Clethra Alnifolia (Ruby Spice Summersweet): Plant Care and Growing Guide
There’s something incredibly rewarding about watching a plant thrive under your care—especially one as charming and fragrant as the Ruby Spice Summersweet. When I first came across Clethra alnifolia ‘Ruby Spice’, I was drawn in by its vibrant pink blossoms and the subtle, spicy scent that lingered on warm summer evenings. Unlike fussier plants, this one quickly earned its place in my garden for being both beautiful and surprisingly easy to manage.
But even the most low-maintenance plants need a little love. How do you make sure your Ruby Spice Summersweet blooms to its full potential year after year? Whether you’re planting it in a shady corner or tucking it into a pollinator garden, a few key care tips can make all the difference.
That’s where this guide comes in. We’ll walk through everything from ideal growing conditions to pruning tips—so you can grow a lush, healthy shrub that rewards you season after season.
The basic care guidelines you need to remember for your Ruby Spice Summersweet are the following:
- Water: The Ruby Spice Summersweet loves moist soil but will still survive dusty soil when it is established.
- Light: Keep your Clethra Alnifolia ‘Ruby Spice’ in an environment where it can receive partial sun on a daily basis.
- Soil: Make sure to keep the Ruby Spice Summersweet in soil with moist but well-draining to poorly draining properties, so ideally, one that is made of sand, loam, and clay.
To keep your Ruby Spice Summersweet healthy, just remember these three care factors.
Scientific / Botanical Aspects
The Ruby Spice Summersweet belongs to the Araceae family. Its genus is Colocasia, and the species is Esculenta. This gives it the scientific name Clethra Alnifolia ‘Ruby Spice’ (KLEE-thra al-nee-FOH-lee-uh).
Like other Colocasia plants, the Ruby Spice Summersweet is deciduous. This means it loses its leaves every autumn.
Growing Region
The Ruby Spice Summersweet is a plant native to the India to Southern China and Sumatera.
Remember your plants’ native region and environment. This helps your Ruby Spice Summersweet thrive in the conditions it knows best.
The Clethra Alnifolia ‘Ruby Spice’ thrives in heat zones 8 to 12. Its hardiness ranges from 8b to 11a. The ideal climate falls between zones 12 and 24, including H1 and H2.
Growth and Size
Growth
The Ruby Spice Summersweet grows slowly. This is great for plant lovers.
Size
But, how big does the Ruby Spice Summersweet actually get? What should you expect in terms of size? Let’s dive right in…
The Clethra Alnifolia ‘Ruby Spice’ can grow up to 3′ – 4′ (90cm – 120cm) in 3′ – 4′ (90cm – 120cm) and 2′ – 3′ (60cm – 90cm) in 2′ – 3′ (60cm – 90cm).
The Ruby Spice Summersweet is a medium-sized bulb. Keep this in mind when deciding where to place it in your home.
Experts suggest keeping about 36″ (90cm) clear. This space helps the Ruby Spice Summersweet grow well.
Water
In terms of watering, the Ruby Spice Summersweet is a fairly complicated plant to take care of.
This is mainly due to its tricky watering schedule and regular watering needs.
Specifically, most experts agree that the Clethra Alnifolia ‘Ruby Spice’ loves moist soil but will still survive dusty soil when it is established.
Which is why it is considered a plant with relatively average needs in terms of water.
Watering
Keep your Ruby Spice Summersweet in soil that is moist but drains well. This will help your plant grow and thrive.
Choose soil with good drainage. It should be moist and sometimes wet. This will help maintain the right moisture levels at all times.
In our experience, the best way to know how much water your Ruby Spice Summersweet needs is the ‘thumb’ technique. To check if your plant needs water, stick your finger into the soil. If it feels moist, skip the watering. If it’s dry, then it’s time to water your leafy friend. This is the best way to care for your plant.
Soil Mix
When it comes to growing a healthy Ruby Spice Summersweet, soil really matters. This charming shrub prefers soil that’s both well-draining and able to retain enough moisture to keep its roots happy. Striking that balance means mixing sand, loam, and a bit of clay for the ideal growing environment.
Most experienced gardeners recommend soil that leans heavily on loam and clay (also called silt). This combination offers enough structure to hold moisture while still allowing excess water to drain away, preventing soggy roots.
Here’s a quick breakdown of what the plant prefers:
| Soil Component | Purpose | Benefit to Plant |
| Sand | Improves drainage | Prevents root rot |
| Loam (Silt) | Provides nutrients and moisture | Boosts growth |
| Clay | Holds moisture and minerals | Supports healthy root systems |
Finally, aim for a soil pH that’s neutral to slightly acidic for best results. This will help your Ruby Spice Summersweet truly thrive.
Light and Exposure
In terms of light & exposure, the Ruby Spice Summersweet requires partial sun in order for it to thrive under the right conditions.
Most experts agree that this bulb will do well as long as you keep it in partial to full sun, and it will be able to grow properly.
We recommend placing your Clethra Alnifolia ‘Ruby Spice’ in partial shade, with 2 to 6 hours of direct sunlight each day. It can also thrive in full sun, which means more than 6 hours of direct sunlight daily.
Season
Being a deciduous plant, the Ruby Spice Summersweet will shed its leaves annually once autumn comes.
But, you can expect it to have its ‘prime-time’ during the spring (early, mid, late), the summer (early, mid, late), the fall, and during the winter.
Flowers
This bulb is famous for its fragrant, showy flowers among plant lovers.
The Ruby Spice Summersweet produces some beautiful pink, or green, gold/yellow and white flowers around this time of year.
Foliage
The leaves from the Ruby Spice Summersweet have a beautiful green color during most of the year.
In particular, they have a simple arrangement with a rosulate organization in its leaves.
You can expect the leaves from your Clethra Alnifolia ‘Ruby Spice’ to be around (> 6 inches) in size.
Attracts, Tolerance and Resistance
The Ruby Spice Summersweet tolerates wet soil well. So, if you get some rain, your Clethra Alnifolia ‘Ruby Spice’ will be just fine.
Garden
How should you then organize your garden to include your new Ruby Spice Summersweet? Here are some recommendations by expert gardeners.
Most Clethra Alnifolia ‘Ruby Spice’ owners agree that this bulb will look great in most cottage gardens of all types.
Other owners consider that they complement well most gardens of mediterranean garden styles.
The Ruby Spice Summersweet thrives in several spots in your garden. You can plant it in ponds
Companion Plants
Pairing your Ruby Spice Summersweet with the right companions can elevate the beauty and health of your garden. This shrub does best when planted alongside other species that share similar light and soil preferences. Choosing the right plant neighbors can also help create a more balanced and low-maintenance landscape.
A popular companion is Buxus, commonly known as boxwood. Its dense, evergreen foliage contrasts beautifully with the airy blooms of the Summersweet, adding structure and year-round greenery to your garden bed.
Another excellent option is Weigela. With its graceful arching stems and springtime blossoms, Weigela adds softness and a burst of color that complements the pink spikes of Ruby Spice.
Top Companion Picks:
- 🟢 Buxus (Boxwood) – adds structure and evergreen presence
- 🌸 Weigela – offers colorful blooms and gentle texture
Choose the plant that suits your space and style—both make excellent partners for a thriving garden scene.
Conclusion
So that’s it! Here are the key care tips for keeping your Ruby Spice Summersweet healthy at home or in your garden.
