Google’s most asked questions about Hydrangeas

Hydrangeas are native to Asia and America, most species being found in Asian countries including China, Japan, and Korea.

They have been cultivated in Japan for centuries, as early as 790 AD!

If it were a tree, it would need a single woody stem which branches out to form a crown.

Shrubs form branches from ground level, forming a crown without a stem.

This means that Hydrangeas can be classified as shrubs, rather than trees.

There are a great range of choices, with over 70 species, and over 600 individual named cultivars within the different types.

Here are some details about each variety to help you to identify them:

They come in a lovely range of colours, including blues, whites, pinks, and even green flowers. And some even come in a slightly purple shade.

The best time, after buying them in containers from garden centres, is in the autumn or spring. These times are best because it is still a little warm, not searing hot in the summer heat. And it is not too cold from the winter months.

They prefer moist soil but well-drained, so they aren’t sitting in too much of it but water is still easily accessible. Hydrangeas are fond of dappled shade, but not too much direct sun. This would mean that the plant would dry out too much.

Hydrangeas can tolerate most soil types, and pH. If you have quite sandy soil, it is best to dig in some organic matter to help the plant to retain some moisture.

Finally, when planting your Hydrangea, use the container it came in as a guide. Never plant it deeper than the container it previously lived in.

Panicle varieties do particularly well in direct sunlight rather than other varieties.

If you’re not sure which type to choose, your local garden centre will be able to offer you some advice.

Generally though, Hydrangeas do prefer partial or dappled shade.

They tend to grow between 3 and 8 feet tall, and approximately 4 to 6 feet wide.

Climbing Hydrangeas tend to grow taller, as they attach to your wall via roots, similarly to ivy.

Dwarf varieties of Hydrangea are generally better for pots, as they are less likely to outgrow the container. These pots can be placed on patios, balconies, or other outdoor areas, just try to find somewhere with dappled shade

Make sure to water them well, as the plant relies on the gardener to give them constant access to a water supply. Once your Hydrangea is fully grown, it will still need to be moved into a larger container, or straight into the ground

When choosing where to take your cutting from, aim for a non-flowering shoot about 10-15 cm long.

Trim below a node, which are swellings on the stems. Remove the lower leaves as you go to save your cutting energy.

Any leaves remaining on the stem should be cut in half widthways, which helps to reduce water loss.

Pop your cutting into small pots that are filled with gritty, peat-free compost. Firm them in well, and soak with water straight away, and it will soon establish roots and start to grow.

You can grow Hydrangeas from seed! Wait until spring comes around to start sowing, the earlier in the season, the better.

Sow them on the surface of peat-free compost in a tray, and keep the soil moist. Make sure the seeds are protected from any cold winds and drafts. One of the best places is a greenhouse if you have one, or a windowsill or in the porch inside your home.

You should see them beginning to germinate within 14 days of sowing!

Because Hydrangeas are quite woody plants, they will struggle to propagate in water. Give it a go, it’s always worth a shot and the results may well be worth it.

I would recommend for a higher chance of success, to plant your cuttings in soil instead.

The best time to take cuttings from your Hydrangea is in late summer. These cuttings will be semi-ripe, so will have some maturity in this new growth.

They will be from the current season’s growth, but old enough to have a woody base, which prevents rotting.

Moist, but well-draining.

They thrive in most soil conditions, but adding organic matter always helps. This supports any microorganisms in the soil that produce food for your Hydrangea plant.

The flowers of certain varieties of Hydrangea can change colour, determined by the conditions they live in.

This is dependent on the pH level of the soil.

Understanding what type of soil you have is key, and you can test your soil easily with kits you can buy at the garden centre.

It is typically Hydrangea serrata and Hydrangea macrophylla that change colour dependent on the soil pH.

The flowers go blue more acidic soils, and pinker in limey/alkaline soils.

You can purchase packs that will help to alter the pH of your soil for your preferred flower colour.

This could be the natural process of the changing seasons, as the leaves are deciduous and shed in the autumn.

If they are turning yellow during the spring and summer, it could be caused by an iron deficiency. This is called chlorosis, where the plant can’t produce enough chlorophyll.

By adding ericaceous plant food, you can boost your Hydrangea’s iron levels.

This yellowing could also be down to overwatering, which waterlogs the roots.

The most likely cause of this is underwatering, which leads to the leaves drying out.

I suggest checking that your plant doesn’t have too much sunlight, and has enough moisture in the soil.

This could be caused by your plant getting too much or not enough sunlight.

Also, it could be caused by improper pruning, as different varieties flower on different parts of the wood. It is best to check which variety you have, so you don’t prune the wrong parts of the plant.

You may be using the wrong fertiliser on your Hydrangea, as a great deal of nitrogen encourages foliage growth, and little to no blooms.

Underwatering may also cause this, as the plant won’t have adequate energy to produce flowers.

Again, Hydrangeas aren’t particularly fussy about the pH level of their soil, and this mainly serves to alter the colour of the blooms.

If you would prefer blooms pinker, depending on the variety you have, lime is a great addition to your soil. It will boost the colour.

Yes, they do! They flower once a year, reblooming doesn’t really happen on standard varieties.

After the flowers have died, the bronze, dried florets can still make quite a nice display. It also offers some slight protection for the plant during the winter.

Hostas are quite good – they have similar growing conditions such as watering requirements, and preference for dappled shade. Their drop-shaped leaves do wonders to highlight the greenery and pastels that Hydrangeas are known for.

Echinacea purpurea are another fantastic option, as they flower at the same time as Hydrangeas. They also grow well in similar conditions.

Ornamental grasses are a wonderful backdrop, offering a great textural contrast.