Colorado has cacti in considerable abundance and our " 
species are almost all new in collections. " A 'N / Manual 
of Rocky Mountain Botany :f by Coulter and Nelson lists 
the following: 
MamiHaria-4 species 
JJchinocactus-- — 3 gpecies 
3chinocereus -- 5 species 
Opuntia - 11 species 
ye do not handle all of these 23 kinds since some are 
rare and others are 30 nearly alike that there is no 
reason for handling several. 
All cacti native to Colorado grow in a high altitude with 
hot dry summers and cold variable winters. Our cacti are 
frost hardy and withstand cold as extreme as 30 degrees 
below zero when in wilted condition. They become firm 
again with the warm spring rains. It is reasonably safe 
to say that Colorado cacti will withstand the cold in 
many regions. In their native state there is little 
winter moisture so that in moist climates they will need 
protection against too wet a soil. They should enter 
winter in a somewhat wilted condition, accomplished by 
withholding some water. Give as much strong sunlight as 
possible. Cacti are of easy cuLture and give a wealth of 
blossom and an interesting plant growth for a minimum of 
attention. The natural soil is dry and low in organic 
matter but yet\fertile. Much is written about soil for 
cacti but remembering the above will enable a person to 
use something at hand. . CLays hold too much water, coarse 
sand not enough water. Most soils between these extremes 
can be used if ivell drained. Cactus soil should be free 
from a Lot .of fresh organic matter, yet a Little v/eli- 
rotted organic matter and some commercial fertilizer is good 
since the cacti naturally grow on a fertile soil. 
Give a cactug good drainage and water infrequently, in 
winter espe'cially. Yet do not expect a cactus to thrive 
without watfer. They need more water in a pot than when 
planted iry the open. A good idea for a potted plant is to 
3et the pot on a saucer -well fiiled with sphagnum Tsf peat 
moss. A cactus can be killed by drouth but a temporary 
lack” ,oT water fits the natural conditions better'. Ours 
