When does the rhododendron bloom and what do you need to do it?

Rhododendron blooms in spring

Rhododendron is a shrub that is characterized by being a bushy evergreen plant that produces relatively large flowers with brightly colored petals. These are so beautiful that when we see them in a garden or in a nursery, it can be hard for us to avoid looking at them; Also, if we dare to buy one, we probably want it to bloom every year.

Achieving it is not really difficult, but as we are going to explain, it is a plant that has somewhat particular needs. So We will tell you not only when the rhododendron blooms, but also what to do to make it bloom.


When does the rhododendron bloom?

Rhododendron is a perennial shrub

Image – Flickr/Bernt Rostad

The rhododendron is a shrub native to Southeast Asia, although there are some species that are from other places, such as the Pontic rhododendron, originating in Europe. It usually grows in places where the temperatures are mild, that is, neither too high nor too low, and almost always in areas where the sun only shines for a few hours.

In addition, for it to flower, it needs temperatures between 10 and 20ºC. In other words, it will only produce flowers when winter ends and spring begins to appear.

What is the rhododendron flower?

The flowers of our protagonist are quite large since they are about 2-3 centimeters wide. They appear grouped in clusters and their petals can be pink, lilac, white or red depending on the variety.

As it recovers well from pruning, one can even think of having several specimens in the same planter for example.

How long do rhododendron flowers last?

Rhododendron blooms in spring

Image – Wikimedia/Jean-Pol GRANDMONT

Flowers they stay on the plant for about 20 days or so (between 15 and 25 to be exact), as long as the conditions allow it, because if, for example, the temperatures exceed 30°C, or if, on the contrary, they drop below 0 degrees, then they will suffer damage and may fall.

That’s why if you live in an area prone to late frosts, protect your plant if it starts flowering before the risk of frost has passed. For this, it will be enough to put it under a roof, or if you prefer, to wrap it in an anti-freeze fabric like this.

What do you need to thrive?

Rhododendron is a plant that is said to be very easy to care for, but this is only half true. It’s easy if the climate and growing conditions are good, but otherwise… things change. So, while in Asturias or Cantabria he will be able to grow in luxury, in Almería or even in my region, the south of the island of Mallorca, he will have many problems.

For him, it is important that we know what the needs of our protagonist areso that we can do what we can to make it bloom well, without costing you:


We’ll start talking about it, because it’s the most important thing. The climate should be temperate, with temperatures neither too high nor too low. Ideally, summers should be mild (up to 30°C) and in winter, if there are frosts, they should be light or moderate (down to -15°C).

Likewise, ambient or air humidity must be high, greater than 50%, because it is a plant that cannot live in places where the environment is dry or very dry. If it rains frequently in your area, or if you are near a coast, a river or a swamp for example, you will not have to worry about it; but if, on the other hand, you are more indoors, and/or if you have any doubts, I recommend that you buy a home weather station with an outdoor sensor like this so that you know at all times what the percentage of humidity in the place where you have your rhododendron


Rhododendron is an acidic plant

Image – Flickr/UBC Botanical Garden

The soil must be acidic, or in other words, it should have a low pH, around 4-6. The rhododendron cannot grow in clay soils, because in these the iron, which is an essential nutrient for photosynthesis, is blocked there and therefore inaccessible. Therefore, if you are not sure whether the soil in your garden is suitable, find out about its pH, for example with a meter.

But if you already know that it is clay, then I advise you to plant your plant in a pot with a specific substrate for acid plants like this.


We want it to thrive, so one way to help it do that is to fertilize it from late winter through summer. For this you can apply a fertilizer such as guano (organic, not mixed with fertilizers, like this one) which contains many nutrients, such as nitrogen, phosphorus and potassium.

But yes, it is very important to apply it well, following the instructions on the package, because although it is natural, it is so concentrated that if we overdo it, the roots will burn.

With these tips, your rhododendron will thrive, that’s for sure.

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