Althea Plant: How to Grow and Care in Your Garden

This post contains affiliate links. If you click and buy we may make a commission, at no additional charge to you. Please see our disclosure policy for more details.

The Roses are red. The althea plant can be pink, purple, or blue. Isn’t that how the poem goes?

Also known as the “Rose of Sharon,” this rose copycat is one of the most attractive bushes you can grow in your garden.

And no doubt, it is also one of the easiest.

Does that mean you should plant it and hope it grows? Not that easy!

We want to show you EVERYTHING you need to do, so this plant thrives at home. From the moment you plant it to the moment, it’s already growing and becoming a full-blown shrub in your garden – you’ll know the whole path.

Are you ready to learn what we have to say? Check it all out below!

What is the Althea Plant Exactly?

What is the Althea Plant Exactly

The Althea plant (known as the Hibiscus Syriacus by its botanical name) is part of the Malvaceae or “Mallow” family. Even though you can find it as the “Rose of Sharon,” it is not exactly a rose but mallow (slightly different).

A typical Althea plant can grow to about 13 feet or 3 feet in shrub form. The foliage isn’t too dense but not too light either, so you get the best from both worlds.

It typically blooms in the summer up to early fall, sometimes taking an entirety of 6 months to bloom. And when that happens, the plant looks MAGNIFICENT. It can be blue, pink, purple, and sometimes even reddish – like a REAL rose!

Different Types of Althea Plant to Consider

There are various types of Althea to consider with different blooming times, colors, shapes, and sizes. What you will prefer will depend heavily on what looks better in your garden.

What would be that? The always-pink Aphrodite? The blue Azzurri? Or the gorgeous red Lucy? Learn more about each below:

#1. Aphrodite Althea (Hibiscus Syriacus “Aphrodite”)

Aphrodite Althea (Hibiscus syriacus “Aphrodite”)

This is one of the largest varieties. While not gigantic, it can reach 10 feet in height with no problem. The most beautiful part is the typical rosy hue, a beautiful tone that adds up to any garden.

These reddish flowers are pristinely gorgeous. Each blossom is large enough to cover up to 4 inches in diameter, so it can get awesomely colorful.

What makes it an excellent option is the shrubby-style foliage growth. You can make it work as a bush or hedge either way.

#2. Azurri Blue Satin (Hibiscus Syriacus ‘DVPazurri’)

Azurri-Blue-Satin-Hibiscus-syriacus-‘DVPazurri

This variety is large enough to reach 12 feet in size and cover up to 6 feet in width. For that reason, it is mainly considered a variety for large areas. You can still grow it in other places, as you can keep it small with good pruning.

But there’s nothing more attractive about it than the blueish flowers. These blossoms are uniquely stunning, making them a top-notch variety to have.

Once people see the vibrant blue in your garden, they won’t resist commenting about it.

#3. Diana Althea (Hibiscus Syriacus “Diana”)

Diana Althea (Hibiscus syriacus “Diana”)

The Diana Rose of Sharon is PERFECT for anyone who appreciates white flowers. And not only that, the plant itself is rich and gorgeous, adding up to an already eye-catching view.

As for the flowers, you can appreciate the pure-white tone, with a waxy texture and a ruffled shape. They can grow to 4 inches in diameter, so they can be easily seen from afar.

And lastly, it grows like a shrub that makes it excellent as a hedge or bush. It will bloom almost in any environment regardless.

#4. Lucy Althea (Hibiscus Syriacus “Lucy”)

Lucy Althea (Hibiscus syriacus “Lucy)

Do you prefer red roses? Then you’ll love Lucy Althea. Even though it typically grows reddish with slight pink tones, this flower doesn’t disappoint in the slightest.

It is a fast-growing and tall plant, reaching 10 feet in height in most cases. You can also enjoy the low-maintenance experience. It doesn’t need as much care as other Hibiscus syriacus varieties.

This is due mainly to the narrow growth. It doesn’t produce as many branches or grows as much foliage as other types. You get fast growth and little care at once.

