Agave lophantha (Thorncrest Century Plant)

Agave Lophantha

Last updated on July 10th, 2022 at 07:31 am

The Agave lophantha, also known as the thorncrest century plant, is native to the mountains of Northern Mexico and Southern Arizona. It grows to an average height of 10–12 feet, though some have been recorded at over 15 feet in height, with stalks that are roughly 5–6 inches in diameter.

Thorncrest century plants can weigh anywhere from 350-600 pounds and can live up to 500 years if cared for properly, making them one of the longest-living cacti species in the world!

Agave Lophantha is an ancient species of agave that only occurs naturally in the Sonoran Desert and one small area in Baja California, Mexico. It gets its name from the spiny crest atop its large rosette leaves, which resemble the thorny crown of an eagle.

Origin and distribution

Agave Lophantha plant is native to Arizona, where it occurs in Pima, Santa Cruz, Cochise and Yuma counties; it may also occur in Mexico. The Thorncrest century plant grows on rocky ridges and canyon walls at elevations of 1,500–3,700 feet (457–1,128 m).

It can be found growing on canyon walls beneath scrub oak trees. This species is a member of a group known as rosette agaves because they produce a rosette of large, fleshy leaves that resemble those of an aloe.

Other members include Agave parryi var. truncata and Agave victoriae-reginae. In addition to its natural range, thorncrest century plant has been planted elsewhere in Arizona and is considered invasive.

Agave Lophantha produces a massive flowering stalk up to 10 feet (3 m) tall with numerous yellow flowers about 2 inches (5 cm) wide. These plants are monocarpic, they die after flowering, and typically flower every 15–20 years.

Flowering typically occurs between March and May depending on elevation; some plants have been observed flowering as late as June or July.

Agave Lophantha propagation

Agave Lophantha

Agave Lophanatha is an awesome cactus/succulent that grows a basal shoot called a pup. You can harvest and plant these pups to create new agaves. This is a great way to expand your garden and try new species since most species of agaves have very specific environmental requirements.

Agave Lophantha plants are extremely easy to propagate, especially through their pups. All you need to do is take a sharp knife or shovel and cut off one of its shoots (called pups).

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Make sure you leave some roots on it so it doesn’t die. Then just stick it in some soil, water it well, put it in indirect sunlight for a few days until it starts growing again, then put it where you want! It should start growing within two weeks or so. If you don’t get any growth after three months, consider yourself unlucky and try again with another pup.

Since they grow slowly, I recommend taking multiple pups from a single Agave Lophantha mother plant every year or two to ensure that at least one will grow successfully. Once it gets too big though, you may want to separate them into individual pots. The best time to harvest pups is when they are about 6 inches tall; before they get too thick and woody around their base.

Agave Lophantha care information

Agave Lophantha

Agave Lophantha plants are some of our hardiest succulents. While they do not like to be subjected to high temps, they can tolerate a freeze or two if properly planted. The defining feature of most agaves is their rosette form. When planting an agave, dig a hole that is two times as wide as your root system and no deeper than 1/3 its size.

Light requirement

Thorncrest century plants require bright light for about 6-8 hours a day. Being outdoors in direct sunlight for 8 hours a day is ideal, but if you can’t provide that kind of light indoors, it’s okay to shorten their daylight period slightly.

A windowsill with eastern exposure and a few afternoon hours of direct sunlight works best in winter months when natural light is limited; in summer you can put them outside and they will be fine as long as they get good morning sun.

Soil/potting mix

The soil must be well-drained, preferably loamy, for young plants; mature specimens can withstand drier soils. Use commercial cactus potting soil, or mix your own by combining 1 part sand, 2 parts loam, and 1 part compost.

Agave Lophantha prefers a slightly acidic soil pH of 5.5 to 6.5. If you have alkaline soil (pH above 7), add peat moss to lower pH, or add sulfur to raise it if necessary.

Watering

Agave Lophantha are quite hardy and not particularly sensitive to water. Water them deeply only once every two weeks during their active growth phase. A thorough soaking of up to one-half of their pot size is sufficient. The rule of thumb is that if your fingers get wet while holding a few inches above soil level, they need water.

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If they don’t, then don’t worry about it for another week or so at least. These plants can go three months without any additional watering, although they will grow more slowly than when watered regularly.

When in doubt, err on the side of under-watering rather than over-watering; these plants can tolerate almost complete neglect but will rot away quickly if over-watered.

Fertilizer

The Agave lophantha is a bulb/succulent plant and as such, needs a lot of fertilizer to keep it healthy. Give your plant fertilizer at least twice a year. Be sure to follow package instructions closely for the best results. To do so, mix granular fertilizer with water in a separate container from your main pot before adding it to your agave’s soil.

