How to Grow and Care for Sedum (Stonecrop)

Sedum is a large genus of flowering plants that is found on almost every continent. The plants come in a wide variety of heights, colors, and forms. Also known as stonecrop, most sedums are hardy, drought-tolerant succulents with thick, fleshy leaves that vary in shades. They typically have tiny, star-shaped flowers that bloom late in the growing season.

In general, the genus is divided into two categories: low-growing sedum and upright sedum. The low-growing sedums stays short and spread, whereas the upright sedum forms vertical clumps and looks great along borders and in flower beds.

Several plant species that were previously classified as sedums have been reassigned to new genera. One of the best-known examples is the popular 'Autumn Joy' sedum whose botanical name is now Hylotelephium 'Autumn Joy.'

Sedum generally has a moderate growth rate, but this depends on the species and variety.

Sedum Care

Because they look good all throughout the growing season, thanks to their interesting foliage followed by flowers, sedums also make long-lasting cut flowers and are great for attracting butterflies and other pollinators to your garden.

These plants are extremely low-maintenance. They don't need deadheading (removing spent blooms), and they often look good even into winter. However, extreme heat and a lack of sunlight can cause sedum plants to get a bit leggy. Cutting back the plants after they are done flowering helps to maintain their shape and encourage bushier, sturdier growth.

Planting

The best time to plant sedum is in the spring after the danger of frost has passed but before the summer heat arrives. Simply situate them in a spot that has good soil drainage and adequate sunlight, and they'll practically take care of themselves. Sedums are suitable for mass plantings, as edging and groundcover, and for growing in containers. Water newly planted sedums regularly until they are established.

Light

Most sedum plants grow best in full sun, meaning at least six hours of direct sunlight on most days. Some varieties tolerate partial shade, though they often won’t be as sturdy or bloom as profusely as they would in full sun. However, in very hot, dry conditions, many sedum varieties do appreciate a bit of afternoon shade.

Soil

In general, sedum prefers a loose loamy, sandy, or gravelly soil with sharp drainage. When the soil retains too much water, as is often the case with a heavy wet clay soil, this easily leads to root rot and fungal diseases for sedum.

Water

Water new sedum plants roughly once a week during the first year to prevent the soil from drying out and give young plants a good start. Once established, sedum plants typically won’t need any supplemental watering unless you have a long stretch without rainfall and/or very hot temperatures. Thanks to their thick succulent leaves, established sedum plants have good drought tolerance.

Temperature and Humidity

Growing zones vary by sedum species. But in general, these plants tolerate a wide range of temperatures, though very high temperatures (above 90°F) may lead to scorched leaves. Sedum plants also usually tolerate humidity well, but space plants well for good airflow to avoid powdery mildew. However, excellent soil drainage is especially important in areas with high humidity to prevent the plants from sitting in too much moisture. 

Fertilizer

Sedum typically needs no supplemental fertilization and tolerates nutrient-poor soil. In fact, soil that is too rich causes weak, leggy growth. If you have very poor soil, mixing some compost into it will generally be enough to give your sedum a boost.

Types of Sedum

There are several hundred species of sedum and even more varieties, including sedum groundcovers and upright types. Many species and hybrids have been moved from the genus Sedum to other genera, but since they are still referred to as sedums by nurseries and home gardeners, they are included in this list of popular varieties:

• Hylotelephium 'Autumn Joy', one of the most commonly grown sedums which is now botanically classified as Hylotelephium. It blooms in the fall with tiny pink or rusty red flowers.
• Hylotelephium spectabile 'Brilliant' stands out with blooms that are a truer pink than most sedum flowers.
• 'Vera Jamison' is a Hylotelephium hybrid with burgundy leaves and mauve flowers. It has a trailing growth habit.
• Hylotelephium spectabile 'Black Jack' is a patented hybrid with deep burgundy to almost black foliage and a compact, strong upright growth habit.
• 'Soft Cloud' is a patented hybrid that grows in mounds of gray-green foliage, and its flowers bloom in the late summer with a light pink color before deepening to red.
• Sedum rupestre 'Angelina', a low-growing groundcover sedum with yellow flowers

Pruning

Other than removing any broken or diseases stems, sedum does not require much pruning. In cooler climates, sedums that die back in the winter benefit from removing all the dead plant parts in the early spring to make room for new growth.

If a sedum grows taller than you prefer or looks leggy, pinch off the stem at a growth point in early summer to create a bushier plant. It does delay flowering, but it will create a fuller, more vibrant plant.

Propagating Sedum

Provided its propagation is not prohibited because the variety is protected by a trademark or a plant patent, you can propagate sedum from stem cuttings, which is easy and has a good chance of success:

1. With clean, sharp pruners or a knife, cut a 4- to 6-inch piece from a healthy stem. Remove the bottom leaves.
2. Insert the cutting in a 4-inch pot filled with soilless potting mix. Water it well and keep it evenly moist.
3. After a few weeks, you should see new growth, which indicates that the plant is rooting. Gently tug on the plant. If you feel resistance, it tells you that roots have formed.

Alternatively, divide sedum plants to make more plants. Older plants dying in the center and leaving a hole is an indication that they need to be divided. The best time to divide plants is in the spring when new growth starts:

1. If the clump is large, water it well before dividing it, which makes it easier to lift it out of the ground with all its roots.
2. Remove the entire clump with a garden spade and separate it into individual sections with a trowel, or with pruners.
3. Replant the sections in a new location at the same depth as the original plant. Water thoroughly and keep the soil moist at all times until you see new growth.

How to Grow Sedum from Seed

Most sedum varieties grown in home gardens are cultivars and their seeds won't produce plants that are true to the parent. Therefore it is not recommended to use sedum seeds for propagation.

Potting and Repotting

With its shallow roots, sedum is a good choice to be grown in containers, as long as they provide excellent drainage and you are using well-draining potting mix or succulent potting mix. The container size depends on the height and spread of the variety. Combine smaller sedums with other plants in larger planters. Taller sedum varieties should be grown in terra cotta pots, or other material that has some weight, so they don't topple over easily.

Repotting depends on the growth rate of the variety. A sure sign that it's time to repot the sedum is when the plant becomes root-bound, or the roots grow out of the drainage holes of the container.

Overwintering

Depending on the variety, sedum is a very hardy plant and does not need protection even in climates with harsh winters. The only exception is when the plant is grown in pots, as the roots are only surrounded by a thin layer of soil, unlike in a garden bed. Wrap the containers in burlap and bubble wrap, or place them in an insulating silo over the winter.

Common Pests and Plant Diseases

Sedum has generally very few pests and disease problems. Occasionally slugs and snails might feed on the plant. In poorly drained, wet soil, it is prone to get crown rot.

How to Get Sedum to Bloom

Failure to bloom is mostly due to lack of sunlight although sedum grows in partial sun. Too much water is another cause of reduced bloom.