Cactus Gardening

1. Germination

2. Cactus seeds are often distributed by birds, which are attracted to the fruit. Germination occurs in the presence of sufficient water and warm temperatures.

3. Vegetative Growth

4. After seed germination it can take several months for the basic barrel shape of the cactus seedling to become visible. It takes five to 10 years for small species to reach flowering size.

5. Flowering

1. If there has been sufficient rainfall, flowering occurs in most species during the spring, once temperatures are warm enough.

2. Pollination

3. Most cacti are self-sterile, requiring pollen from a different individual plant. Depending on the cactus species, bees, wasps, beetles, butterflies, moths, birds and bats can pollinate cactus flowers.

4. Fruit Formation

5. Cactus fruits are seed-filled berries. They form at the base of the flowers and are often brightly colored and sweet to attract birds.

6. Forced Flowering

7. In cultivation, cactus plants can sometimes be induced to flower by keeping them in a dark place for up to six weeks and then providing light and water.

The tallest type of cactus is the giant saguaro cactus.

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Actually, there are a number of cacti that are either as tall or taller than the saguaro (Carnegiea gigantea). Here are just a few: Cephalocereus, Neobuxbaumia, Neocardensia (now Neoraimondia), Cereus, Trichocereus (now Echinopsis), Isolatocereus, and Pachycereus. The largest cacti in terms of height and weight are Pachycereus, and the largest of that genus are P. pringlei, P. weberii, P. militaris, and the largest cactus on the planet, P. grandis.

The saguaro is just the best known of the large cacti and if you have ever seen one, they are very impressive, as are all of the large cacti!

The main way by which the prickly pear cactus [Opuntiaspp] survives is through growing low to the ground. It does so as a plant that sports prickly pads, or as one that has low branching arms. This particular growth pattern decreases the distance that drops of moisture travel from the plant's modified leaves to the ground, for intake by the plant's roots. It thereby decreases the time during which that precious moisture is exposed to the evaporation possibilities inherent in any interaction with the desert's bright, hot sunlight.

This particular growth pattern also shades the ground immediately around and below the cactus. It cools the soil. Consequently, less encouragement is given to evaporation of water that's on or close to the soil surface. So the measure is a move that conserves water.

Another important survival strategy is through growing jointed pads or branching arms. The joints may break off and fall to the ground, where they root and thereby form other prickly pear cactus plants. The result may be the formation of an entire community where once there was only one prickly pear cactus.

Still another survival trick is through growing defensive body parts. The prickly pear cactus has modified leaves in the form of barbed spines on the pads, and bristled tufts on the branching arms. Either way, the spines and the bristles discourage predators. They also direct any available moisture - be it dew, fog or rain - to the ground, for intake by the plant's roots.

There are anumber of pests and diseases that cacti can be affected by, and without the details it is hard to tell. Usually, problems are caused by overwatering, lack of sun, low temperatures and a variety of pests.

To help you work out what the problem might be, check the Web Links to the left for more information.

As is the case with all living organisms, a cactus plant can't live without water. Specifically, it needs water to take in the nutrients that it needs to live. Minerals and trace elements in the soil only can be taken in dissolved form by a plant's roots. No water means no nutrients.

Additionally, the dissolved nutrients are needed for the photosynthetic interaction with sunlight. Sunlight and dissolved nutrients yield energizing photosynthetic products such as starches and sugars. So no nutrients means no photosynthetic products and therefore no life sustaining activities within a cactus plant.

Its modified leaves are the most obvious defense mechanisms of cactus plants. They take the threatening form of thorns, spines, spikes, quills, prongs, needles, hairs, or bristles. They're particularly threatening when they have barbed ends that quickly become, and stubbornly remain, embedded in the flesh.

Another defense mechanism is sheath that encases the stem. It's thick and covered with a glossy, leathery or waxy surface that stops water loss and disperses sunlight. The cactus thereby is protected against drying out on the inside and burning up on the outside.

Still another defense mechanism are the guard cells. They're found on either side of the openings to the breathing pores, or stomata. They close to keep in water, and open to let in necessary gases from the atmosphere.

Extended drought causes a succulent's leaves to shrivel.

Specifically, a succulent plant wants to expose the least amount of surface area to evaporation. Decreased surface area reduces the amount of water loss. Shriveling up therefore is a way to have a lesser amount of leaf surface available for water loss to take place.

What happens to a spineless cactus depends upon the kind of cactus and its environment. Going spineless may not be the worse thing that can happen to a cactus. In fact, not all cactus plants have spines. For example, the peyote cactus [Lophophora williamsii] is spineless. Its defense mechanism instead is the powerful hallucinogen mescaline that it contains.