The Complete Guide for St. John’s Wort (Hypericum Calycinum) Care

The St. John’s Wort, otherwise known as the Hypericum Calycinum or Aaron’s Beard, Rose of Sharon, Resurrection Plant, Large-Flowered St. John’s Wort, Creeping St. John’s Wort, is a rather well-known shrub plant by gardening enthusiasts around the world.

Best known for its low maintenance and moderate growth, this shrub will likely liven up your house (or garden) with its green-colored leaves. But, only if you learn how to take proper care of it for it to thrive.

Fortunately, taking care of your St. John’s Wort is not too difficult – as long as you follow our guidelines in this St. John’s Wort Care Guide. Now let’s get started.

In order to take proper care of your St. John’s Wort you’ll need to keep in mind the following guidelines:

  • Water: The St. John’s Wort requires minimal watering once established.
  • Light: Keep your Hypericum Calycinum in an environment where it can receive partial to full sun on a daily basis. 
  • Soil: Make sure to keep the St. John’s Wort in soil with well-draining properties, so ideally, one that is made of clay, loam, chalk, and sand.

And that’s practically it! If you keep these three factors in check, your St. John’s Wort will likely have all it needs for it to survive and even thrive.

Scientific / Botanical Aspects

In botanical terms, the St. John’s Wort belongs to the Hypericaceae family, the genus Hypericum and the species Calycinum, hence its scientific (or botanical) name Hypericum Calycinum.

As with other Hypericum’s, the St. John’s Wort is a deciduous plant, which means it will shed its leaves annually once autumn comes.

Growing Region

The Hypericum Calycinum is native to southwest Asia and southeast Europe.

Knowing your plant’s native region is very useful, as it can give you tips on which environment is best for your St. John’s Wort. If you keep it in mind, you can try to replicate these conditions at home, and you’ll likely end with a healthier plant.

With this in mind, the Hypericum Calycinum will be most used to the heat zones in the 4 – 9 region, as the plant hardiness level falls between 6a, 6b, 7b, 7a, 8a, 8b, 9a, 9b, 10b, 10a and the ideal climate zone is between 2, 2B, 3, 3A, 3B, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24.

Growth and Size


In terms of size and growth, the St. John’s Wort is a relatively moderate grower, which makes things somewhat easy for any plant enthusiast.


But, how big does the St. John’s Wort actually get? What should you expect in terms of size? Let’s dive right in…

The Hypericum Calycinum can grow up to 1′ – 2′ (30cm – 60cm) in 1′ – 2′ (30cm – 60cm) and 1′ – 2′ (30cm – 60cm) in 1′ – 2′ (30cm – 60cm). 

These dimensions make the St. John’s Wort a relatively medium shrub compared to others, so it’s best to keep this fact in mind since it will affect where you want to keep yours at home.

This is why experts recommend keeping an area of approximately 18″ (45cm) free so the St. John’s Wort can spread to its best extent.


In terms of watering, the St. John’s Wort is a fairly complicated plant to take care of. This is mostly because it has a not so straightforward watering schedule and somewhat irregular watering needs.

Specifically, most experts agree that the Hypericum Calycinum requires minimal watering once established.

This is why it is considered a plant with relatively average needs in terms of water. 

As a rule of thumb, you should remember to keep your St. John’s Wort in soil with well-draining characteristics, as these will guarantee the right conditions for your plant to grow and thrive. 

In our experience, the famous ‘thumb’ or ‘finger’ test is what works best for the St. John’s Wort since with it, you will be able to give it the right amount of water, every time – regardless of the environment or placement where you do decide to keep it.

Soil Mix

The St. John’s Wort’s ideal soil potting mix is made out of clay, loam, chalk, and sand.

This is why most experts agree that the St. John’s Wort requires soil with loam (silt), which will give you the right conditions it needs.

In addition to this, expert gardeners recommend having preferably alkaline, acid or neutral soil.

Light and Exposure

In terms of light & exposure, the St. John’s Wort requires partial to full sun in order for it to thrive under the right conditions. 

Most experts agree that this shrub will do well as long as you keep it in partial to full sun, and it will be able to grow properly.

Specifically, we recommend that you place your Hypericum Calycinum in little to partial shade (only 2-6 hours of direct sunlight a day), to full and direct sun (more 6 hours of direct sunlight per day).


Being a deciduous plant, the St. John’s Wort will shed its leaves annually once autumn comes. However, you can expect it to have its ‘prime-time’ during the summer (mid, late), and during the fall.


You can expect your St. John’s Wort to flower around the spring and in the summer months from April to June (spring), and from July to September (summer). In particular, this shrub is well known for its flowers for cutting and showy flowers around the plant enthusiast community.

The St. John’s Wort produces some beautiful yellow or gold flowers around this time of year.


The leaves from the St. John’s Wort have a beautiful green color during most of the year.

In particular, they have a simple arrangement with an opposite and whorled organization in its leaves.

You can expect the leaves from your Hypericum Calycinum to be around (3-6 inches) in size.

Attracts, Tolerance and Resistance

The St. John’s Wort is well known for its tolerance to dry soil and drought conditions, so don’t worry if any of these come along, your Hypericum Calycinum will be fine.


Now, let’s talk garden and how your St. John’s Wort will look best in it.

Most Hypericum Calycinum owners agree that this shrub will look great in most mediterranean, cottage and rustic gardens of all types. 

Other owners consider that they complement well most gardens of informal and cottage, gravel and rock garden, and in prairie and meadow styles. 

In particular, the St. John’s Wort’s best location within your garden is in beds and borders, banks and slopes, and in ground covers, others use it for landscaping in a cutting garden,


And we’ve come to an end. Fortunately, that’s everything you need to know about your St. John’s Wort to keep it safe and sound in your garden or home. Enjoy planting!

Martin Duran

Hey y'all! My name is Martin Duran and I am from Cali, Colombia. Since 2018 I have been learning about plants and how to take care of them. Here's is my journey... “The clearest way into the Universe is through a forest wilderness.” ― John Muir

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