This will help prevent burning its roots. Once mixed with water, pour into potting soil until you see no more than 1-2 inches of dirt on top of fertilizer granules; then give it time to work its magic!

Temperature

Agave lophantha needs moderate temperatures. The ideal temperature range is between 24-32 degrees Celsius (75-90 degrees Fahrenheit). If you live in a cooler area, you can keep your agave outside during summer and bring it indoors when nighttime temperatures drop below 24 degrees Celsius (75 degrees Fahrenheit).

Humidity

Agave Lophantha can tolerate humidity very well and is commonly found in places with a high amount of humidity such as rainforests. Although it is known to be able to adapt to many different climate conditions, its main issue is when it becomes too dry for too long.

Since most of its body is underground, its roots are where it gets most of its water from. If there isn’t enough moisture in them, then it will die off from dehydration.

The ideal humidity range is between 70% and 80%. This can be achieved by placing it in a humid room or even a small greenhouse. Humidity levels that are too high, however, will also kill off these plants as they prefer to have their roots dry.

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A good way to check if your plant needs more water is to stick your finger into its soil. If it feels moist, then you don’t need to water it yet. If it feels dry, then you should give it some water right away.

Pruning

Agave lophantha will grow too large if left unpruned. Remove growing tips in late spring to limit its size and encourage branching. To prune it correctly, you’ll need to be familiar with some basics of plant growth: growing points on plants are called apical meristems, which is exactly what it sounds like, the most active growing point on a plant; removing them will stop growth at that area but not kill or damage it.

When to repot

Repot every two to three years in spring or fall. Move the plant into a container one size larger and use an all-purpose potting mix. Cut back on water for a couple of weeks after repotting, and keep the soil lightly moist until roots are well established.

Water deeply and less frequently when the plant is growing vigorously. The best time to fertilize is in early spring before new growth begins. Feed monthly with a balanced liquid fertilizer diluted by half during active growth periods; withhold fertilizer during winter months.

Dormancy/Winter rest

If you live in a frost-free climate, consider moving your Agave lophantha to a cooler place when temperatures drop below 50 degrees. Mature plants go dormant during the winter months and need to be left undisturbed while they’re in winter rest.

If you live in a tropical climate, keep your agave outside year-round. Water regularly, but allow the soil to dry out between waterings.

You can use ice cubes or a misting bottle to increase humidity around your plant if it begins to wilt. Avoid getting water on leaves as it can cause rot.

Your agave will start growing again once temperatures rise above 60 degrees Fahrenheit, which is typically sometime in February or March depending on where you live. In warmer climates, Agaves may start growing as early as January!

Agave lophantha flower & fragrance

The flowers of Agave lophantha bloom in June and have a pleasant aroma. They are generally yellow with maroon petals, but can also be pink or white.

The odor is said to attract bats and it does seem that bats will often find their way to these plants at night because we often see bat guano on top of them after sunrise. This species has been described as having a pungent fragrance by some.

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Growth rate

Agave Lophantha

Agave lophantha is a slow-growing plant that can take several years to reach maturity if it grows at all. After it flowers and produces a large central flower spike or inflorescence, it takes up to a decade for new leaves to emerge. Some of these plants are so old that only narrow rings of new leaves remain around their trunks.

Toxicity

This species has been used for hundreds of years as a laxative, and it does contain saponins. Care should be taken when ingesting agaves in general due to their high saponin content and potential toxicity.

While all plants are toxic in some way, agaves may be more toxic than others because of their high concentration of saponins. Not everyone reacts poorly to saponins.

USDA hardiness zones

Agave lophantha thrives in USDA hardiness zones 9 through 11. In these areas, you can grow it outdoors year-round with no protection. In colder climates, you’ll need to bring your agave inside during the winter months and provide a little extra care to ensure its survival.

Pests and diseases

Though some agaves are fairly drought-tolerant, you’ll want to keep an eye out for signs of pest or disease. Most commonly, it is gray mold that infects agaves and other succulents and can be spotted by yellowing of leaf tips, curling leaves, and blackening of affected parts. Other common problems include aphids, mealybugs, and scale insects.

Conclusion

Agave Lophantha is one of nature’s most unique plants. An early bloomer, it flowers in its second year and can produce a flower stalk that towers more than 5 feet high. In addition to gorgeous flowers, Agave Lophantha produces an attractive rosette of blue-green leaves with sharp, spiny teeth at each end; these have earned it another common name, thorned century plant.