Asperula Plant Growing & Care Guide for Gardeners

Article by Dean Ravenscroft, Ph.D. - Updated 15th Nov 2023

In this Gardener's HQ guide, we'll explore cultivating Asperula plants in your garden, indoor spaces, and other settings.

Woodruff, Sweet Woodruff: Cultivation & Garden Use

Plants from the Asperula genus can either be hardy annuals or hardy perennials.

They are commonly known as Woodruff or Sweet Woodruff.

The annuals tend to flower in the middle of summer, whereas perennials tend to flower in the spring.

Asperula odorata - Sweet Woodruff

Description of Asperula species such as Woodruff

Woodruff are small spreading plants that make a great plant for rockeries. They can also be used to cover bare ground.

Asperula usually have tiny flowers of pink or white.

Asperula Arvensis by Alexandre Dulaunoy.

How to Grow Asperula

If growing annual varieties of Asperula outdoors, it is best to pre-chill the seeds about ten weeks before sowing out in the spring. Perennial varieties can be planted out in the spring beginning of summer.

Woodruff typically takes about 3 to 6 weeks to germinate. Seeds should be sown in pots, then wrapped in a plastic bag to protect from light; the tray should then be refrigerated for about two weeks.

Following this imbibing process, the tray should be placed in light at a temperature of ten degrees Celsius.

Seedlings should then be transplanted after the last frost of winter or spring, smaller species of Asperula should be spaced at about four inches (10 cm), whereas larger Asperula varieties should be planted about eight inches (20 cm) apart.

Ideally they should be planted into a soil which is acidic in nature (pH 4.5 to 5.5); the soil should be moist and humus rich.

Caring for Asperula

The Asperula plant is pretty easy to look after; if you plan to use the leaves for cooking, then the leaves should be harvested before flowering has occurred.

It is best to grow annuals from seeds, but perennial varieties can be divided in the spring or autumn to create more plants.

Common Questions

How many members does the Asperula genus have?

The Asperula genus consists of about 195 species.

Do members of Asperula make a good garden or landscaping plant?

Yes, some species of Asperula make good ground cover plants, such as Asperula odorata, also known as woodruff, which has sweetly scented leaves and small white flowers.

Which Asperula species are most frequently grown by gardeners?

Asperula odorata, also known as sweet woodruff, is a popular choice for gardeners due to its charming white flowers and its aromatic leaves, particularly when dried.

Are members of the Asperula plant genus fragrant?

Yes, some Asperula species are fragrant. Notably, Asperula odorata or sweet woodruff, is known for its sweet, fresh smell, particularly when the leaves are crushed or dried.

What is the perfect location to grow Asperula?

Asperula prefers shady locations and moist, well-drained soil. It's a good choice for woodland gardens or as ground cover in shady areas.

Is Asperula invasive in the USA, if so in which states?

Currently, Asperula is not listed as an invasive plant in the USA.

How do I remove Asperula plants from my garden?

Asperula plants can be manually removed by digging up the plants, making sure to remove all the roots to prevent re-growth.

Summary

The Asperula genus, part of the Rubiaceae family, contains about 200 species of annuals and perennials. The most well-known species is Asperula odorata, also known as Sweet Woodruff. Native to Europe, North Africa, and Western Asia, these plants are grown for their whorled leaves and small, star-shaped flowers.

Asperula plants thrive in part shade to full shade and prefer moist, well-drained soil. They are often used as a ground cover in woodland gardens or shady areas. Sweet Woodruff, in particular, is known for its sweet scent, especially when the leaves are dried, and is often used in potpourris.

I hope that you enjoyed this guide on how to grow Asperula plants. You may also enjoy the following Gardener's HQ growing guides: Growing Ixora coccinea, Mitchella, and Phuopsis plants.