrangea varieties make wonderful borders though, the panicled hydrangea (Hydrangea paniculata), for example, is well suited for this purpose. You can prune it to whatever shape you need it to be. The colour range of hydrangea borders is somewhat limited, only white or light pink hydrangea species can be grown as hedges. When planted at a distance of one metre, a dense hedge will quickly develop. Hydrangea hedges should be watered regularly and pruned in autumn or spring.
Summary: Planting hydrangea borders
- The best variety to grow as a border is the panicled hydrangea
- Plant the hydrangea at a distance of 1 m
- Water regularly
- Prune annually (in autumn or spring) to maintain shape (cut back up to half the shoot length)
Repotting can be a stressful experience for plants, hydrangeas included. They should be repotted as seldom as possible, though if replanting cannot be avoided, there are a few tips and tricks to help the hydrangea adapt to its new location with ease.
When to replant hydrangeas
Hydrangeas are best repotted in autumn. In the fall, plants conserve energy because they no longer have to grow new shoots. This lets the hydrangeas concentrate on developing new and healthy roots. Of course, hydrangeas can also be replanted in spring or summer, but the risk of damage caused by drought is much higher.
How to replant hydrangeas
Here is our step-by-step guide on how to move hydrangeas safely:
- Repot hydrangeas ideally in autumn
- Prepare the new planting hole
- Dig up the root ball and leave enough space around it so as not to harm the roots
- The diameter of the entire plant should be around the size of the root ball
- Carefully dig the plant up
- Make sure that the root ball remains as intact as possible
- Plant the hydrangea at the new site
- Water generoulsy after planting
Tip: Fertilising hydrangeas in pots is especially important because the nutrients are used up more quickly than in beds due to smaller soil volume. Natural slow-release fertilisers like our Plantura Hydrangea Food can help potted hydrangeas stay well-fed. If you are planting blue hydrangeas, you need a special fertiliser that helps them maintain their blue colour. You can learn more about maintaining blue hydrangeas here.
- For beautiful hydrangeas with lush blooms in pots & flower beds
- Prevents common deficiency symptoms & supports healthy plant growth
- Long-lasting fertiliser that is free from animal products - child & pet friendly
Companion plants for hydrangeas
Hydrangeas are stunning stand-alone plants, but you can also combine them with other plants. Here are some suitable companion plants that will compliment your hydrangeas.
Companion plants for hydrangeas in garden beds
Garden beds come alive with blooming plants and the same goes for shrub beds. It is a great idea to plant various perennials around the hydrangea. The following plants do particularly well in the hydrangea’s company:
- Vibrantly coloured autumnal or winter grasses
- Lady’s mantle (Alchemilla epipsila)
- Christmas rose or black hellebores (Helleborus niger and Helleborus x hybridus)
- Assorted ferns
Of course, many other plants make suitable companions for hydrangeas. The most important criterion is however always that they share the same (semi-shade) location preferences.
Planting companion plants underneath hydrangeas
Another option on how to fill out empty spaces in a hydrangea garden bed is to plant underneath the brush. More branchy hydrangea varieties leave a good amount of ground space left uncovered. Here are some plants that grow nicely beneath a hydrangea:
- Spring growing and flowering bulbous and tuberous plants such as daffodils, tulips or crocuses
- Let shade-compatible ground cover plants like ivy (Hedera helix) or bugleweed (Ajuga) thrive in the shade of the lavishly branched hydrangea