Tough as nails.
All across the desert southwest and Mexico, agaves stand up to just about anything: punishing heat, severe drought and poor, gritty soil.
While the ability to defy those extreme conditions isn’t necessary for survival in Central Coast gardens, agaves do make for some very resilient plant choices.
And choices there are, ranging from little tykes the size of cupcakes to statuesque specimens 10 feet tall.
So Many Uses
Some agaves work well in masses; others as elegant focal points.
All form rosettes of thick, succulent leaves that store water, allowing them to endure long periods of drought. Many bear leaves that are tinged blue or gray; others are striped, in various shades of yellow, pink, ivory, red and gold. Skin-piercing spines line the edges of all but a few.
Altogether, there are more than 100 species of agaves. Most are native to hot, dry areas in the southwest US and Mexico, along with Central America and the West Indies. Here, they shrug off pests, attract hummingbirds when they bloom, and thrive on just a little more than our annual rainfall.
Choosing An Agave
Not long ago, agaves were most often available only in tiny pots from specialty growers.
But the current craze for succulents means the supply of agaves has grown much larger. The plants themselves are larger as well.
Instead of wee, little 2-inch and 4-inch specimens that could take 10 years to gain any substantial size, agaves are now offered in everything from one-gallon containers to 36-inch boxes.
But be sure to check the tag, as the size of the agave in its nursery container may have little to do with its size at maturity.
That sweet, unassuming white-striped century plant (Agave americana ‘Mediopicta Alba’) in a one-gallon pot will swiftly grow into a sculptural accent more than 4 feet tall and wide.
The straight species, century plant (Agave americana) grows rapidly as well, and tops out at 10 feet tall and 12 feet wide.
Yet that dainty, white-tipped Queen Victoria agave (Agave victoriae reginae), offered in a one-gallon container, may take a decade to reach only 18 inches wide.
Quick drainage, dry soil and plenty of sunshine are all key to successfully growing agaves. On the coast, look for a spot that gets full sun all day. Inland, provide a little protection from the afternoon sun.
Slopes and mounds are best, where gravity can help drain away water. Avoid low spots, wet spots and anywhere that is regularly irrigated or within range of lawn sprinklers.
Agaves are also susceptible to cold, with the fleshiest types, such as the ever-popular foxtail agave (Agave attenuata) and the plump, gray Agave guiengola turning to mush when temperatures drop to 25 degrees.
If that’s a real threat, select varieties that bear stiffer leaves, stouter spines and waxy coatings on their leaves, such as the small, gray and white King of the agaves (Agave ferdinandi-regis) or the mid-size, wavy-leaved Mr. Ripple (Agave ‘Mr. Ripple). Both are hardy to about 10 degrees.
Another trick is to plant your agaves close to a wall of your house or in a courtyard, where the plants can capture radiant heat released from the structure at night. Or simply plan to cover your agaves with a bed sheet on nights that temperatures drop too low.
Do not enrich the soil. I repeat. Do not enrich the soil.
Too fertile of soil, coupled with too much water, can lead to an early death.
If you have sandy soil, leave it alone. If you have clay soil, mix in perlite or crushed gravel to improve the drainage. Even better, mix in that coarse material, then mound the soil at least 6 to 12 inches high.
Weed the area thoroughly. Then, if you’re planting a larger specimen with bull-goring spines, lay down weed cloth — not black plastic — in the planting area. Otherwise, you won’t have a lot of fun negotiating those spines in order to pull weeds later on.
Cut open slits in the weed fabric to dig the hole. Move the agave into place with heavy-duty fireplace gloves or by wrapping it in layers of plastic bubble wrap or newspaper.
Use wood-based mulch sparingly, or not at all. Agaves, like many succulents, do not like the extra moisture right up against their leaves.
Instead, lay down 1 to 2 inches of gravel, crushed rock, decomposed granite or even decorative, glass pebbles.
Soak your agaves when they first go into the ground.
If you plant this month, water them every week for so for several weeks. By September, let the top inch of soil dry out between waterings. Stop entirely when the winter rains begin. By next year, your agaves may need watering only a few times a month during the hottest days of summer.
If you’ve planted your agaves within a sea of other low-water plants that are already on drip irrigation, then you may add the agaves to the system.
But if the agaves are going it alone, consider hand-watering. If the planting area has much of a slope, be sure to shape basins on the downhill sides of the agaves so that the water doesn’t roll down instead of soaking in.
Agaves can also withstand the overhead spray from sprinklers. But they don’t like to get soggy. And generally sprinklers are used to irrigate lawns, so come on too frequently.
Regardless of your method, do not over water. Unless you see your agaves’ fleshy leaves start to shrivel, they are getting all the moisture they need.
Pups and Flowers
Most agaves send out offshoots of little plants, or pups, around their perimeters. That enables them to produce future generations, because most agaves die after blooming.
Agaves generally live seven to 15 years, depending on the species, with the process taking several months or longer.
For some agaves, including the foxtail agave, the first sign may be an elongating of the trunk.
The agave then typically sends up a single, extremely tall stalk loaded with long-lasting, often cream-colored flowers. Hummingbirds from every corner in the county will zoom in to sip the nectar. As the blossoms slowly drop, the stalk will begin to wither. The leaves then follow, until all that’s left is a desiccated shell of the agave’s former self.
Meanwhile, the pups at the base will have already begun to fill in, continuing the cycle.
Agaves have traditionally been planted in desert gardens.
However, they grow equally well with other low-water plants, including:
• spiky plants, such as kangaroo paw (Anigozanthos) and New Zealand flax (Phormium)
• blooming Mediterranean plants, such as bougainvillea, lavender and sage;
• ornamental grasses, such as blue fescue (Festuca glauca) and fountain grass (Pennisetum);
• low-growing succulents, such as Kleinia, (Senecio mandraliscae), red apple (Aptenia cordifolia) and ice plant (Delosperma, Drosanthemum, Malephora or Lampranthus).
Seeds of Wisdom
Plant spiny agaves away from paths, sidewalks, driveways and patios. They are much better as barrier plants around the edges of your garden, or sited well within a planting bed. Also avoid planting agaves beneath any messy or deciduous trees, as cleaning out the leaves will be difficult.
Copyright, Joan S. Bolton. All rights reserved. Reproduction of text or photos in any form is prohibited without written permission.