#5. Purple Pillar (Hibiscus Syriacus ‘Gandini Santiago’)

Purple Pillar (Hibiscus syriacus ‘Gandini Santiago’)

Probably the largest of all Althea varieties. The Purple Pillar can reach a whopping 16 feet of height in most cases. And for spread, it can get 5 feet with no problem.

You will appreciate the hedge-like growth, though. It is easy to keep it thin and light without letting it take more space than it should.

The flowers are incredible, for one. The purple tone adds to an intense sight, with an exciting spot in the center typically darker than the other petals.

What Does an Althea Plant Need to Grow?

You can make your Althea either grow beautifully within a few months or get a just decent plant instead. What are you going for?

If you’d like to make it the BEST ALTHEA out there, you’ll take these factors into account:

#1. Space and Potting

Even though Altheas are not necessarily picky when it comes to space, they need a lot of it to thrive. It grows mainly as a shrub, so it won’t take as much space as big trees would.

Typically, enough space for an althea would be 3 to 6 feet, depending on the variety. Some of them, like the Lucy, will thrive with even less than 3 feet in space, while the Purple Pillar may demand up to 10 feet if you don’t prune it well.

You can grow this plant on pots at first, but it will likely demand repotting within the first year. We don’t recommend leaving it in pots less than 12 inches in diameter when the year arrives.

#2. Soil and Fertilizer

Althea isn’t a picky plant in terms of soil, either. But it’s still highly advised to use the right one if you want to avoid stunted growth over time. Or in other words, it’s better to give the plant the BEST SOIL POSSIBLE if you want to get the best Althea possible.

Here, nothing matches soil pH levels between 5.5 and 7.5. It obviously prefers rich soils and demands a well-draining texture, like sandy or crumbly ground.

Apart from that, you will need organic matter or consistent fertilization for it to thrive. Luckily, it is not a starving plant at all, so you can let it grow with fertilization every 3 to 6 months without problems.

#3. Water and Humidity

Once it grows into an adult, the Althea can handle several days without water. But as it grows, you will need to water it once a day without fault.

The recommended rate is about 1 inch per week. This should keep it well-watered and healthy as it grows and becomes an adult.

Keeping the plant watered daily in dry spells, long droughts, or scorching environments is essential.
With this in mind, consider that most Althea plants don’t like soggy soils. Don’t overwater unless you want issues later on.

#4. Sunlight and Aeration

Like most shrubs, you can grow it under the full sun without any problems. It can withstand up to 8 hours of daily sun exposure without struggling. And likewise, it doesn’t care if there’s too much shade either. The plant will thrive as long as it receives at least 4 hours of sunlight.

While it doesn’t demand much aeration per se, it’s better to keep it in a well-ventilated area.

#5. Temperature and Environment

The shrub is one of the most surprising when it comes to withstanding harsh environments. A typical Rose of Sharon can live in hardiness zone 5 (as little as -20 degrees Fahrenheit). But this is only the case for the smallest varieties. If you want a large Althea, you’ll want to keep it in hardiness zone 7 to 9.

As for the environment, they prefer the outdoors over the indoors. You can still grow them inside your home as long as they receive sufficient sunlight (4 hours a day) and are not starving of aeration either.

How to Grow an Althea Plant in a Few Easy Steps?

How to Grow an Althea Plant in a Few Easy Steps

It is likely not the easiest to grow, but it’s nothing out of the extraordinary either. This plant will thrive as long as you follow a few straightforward steps:

  1. Choose the Right Variety

    You should now be well aware of the different types of Althea plants available. It’s then time to pick the one that BEST matches your garden and needs.

    We recommend considering the amount of space available, what region you’re in, and the color you prefer to add to your garden.

  2. Pick the Perfect Place

    Are you done with the ideal type of Althea? Now make sure you’re planting it in the right place.

    This should be an IDEAL place. That is enough sunlight, a well-draining soil, and an excellent pH level. More importantly, it should be a clean area with little to no weeds, preferably with no grass either, so Althea doesn’t have to fight for nutrients.

  3. Fix the Place

    It mustn’t have any debris or unwanted vegetation. Clean it all up if necessary.

