For Portland Conditions
First, what makes a plant succulent? These plants come from hundreds of plant families, being found around the world, in just about any climate. The defining characteristic is their ability to store water for the dry spells, which kill many an ordinary plant. These plants also have the ability to carry on photosynthesis, even when pulled from the ground or cut to pieces. This mechanism, known as the Crassulacean Acid Metabolism, or CAM cycle, literally allows a cutting to survive weeks or months of being uprooted.
This ability to survive also leads to a liability, the inability to transpire or breathe. Most plants have stomata or pores--for the release of water and absorption of oxygen--under their leaves. Cactus and succulents have reduced stomata. This means that the plant cannot rid itself of excess water easily, but instead must metabolize it--which it can only do when warm enough to initiate photosynthesis. This tells us what we need to know to ensure happy plants:
In a humid environment, as most of the Northwest is, the plants cannot handle a heavy, hard to drain soil. We use 70% aggregate (1/4 to 3/8 inch red lava or pumice) and 30% premium potting soil . This does NOT include fine sand, which holds water.
All plants need water--but ours like to dry out between waterings! Let the plant dry out until a tester says there is no water left. You can also use a pencil to check if your plant is dry. Push the pencil to the bottom of the pot, if it comes out clean it is dry. It is like checking a cake with a toothpick. When it is hot, water generously, when it is cold you must leave the plants dry long enough to utilize its stored water. If you are not sure, don't water until it looks dry. Then increase the watering slightly, until you find your plants watering requirements for the environment you have provided. We also reduce our watering in the winter by using a spray bottle. One of the problems is the soil does not dry out fast enough, so the plant rots from the bottom up. By watering the top of the soil and the foliage only you insure the plant drys out more quickly. With Caudiciforms when it is hot water every 7-10 days and in the winter every 4-8 weeks.
All plants need food. Best results will be had if you feed every other watering in summer, with a 5-5-5 to 7-7-7 fertilizer. Light and heat are both necessary for good growth. Take a cue from the plant...if it has a soft green skin, it needs protection from the direct rays of the afternoon sun. These plants will scorch! However, if the first impression is of dense spination, this plant carries its own shade with it, and can stand full sun, even in the desert.
HOW TO GET YOUR CACTUS TO BLOOM--Cacti, like people, need a GOOD DIET and a REST PERIOD. Allow your cacti to REST for at least 2-3 months during the winter by putting them in good light and keeping them dry and cool (40-50 degrees) with good air circulation. During the rest of the year, water from the soil surface so it drains out the bottom of the pot. Feed during the growing period which is generally April through September A balanced (20-20-20) fertilizer or Miracle Grow at 1/4-1/2 strength every other watering is a GOOD DIET. Generally, water every 7-10 days when it is hot IF your plants are dry, except with epiphyllum (orchid cactus) they like to keep their roots moist. In winter water every 4-8 weeks after the rest period. Since the stomata of cacti open in the evening, watering and feeding as well as treating for pests should be done late afternoon or evening. One soil mixture is 2/3 pumice sifted + 1/3 potting soil.
LITHOPS
--Lithops perform all of their needed functions solely on the juices stored for the winter months. They will send up new growth, in the form of new pairs of leaves, right through the center of the old leaf pairs. All in all, they are the very picture of an active growing plant. Do not be fooled; they absolutely expect NO outside help, certainly no water, and will die from fungal growth if they do get wet! When the old leaves are totally papery--that is, dry and brittle--and the side skin is wrinkled usually about May water thoroughly. Your conditions may be hotter or dryer, water about once a month except when it is very hot then twice a month until your plant flowers about September then stop watering.
ECHEVERIA along with Dudleya, Pachyphtum, and Sedum are the principal members of the succulent New World Crassulaceae. Echeverias come principally from the mountains of Eastern Mexico. Venezuela has a significant population. The genus Echeveria is named after Atanasio Echeveria illustrator of a projected Flora Mexicana. Coming from mountainous regions, Echeveria prefers well-drained soil, and good ventilation. They also prefer cooler temperatures. Echeveria look best in the summer and fall. The plants will take a slight freeze if dry but must come inside for the winter and they will sulk. Propagation of Echeverias is a required skill rather then an optional one. All Echeveria have leaves that dry and fall off as they age, leaving a thick and usually ugly stem. If you clip the tops, Echeverias offset between the older leaves. These offsets can be removed, the bottom most leaves of the offset removed, and the stem and remaining leaves planted as soon as the cut stem is dry. Successful rooting almost always follows. The terminal rosette should also be periodically removed and restarted in the same way, with all the dead and the older live leaves removed. The old stem can be kept for a while, as it frequently offsets from the top or side, and these offsets can be removed as well and propagated. Echeverias have flowers on an extended stalk(raceme). The raceme has small leaves on it, and occasionally, rosettes. These will root easily as well. Echeveria make wonderful landscape plants, and mass use of these are highlights of the gardens at the Huntington and the Getty Museum. The Huntington takes pains to keep the plants out of a formal geometric pattern. The Getty does the reverse, fitting in better with the architecture and design of the gardens at this sit. Both are worth seeing. The same plants are used to very different effects.