The French hydrangea is one of the most common varieties of hydrangeas. This is also known as the bigleaf hydrangea and hydrangea macrophylla, and is one of the main 4 hydrangea varieties.
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2 of the most common types of French hydrangeas include the mophead hydrangea and the lacecap hydrangea. This is the most common hydrangea to see in a garden, because of it’s spectacular flower heads and colors.
Related: Mophead Hydrangea, Lacecap Hydrangea
The French hydrangea is a shrub that, with the right circumstances, will be covered in their flower heads from summer until autumn.
As this is a bigleaf hydrangea, it is distinguishable by the large leaves that grow to about 6 inches long. It is also one of the old wood hydrangeas, which means that the flowers bloom on stems that were there the previous winter, rather than fresh growth (keep reading for more information on pruning!)
Why’s It Called The French Hydrangea?
It would make sense if the French hydrangea was named after where it is native to, but it actually originates from Japan. Most hydrangeas are native to Japan and parts of Asia.
This hydrangea variety became very popular in France in the late 1700’s which is where this name comes from.
One reason why this variety of hydrangea is so wildly popular is because of the spectacular color options of this flower, and how you can actually change the color of the hydrangea based on the pH of the soil.
This works for both the mophead and the lacecap. The flowers act as almost a pH test strip, going from pink to blue and various depths of both depending on the pH.
Just remember that this does not work on the white varieties of this plant. If you have a white hydrangea in the French variety (or other varieties!), it will not change color.
Either test the pH of your soil and physically change it to which color you’d prefer, or be surprised by the color the flowers turn to!
If you’d prefer pink, try to get the soil neutral, around a pH of 6-7. If you’d prefer blue, have the soil acidic, preferably around a pH of 5.5-5.
Just keep in mind that if you are doing this in a garden, you may have varying success of changing the pH as there is so much soil around. (This may work better in potted miniature hydrangea varieties.)
Soil & Nutrient Needs
As mentioned above, the pH can change the color of the hydrangea, so if you are choosing to try to make it a specific color, first check the pH of your soil.
If you want to make it more acidic, try adding things like coffee grounds, peels from citrus fruits, or acidic compost, or purchase aluminum sulfate. If you want to make it neutral, give it plenty of phosphorous feedings, as well as chalk or limestone addition to the soil.
In general, hydrangeas prefer well draining soil, or else they can be prone to root rot. Add composted soil around the top of the plant if you have some to use.
Use a phosphorus based fertilizer to keep this hydrangea happy and healthy, and avoid nitrogen based fertilizers!
Hydrangeas prefer a decent amount of water without their roots being submerged in water. If it’s a dry spring, or you’ve just planted a new hydrangea, give it plenty of water.
It may also need a few extra waterings on those hot summer days.
This hydrangea variety needs about 6 hours of sun a day, but to also avoid the afternoon heat in the summer. Ideally grow this French hydrangea in a place where it can receive afternoon shade to keep it from wilting in the hot weather.
Not enough sunlight is another cause of hydrangeas not blooming, and may mean you have to transplant your hydrangea.
As the French hydrangea is one of the old wood hydrangea varieties, this one needs to be pruned in the autumn/beginning of winter. Simply deadhead the flowers that have died off and it should grow new flowers in the spring!
This is also a good time to prune off any dead branches or any that may be spreading out too far. Just keep in mind that the hydrangeas will only flower on the stems that were left there over winter.
This is probably the trickiest part of growing a French hydrangea, or old wood hydrangea, is that they don’t do well with over-pruning or taking it down a lot size wise. It can be a reason why your hydrangea isn’t blooming. (Read more reasons why your hydrangea isn’t blooming here).
Keep In Mind
These are beautiful flowers on shrubs that can grow up to 6 feet in height and 10 feet wide, so give it plenty of space to spread out!
These are a poisonous plant when ingested, and can cause some digestive problems when eaten by pets or humans. And despite this, they will be eaten by deer if there is not anything else around that they would prefer to eat.
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