Succulents encompass the thick leaved varieties such as aloe and sedum but also the pricklier side of plants as in cacti and Euphorbia. Their outstanding feature is their drought tolerance which stems from the plant's ability to store moisture for long periods. The plants can be found in almost every area of the world, from deserts to mountains and anything in between. The key to successful succulent landscaping is to choose the correct variety for your zone.
Broad-leaf succulents such as agave have a hardiness range to zone 5 and the form, Agave palmeri can with stand temperatures down to 10 degrees Fahrenheit. Sedums are some of the toughest succulents and many can survive in the United States department of Agriculture zone 3. Cacti are succulent and bring into the landscape the stark romance of the desert. Some of the most cold hardy succulents come from the Prickly Pear family Opuntia. There are species in this family that can thrive down to -25 degrees Fahrenheit such as Baby Rita Prickly Pear.
Other hardy cacti to include are the Corynopuntia, Escobaria viviparia, Cylindropuntia and Echinocereus or hedgehog plant. The classic hens and chicks do very well in cooler zones as does the ice plant which can create a thick succulent mat of flowering pads. Try some Autumn Stonecrop, Artichoke Agave and Echeveria for a composed planter that will survive light snows and freezes. Yuccas are a classic shape with magnificent spear-like foliage that is cold hardy to the 20's or more with some protection.
Once you choose your succulents you need to know how to care for them. Plant them in full sun where the soil has extremely good drainage. The addition of some grit can help ensure the soil percolates and the plant's roots won't stay too wet. Avoid areas of the garden with rich loamy soil unless you amend it with sand or grit. Containers work well for succulents, too. Choose a pot that is unglazed so excess moisture can easily evaporate from the clay. Most succulents do well without fertilizer but you can give them a spring dose of a cactus formula for added nutrition.
If you are worried about the possibility of frost damage in-ground plants can be briefly covered until dangerous cold temperatures pass. Use frost cloth or even an old blanket provided it isn't too heavy. Remove it during the day so the plant can breathe and collect solar energy. Container plants are even easier to protect by setting the pot on a dolly and rolling it into the garage or other covered structure. Avoid watering succulents and cacti before a freeze is due. Should freeze damage occur, symptoms show as lighter white to yellow regions on the pads or foliage. In most cases the damaged area will turn black, dry out and fall off. The worst situation is freeze damage to the stem or root area. Recovery from such conditions is limited and almost always results in plant death.
Northern and temperate gardeners take heart. There are plenty of succulents for your region. Be creative and make a display that showcases the wondrous forms and shapes of these hardy plants.