Cacti are a group of succulent plants that have remarkable adaptations to survive harsh and often inhospitable conditions. They are usually without foliage and have thorns (spines) for protection and as a moisture conservation method. The spines are essentially modified leaves. The thick stems of plants have a waxy outer cuticle that also helps conserve water and acts as a moisture storage organ. Cactus root systems are also impressive adaptations that help the plant survive arid areas where heat is high.
Characteristics of Cactus Root Systems
Cacti live in some of the harshest growing conditions. They face periods of extreme drought and high temperatures. Cacti need moisture and nutrients like any plant, but the poor soils and the dry, cracked texture of it that seeps out moisture and nutrients in rare periods of rain pose challenge. Cacti are uniquely adapted to store these essentials and to collect them through a root system that is both small and shallow but effective.
Cactus roots are covered in a cork-like layer that prevents water loss. Some cacti have tuberous roots that are thick and fleshy, and act as storage organs for food and water. Most cacti have fibrous root systems that spread and are made of connective tissue. Both types of root have fine absorbent hairs that line the outside of the plant. Root hairs emerge from the tips of the roots and are shed and replaced by new ones as the roots grow.
Parts of the Cactus Root System
In order to survive in diverse substrates and terrains, cacti have developed roots that allow them to take advantage of their environment and survive where the most resistant ones could not. Each root corresponds to a particular type of need of the species. Are cacti common in arid and desert areas of America? Yes. Do cacti grow only under these conditions? The answer is NO, and this is something that is often forgotten. There are varieties that belong to high altitude areas (cold and dry) and even humid.
Here we mention the most frequent types of cactus roots, classified according to their shape.
A taproot is a characteristic of some root systems that occurs in plants that live in dry soils or that are tall and require a dominant root as an anchor. Many tall cacti grow one or two taproots that can penetrate the ground for many yards. Deep roots can find deeper sources of water or nutrients and can shrink when there are periods of drought.
Cacti with this root have a stronger hold on the soil and seek nutrients and water deeper than most. When growing, deep and wide pots are recommended if you want them to grow to a large size.
Most cacti have wide-spread root systems. Some cactus roots can grow up to 15 feet from the base of the plant. These roots are close to the surface of the soil and help the plant to collect water quickly if it rains. During a rain shower, roots that had been filled with wrinkles rehydrate and start working and new lateral roots were quickly formed to get every last drop of moisture on the plant. The roots wither again during dry spells and those new lateral roots will fall off the plant.
Different roots very similar in thickness and of equal importance start from the cactus. These predominantly extend in the superficial layers of the substrate, so they do not penetrate to great depth. They are adapted to quickly absorb the water that the soil receives, so covering more ground guarantees them more hydration. They thrive in wide pots.
“Turnip” shape, they are distinguished by a wide main root that accumulates liquids and that becomes narrow towards the end. From this, secondary roots grow that do not reach the thickness of the main one. Cacti with these roots are ideal in a deep pot and they handle quite well with little watering.
They grow downward, branching and have a great thickness, similar to tubers. Their storage capacity is considerable, in addition, they can grow thin and extensive secondary roots.
A deep pot is also recommended. Although the napiform and tuberous roots do not really reach great depth, this type of pot allows greater freedom to the cactus and facilitates the growth of the roots.
Pruning Cactus Roots: Is it Recommended?
In the care of cacti, the roots rarely come into focus. If, on the other hand, the change to a new pot is on the agenda, cactus gardeners wonder whether too long root strands or a dense root braid can be cut.
Roots are the lifelines of all plants. Cacti are no exception in this regard. The root system usually consists of shallow or deep-reaching main roots, which are equipped with a dense network of fine and hair roots. In this way, water and nutrients get into the ducts where they are processed.
Hair roots on cacti usually only live a few hours or days. The lifespan of fine roots is also very limited in time. Numerous species of cacti shed their tender roots in the dry and form them again if necessary. Intervening in this cycle with the scissors requires careful consideration and should only be done in an emergency.
If pruning cactus roots, make sure of the following steps:
- Disinfect pruning tools
- Cut off dead roots down to the healthy tissue
- Dust cuts with cinnamon powder
- Let dry for 3 to 4 days in a shady location
After potting the cactus, it should recover from the strain at the semi-shady, warm location. Only after 2 to 3 weeks water the plants for the first time.
Taproots or main roots should be spared from a cut. Small species, such as Yavia cryptocarpa or Blossfeldia liliputana, do not survive this procedure.