This is a very complicated topic because everyone has different climates. This guide is going to be very simple and generalized. We're basically going to suggest plant families that would be good for your area outside. Those of you who have experience in growing cactus and succulents are encouraged to contribute growing information about your locality.

Definitions:

• North means any state that has hard sustained freezes in the winter. New York and Minnesota would be examples.
• Southeast means any state that has mild or no winter frost, but high rain fall levels, say greater than 2 inches per month. Florida and Hawaii would be examples.
• Southwest means any state that has a desert climate with low rainfall, extremely hot summers and temperatures that regularly drop below freezing during the winter months. New Mexico would be an example.
• Mediterranean climate is basically coastal California; typically, characterized by wet winters and dry summers and rare frost.

North: Here's the list of cactus and succulent plants recommended for growing outside in the North.

• Agave parryi and all of its variations, A. neomexicana, A. parrasana, A. harvardiana, A. lechuguilla, and A. montana.
• Most Echinocereus from Northern Mexico and Southwest USA. Examples would be Claret Cups.
• Opuntias. Some species of this cactus grow all the way into Canada. Most will lay down flat in the winter, then erect back to life the following spring. Most have beautiful flowers ranging from yellow to pink in the sping.
• Yuccas. They look like palm trees but are very cold hardy. Examples would be Y. rostrata, Y. thompsoniana. Most are hardy to well below zero degrees F.
• Manfreda, which is an American deciduous succulent that comes back every year.

Southeast: Here's the list of cactus and succulent plants recommended for growing outside in the Southeast. With fast draining soil, just about any succulent plant should do well here. Wouldn't recommend cactus because they rot easy. You can try Aloe, Agave, Crassula, and Alluaudia to name a few. If your are in an extremely high rain area, say 4 inches per month or more, you'll want to protect cactus and succulents from excessive rain. You can place them on your roofed patio.

Southwest: Here's the list of cactus and succulent plants recommended for growing outside in the Southwest. Most cacti. The only cacti that may need winter protection are those from Baja California and some South American cacti.

• Ferocactus
• Echinocereus
• Echinocactus
• Cereus types (columner cacti) including Oreocereus, Saguaro, Cereus peruvianus, Trichocereus, and Stetsonia.
• Yuccas as above.
• Agaves. Here I would recommend staying away large leafed agaves. They tend to get attacked by agave larve in the hot summer months. You'll want to use small ones such as Agave parryi and all of its variations, A. utahensis, A. parviflora and its related species, A. pelona and A. ocahui, and A. victoria reginae.
• Some Aloes do well in the desert. But some need sun protection and others need cold protection.
• Some succulents not recommended for the desert are echeverias and crassulas. They tend to melt in the hot summer heat.

Lastly, Mediterranean climates can grow just about anything. I would split this area into two sub climates: North and South. North of San Luis Obisbo on the Central Coast of California, the winter rain fall is much higher than south of San Luis Obisbo. I would tend to stay away from cacti growing outside in this area. The crassula family does well here as there are many types that grow natively in this area. There are also many micro-climates along the North Coast, such as the San Francisco climate in which get very cold and foggy summers. There may not be enough sun and heat for some cactus and succulent plants to thrive. However, one species of aloe really loves this climate. That is the aloe polyphylla, also known as the Spiral Aloe. It has a maximum sustained temperature of 95 degrees F.

Southern California is like heaven for most plants. You can grow just about anything outside. Your only concern in California are pests. Because of the mild temperatures and wide spread agriculture, the imported Argentine Ant has just about colonized the state. The ant is very efficient at farming other insects such as aphids on your expensive plant collection. If the parasites are not kept in check, they can destroy your collection.

Website recommendations. Try desert-tropicals.com for max and min temperature requirements of plants. Try cactus-mall.com for a list of nurseries and lots of other information. Yahoo groups has many chat groups for various cactus and succulent plants. You'll want to join the one most appropriate for the type of plants you are interested in. You'll meet other experienced gardeners that can answer your specific questions. Agaveforum, Fat-Plants, Haworthia, and Cactus_Collections_and_Xchange are some of the yahoo chat groups that are very active.

In summary, this is a very small bit of information on selecting cactus and succulents for your garden. Hopefully, those of you who have experience growing in harsh invironments can share your knowledge and inhance this guide.