    For the best experience, fix the soil after weeding and cleaning. We recommend digging about 3 inches on the place you’re planting the Althea. Then mix the excavated soil with fertilizer and compost. This should make it perfect for the Rose of Sharon to thrive.

  4. Plant the Althea

    Most likely, you’re getting an Althea as a seedling or tiny plant. In either case, you’ll have to take it out from the original pot into the new place. For that, loosen up the bottom first and then slowly and gently get the plant out. Make sure you clean up the roots slightly and then plant the Althea in the new place.

  5. Pack the Bottom Soil

    With the plant already secured in the new place, it’s time to make sure it stays there for long.

    For that, you should pack down the soil around gently. The dirt should cover the root and a small portion of the stem.

    This will remove air pockets and prevent any unwanted soil behavior from now on. It’s worth knowing that putting way too much dirt on top of the root may cause damage. So stick to only patting down the area, so it gets compacted, and that’s it.

  6. Make the Last Amendments

    You can now add the last few amendments to finish the job. This is mostly about watering deeply until the entire root gets soggy. Then you can add some mulch or wood chippings on top. This should conserve the moisture and add extra nutrients to the soil.

  7. Let it Grow

    here’s not much else to do for now. You should just let the plant grow.

    We recommend leaving it to grow for at least 6 more months until it reaches nearly full maturity. In the meantime, only taking basic care of the plant will suffice.

How to Take Care of Althea Plant?

How to Take Care of Althea Plant

While the Althea will grow almost by itself once it’s properly planted (and given it is the right place), you shouldn’t do that much to help it thrive.

Having said that, here are some tips to consider:

Prune Consistently

This is NOT NECESSARY, but it helps enormously. For example, the largest varieties may not fit perfectly in your garden. Pruning every two months will be ideal if you want to keep it shorter.

Apart from that, you should ONLY PRUNE after flowering. That is, in winter or fall when the leaves are not there. This will give new space for the upcoming foliage and flowers to become vibrant.

Another excellent time to prune is when the leaves or branches look dead or damaged. Removing bad portions is always a wonderful thing to do.

Add Much

Adding mulch around the bottom section of the plant helps enormously. It increases the amount of moisture in the soil, protects against harsh winter freezing temperatures, and boosts nutrients so your plant can keep growing with a natural fertilizer.

Protect Against Pests

Because the foliage tends to be dense and the flowers boast an intense aroma, the Althea plant is typically a target for many pests. These include Japanese beetles who like to chew on the flowers, the spider mites and aphids who eat away most of the foliage, and whiteflies who leave their larvae behind.

You can prevent all of these by checking on your Rose of Sharon consistently. Make sure to remove any sign of pests (like eggs or larvae) as soon as they appear. This will keep your Althea growing uninterruptedly and without problems going forward.

Frequently Asked Questions (FAQs)

Q1. Can you use the Rose of Sharon as a hedge?

Ans. Yes, totally. As long as you prune it and keep it hedge-like, it will work like one. Of course, stick to the varieties with the densest foliage like the Purple Pillar or Aphrodite.

Q2. What kills Althea bushes?

Ans. Most Althea plants die when they’re exposed to excess humidity. A Rose of Sharon will develop root rot and eventually fungal diseases that kill it slowly, starting from the bottom and taking over the foliage over time.

Q3. How does an Althea look like in winter?

Ans. It loses all the foliage and flowers, and only the stem and branches will remain. That’s why it is the best time to prune, as it allows new wood to grow and the foliage to grow from it. This typically ensures a more vibrant Althea over time.

Q4. Is Rose of Sharon flowers edible?

Ans. Every part of the Althea is edible. From the blossoms to the bark and even the leaves – you can eat everything without fear. What makes it such an excellent thing to eat is the high vitamin C and antioxidant content.

Grow Your Own Althea Plant Today!

Overall, growing and taking care of an Althea plant is not as complicated of a job as people think. As long as you follow our advice above – it will become a piece of cake!

But don’t rush and take it slowly. The Rose of Sharon won’t grow over a short period either. So be patient, take every piece of advice above into consideration, and you’ll be ready to enjoy that Althea in no time.

What are you waiting to grow that Althea at home, then?

Leave a Comment