Sedums are a low-maintenance plant that requires only minimal attention. Check the soil moisture level before watering; sedums only need to be irrigated when the top inch of soil is dry.
Creeping varieties do not need staking, but clumping varieties can become floppy if they don’t get enough sun or nitrogen fertilizer. Pinching living flower stems helps keep them erect.
Choose the Right Soil
For sedums to grow, they need a well-draining soil that has some organic matter in it. Incorporate some well-rotted manure or compost to improve the quality of your soil and add nutrients, if necessary. Use a soil-testing kit or meter to determine the acidity or alkaline level of your soil.
Sedum seeds should be scattered over the surface of the soil and covered with a thin layer of vermiculite to prevent them from washing away. Cover the container with glass or white paper and a cloche to help retain heat and moisture. Once the seeds sprout, remove the covering.
Sedums are drought tolerant and require minimal watering, but do not overwater. A few times a week is adequate, or when the top inch of the soil feels dry. For the best flowering, plant sedums in full sun. Some sedum varieties with colorful blooms include Lime Zinger, which has dark green leaves and pink flowers, Touchdown Teak with its purple flowers and rosy foliage, and Pink Bomb with its explosion of rosey blossoms.
Select the Right Container
Some sedum varieties need to be planted in the ground, while others grow well when placed in pots. No matter which type you select, be sure to use a container that has drainage holes in the bottom. Sedums prefer to have dry, slightly sandy soil that is free from organic matter and has a pH of about 6.0.
If you plant sedum in the ground, choose a sunny spot with well-drained soil. Some sedums require full sun, while others tolerate partial shade.
If you plan to plant your sedums in containers, incorporate coarse sand or gravel into the mix to help improve drainage. Be sure to choose a large container, as the plants will expand quickly once they are established. If you are growing sedum seeds, cover the container with plastic wrap to keep it warm and moist. After a few weeks, sedum seeds should begin to germinate. Once the seedlings are ready to transplant, harden them by exposing them to the outdoors for shorter periods of time until they adjust.
Properly Space the Plants
Sedums do well in containers, especially the low-growing varieties that make excellent ground cover. They also look good in strawberry pots, pallet gardens and rock wall and wall garden plantings. When planting them in the latter, be sure to use a potting mix that will retain water and drain well.
Both tall and creeping sedums benefit from deadheading. This can give them a neater appearance and extend their blooming season. Removing wilted flowers can also help reduce the spread of plant diseases, such as stem rot caused by the fungus Sclerotium rolfsii.
When planting in the landscape, tall sedum cultivars like Autumn Joy can put on quite a show as fall turns to winter with their reddish-pink or purple flower heads. They also make attractive cut flowers. If your border sedums tend to flop open from the middle, try giving them the ‘Chelsea chop’ in late May by cutting half their stems back to ground level – this should make them less floppy.
Sedum plants are drought tolerant succulents and should only be watered during the growing season when they need it. Watering them too much can cause the roots to rot. To water them, use a soaker hose or similar method to allow the soil to soak up the moisture, rather than splashing it onto the leaves and stems. It is a good idea to fertilize the plants during the growing season with a liquid plant food mixed in with the water. However, too much fertilizer can make the plants leggy and less colorful.
If you’re using the tall varieties as ground covers, they should be spaced 1 to 2 feet apart. Low-growing, creeping sedums should be spaced 6 to 12 inches apart.
Clumping sedums often need staking. If they don’t have enough sun or receive too much nitrogen fertilizer, they can become floppy and may need to be supported with twine or low metal wire. This can be done before they flower so the supports aren’t in the way of the blooms.