Find out how to grow sedums, also known as stonecrop or hylotelephium, in our detailed Grow Guide.
Sedums are succulent plants with fleshy leaves and flat, nectar-rich flowerheads that are loved by bees and other pollinators.
Border sedums, also known as ice plants, have now been reclassified as Hylotelephium. Easy to grow, these sun-loving perennials are a striking feature in late summer, when masses of flat, bright pink flowerheads appear on upright stems. The flowers are extremely attractive to late-flying butterflies and bees. They look especially good planted with grasses such as Stipa tenuissima.
Border sedums look great from spring onwards, as their fleshy green-grey foliage (purple on some varieties) is attractive in its own right. The flowerheads are green in spring, gradually taking on tinges of pink before flowering fully from August onwards. The dead flower heads are worth keeping on the plants – covered in frosts they look spectacular. You can snip them and display them for months in a vase, too.
True sedum, or stonecrops, are small, fleshy-leaved succulents that spread like a mat. They originate in dry, rocky locations, so theyre very drought tolerant. As well as attractive, evergreen foliage, sedums produce small nectar-rich flowers that attract pollinating insects. They make good ground cover outdoors, particularly on green roofs, and are sometimes used as an alternative to grass lawns. The tender varieties make good house plants and can also be grown outside in containers in summer.
Sedum, also known as stonecrop, are popular succulent perennials that provide great late summer color in gardens. Their colorful blooms last well into fall, providing an extended flowering season. However, as sedum plants mature, their tall, top-heavy flower heads often flop over, spoiling their ornamental appeal.
Fortunately, with some easy techniques, you can keep your sedum looking tidy and upright all season long. In this complete guide, we’ll explore the reasons sedum flops over and detail proven methods to prevent floppy sedum growth.
Why Does Sedum Flop Over?
Sedum’s tendency to flop is typically caused by two main factors
Insufficient Sunlight
Sedum prefers full sun exposure and well-drained soil. When grown in shade or dense shade, the stems elongate and weaken, causing the plant to flop over once blooms develop.
Excess Moisture
Overly wet soil leads to lush weak growth that easily flops under the weight of the flower heads. Sedum thrives in drier conditions. Too much moisture encourages floppiness.
How to Prevent Floppy Sedum Growth
Luckily, with proper growing conditions and some simple maintenance, floppy sedum growth can be prevented. Here are the top techniques for keeping sedum upright:
Provide Full Sun
Move potted sedum or transplant floppy plants in garden beds to a location with at least 6 hours of direct sunlight daily. This will encourage shorter, sturdier growth.
Improve Drainage
Incorporate organic matter like compost into dense, heavy soil to improve drainage and aeration Or grow sedum in raised beds for superior drainage
Avoid High-Nitrogen Fertilizer
Fast-release nitrogen fertilizers promote weak, floppy growth. Instead, use a balanced, slow-release fertilizer like Milorganite if fertility is needed.
Pinch Back Growth
Pinching off the growing tips when plants are 6-8 inches tall triggers bushier, stronger growth. Pinch above the second set of leaves on each stem.
Cut Plants Back
For mature, overgrown sedum, cut the entire plant back by half its height in early summer. This rejuvenates growth.
Use Support Cages
Place large sedum inside short support cages. The cages discreetly hold plants upright as they grow.
Stake Stems
Stake any extra tall, weak stems that persist in flopping over. Tie them loosely to bamboo stakes using twist ties or garden tape.
When to Take Action Against Floppy Sedum
To get the best results, intervene early before flopping occurs:
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Spring – Move plants to improve sunlight and drainage issues. Pinch back any overlong stems.
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Early Summer – Cut back overgrown plants by up to 50% of their height.
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Mid Summer – Install support cages before flowers develop.
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Late Summer – Stake individual floppy stems that persist through the season.
Varieties Less Prone to Flop
While all sedum run the risk of flopping over, certain varieties tend to remain more upright. These include:
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Sedum ‘Autumn Fire’ – Upright, large clusters of pink blooms
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Sedum ‘Matrona’ – Taller variety with purple-tinged stems
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Sedum ‘Purple Emperor’ – Deep purple leaves hold colour all season
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Sedum ‘Postman’s Pride’ – Sturdy,wine red stems support pink blooms
When shopping for sedum, look for descriptors like upright, sturdy, and strong to find varieties with better resistance to flopping.
Propagate New Sedum Plants
As you pinch and cut back floppy sedum growth, you can propagate new plants from the cuttings. Simply remove the bottom leaves and stick the cut end in moist potting mix. New roots will form in a few weeks. Then pot up the cuttings or plant them in the garden.
Enjoy Strong, Upright Sedum All Season
With a little diligent care, your sedum plants can put on a gorgeous floral display from summer through fall without falling over. Pay close attention to proper sunlight, soil drainage, and avoid overfeeding.
Intervene at the first sign of weak growth by pinching or cutting back plants to encourage shorter, bushier form. Move plants in time, provide support as needed, and choose resilient varieties.
By following these simple tips for preventing floppy sedum, you’ll be rewarded with beautiful stonecrop that flowers prolifically while maintaining an upright, eye-catching presence all season long.
Advice on buying sedums
- Sedums and stonecrops vary in height so check the height and spread thoroughly before buying
- Always check plants over for signs of pests, disease or damage before planting them
Where to plant sedums
Border sedums (Hylotelephium) need a sunny spot in well drained soil to thrive. Theyre fairly low growing so look best at the front of a border. Try combining them with plants that have different flower shapes, such as spikes or umbels (balls).
Stonecrops need well-drained soil and a sheltered, very sunny site to thrive. A terracotta container or window box would work well, or a roof with a small depth of growing medium.
Sedum ‘Autumn Joy’: Top Tips for Stunning Fall Interest and Preventing Flop
FAQ
How do I keep my sedum from falling over?
Simply pinch each stem back by one third to one half its height sometime in June but before July 1st.
How to prevent floppy sedum?
To keep your clumping sedum erect, especially when flowering, wrap twine or a low metal wire around the plants before they flower.
Why is my sedum falling apart?
Weak stems are the result of overly rich soil. Sedum plants are tolerant of poor growing conditions and even thrive in sandy or gritty medium. Rich and soggy soils will cause the stems to bend and you will see your sedums falling over.