The Agave Macroacantha [a-GAH-vee, mak-roh-uh-KAN-tha] has a common name of Large-Thorned Agave or Black-Spined Agave.
It is a species of the succulent Agave plant family popular plant in pots and the landscape.
The plant belongs to the Asparagaceae family (Agavaceae) and is native to the Oaxaca region but some species have been naturalized to North America.
Some naturally occurring agave plants are also found in the State of Puebla in Mexico in the small town of Tehuacan.
Macroacantha is one of the many lesser known Agave species including:
- Agave besseriana
- Agave linearis
- Agave pugioniformis
- Agave subfalcata
- Agave integrifolia
- Agave oligophylla
- Agave flavescens var
- Agave sudburyensis
- Agave paucifolia
- Agave Macroacantha Viridis Hort
Agave Macroacantha Care
Size & Growth
- The Agave Macroacantha plant has medium-sized leaf rosettes.
- They grow on stems of approximately 23” inches in very dense clumps.
- The wide rosettes grow at the center of the plant among wide leaves up to 1.8′ feet long.
- The narrow blue-gray leaves have sharp 1” inch black terminal spines at the tips.
- Agave plants aren’t difficult to grow.
- They grow slowly and actually thrive when the owner neglects them slightly.
- The plant is perfect for new gardeners or those who want plants but aren’t enthusiasts.
- Leaving the Agave alone on a sunny window is the best way to ensure the plant grows to its maximum potential.
- However, Agave plants are known to get big and will outgrow most indoor rooms.
- The Agave also begins to form a colony with offsets.
- The sap of the plant is an irritant and the sharp thorns can cause injuries if people aren’t careful.
Flowering and Fragrance
- The flowers of the Agave have a purplish-green color, usually small, with no distinct scent.
- They have a fuzzy interior and grow in bunches which look very pretty.
- The plant only begins to flower once it has matured which can take 15 years or more.
- Macroacantha plants bears fruit which resembles capsules and grows to almost an inch in diameter.
- They are dark brown and oblong in shape.
- The blooming season of the plant is from spring to summer.
Light & Temperature
The Agave plant has proven to be a hardy plant.
It’s possible to grow the plant in one of the coldest regions and it will remain unbothered by temperatures as low as 20° degrees Fahrenheit (-7° C).
Sometimes, temperatures below 25° degrees Fahrenheit (-4° C) or above 115° degrees Fahrenheit (46° C) can injure the plant.
The plant prefers full sun but for western hot sun, it is better to have light shade.
Watering and Feeding
Mature plants of the Agave are drought tolerant and can even survive low desert habitats.
When you first move the Agave outdoors, watering it once every 4-5 days for the first month is enough.
Eventually, you will only need to water it every other week depending on the weather.
They only need supplemental irrigation in summer months to ensure the plant remains healthy.
Watering too much in winters will cause the roots to freeze up.
NOTE: Overwatering can lead to Agave Root Rot.
There is no need to feed the Agave plant at all. They are known to take care of themselves.
Soil & Transplanting
- The Agave Macroacantha needs to be planted in well-drained soil with full sun.
- They thrive in Hardiness USDA zones of 9 among cacti.
- If you live in hot desert areas, make sure to plant it in a light shady area.
- The plant will need light irrigation running through the soil in coastal areas.
- In warmer inland areas, it is better to irrigate occasionally.
- Pots need more grit in the soil or cactus mixture.
- Add pebbles or small rocks to increase the drainage capabilities of the plant.
- The Agave doesn’t need to be repotted each year since they grow slowly.
- It takes them a long time to outgrow the pot.
Grooming and Maintenance
If growing in containers replenish the soil yearly.
Remove dead leaves as they emerge.
Replant or remove pups to prevent them from choking the parent.
How to Propagate Black-Spined Agave
It’s very easy to propagate by dividing the plentiful basal offshoots of Agave.
You will need a good pair of thick leather garden gloves to protect you from the sharp spines.
It’s uncommon to sow seeds or use the roots of bulbils to grow a new Agave.
Thorned Macroacantha Agave Pest or Diseases
The Black-Spined Agave is a pretty hardy plant and has no known serious diseases or pests.
However, one should always be on the lookout for the snout nosed agave weevil.
The sharp spines could be a problem in an area where there is a lot of foot traffic.
Large-Thorned Agave Uses
The Black-Spined Agave is usually used for ornamental purposes in containers, xeriscape plantings, rock gardens, and landscape borders.
They’re striking plants in colonies, used for accents in many gardens.
They also provide foliage color all year long, which is perfect if you want an evergreen garden.