Agave : to plant, to grow and to maintain

Description and Botany

L’Agave est une succulent plant originaire des régions désertiques caillouteuses et montagneuses du Mexique, du sud des États-Unis et des Antilles. Elle fait partie de la famille des agavacées, tout comme les Yuccas ou encore la Tubéreuse.

Le genre comprend plus de 200 espèces, dont la plus répandue dans nos jardins du sud de la France est l’Agave americana, une géante, qui s’est naturalisée aujourd’hui un peu partout dans le monde. Elle est complétée par de nombreuses espèces et variétés obtenues par croisements : l’Agave attenuata peu épineuse et à l’inflorescence en « cou de cygne », l’Agave filifera au feuillage filamenteux, A. ferox et Agave havardiana bordées d’épines féroces, l’Agave victoriae reginae, très remarquée pour ses rosettes de feuilles marginées de blanc ou encore l’agave bleu du Mexique (A. tequilana), qui sert, comme son nom l’indique, à la fabrication de la « tequila ».

L’Agave est d’une croissance plutôt lente mais d’une belle longévité de 10 à 30 ans. Son développement est plus ou moins modéré en fonction des espèces, allant de 15 cm pour Agave parviflora jusqu’à 3 m de hauteur et d’étalement à maturité chez la monumentale A. americana.

Le port est plus ou moins régulier et compact, tout rond, à la géométrie parfaite (Agave victoriae reginae), en forme de coupe dressée ou plus échevelé avec des feuilles légèrement incurvées.

Au fil des années, le buisson s’étoffe grâce à ses rhizomes capables de produire des rejets tout autour de la rosette initiale pour assurer sa pérennité. Elle peut s’avérer envahissante là où elle se plait.

Cette plante grasse diffère essentiellement par le nombre de feuilles qui composent sa rosette.

La silhouette rigide de l’Agave americana contre-balancée par la légèreté des graminées.

Cette vivace impressionnante est très appréciée pour sa silhouette souvent monumentale et toujours remarquablement graphique. L’Agave se développe à la façon d’un gros artichaut ou en bouton de fleur, en rosette dense et radiante, plus ou moins épanouie.

Elle est composée de très nombreuses feuilles crassulescentes, très larges à la base, charnues et coriaces, reposant directement sur le sol, imbriquées les unes dans les autres. Seules certaines espèces comme Agave attenuata s’épanouissent autour d’une tige ou d’un tronc épais ramifié de portant des rosettes.

Les feuilles longues de 15 à 2,50 m, plates, légèrement bombées, sont raides, effilées ou en forme de raquette plus ou moins ovale resserrée à la pointe. Elles sont souvent dentées d’épines acérées régulièrement espacées, véritables dents crochues, de couleur noire, orange-cuivré à rougeâtre, dont on se méfiera. Elles laissent des empreintes sinueuses dans l’épiderme cireux des feuilles voisines.

L’extrémité des feuilles est parfois munie d’une pointe épineuse du même ton. Le feuillage de l’Agave filifera dépourvu d’épines est bordé de longs filaments blancs.

Vert foncé à vert jaunâtre, vert clair marginées de blanc chez l’Agave de la Reine Victoria, gris-vert, bleu-vert bordées de jaune-crème chez l’Agave americana ‘Variegata’, gris-vert bleuté marquées par une bande centrale blanche chez l’Agave du Mexique ‘Alba’, elles prennent toutes les nuances de verts, de gris et de bleutés ou offrent des panachures graphiques. Elles sont souvent couvertes de pruine blanchâtre.

La floraison, toujours impressionnante chez les grandes agaves, n’apparaît qu’une fois que la plante a atteint sa maturité, seulement au bout de 10 à 40 années de culture. Il est assez rare de la voir fleurir en France. Cette floraison annonce la mort de la plante. En été, de hautes hampes florales majestueuses, pouvant atteindre 10 m de hauteur chez Agave americana, naissent du cœur des rosettes.

La spectaculaire floraison de l’Agave americana.

Elles sont composées d’une myriade de petites fleurs tubulaires jaune verdâtre, jaune argenté ou blanc verdâtre, parfois rouges, à six tépales chacune, réunies en ombelles, en grappes ou en panicules. Très mellifères et nectarifères, elles attirent de nombreux insectes butineurs.

Les inflorescences laissent ensuite place à des fruits, dont les graines se dissémineront sur le sol ainsi qu’à des bulbilles qui s’enracineront une fois la rosette affaissée, encore faut-il que votre Agave fleurisse et qu’elle en forme.

Cette floraison aussi spectaculaire qu’unique, épuise la rosette qui l’a fait naître, mais génère la naissance d’un nouveau rejet.  La plupart des agaves ne fleurissent qu’une fois avant de mourir car il s’agit de plantes monocarpiques : les rosettes meurent après la floraison et la fructification, au profit de nombreuses petites rosettes périphériques qui vont s’étoffer et fleurir à leur tour, les années suivantes, assurant ainsi la descendance.

L’Agave est une plante assez frileuse, facile à cultiver dans les régions aux hivers très cléments, en plein soleil, dans un sol de préférence pauvre, même caillouteux, calcaire, sableux. Rustique jusqu’à environ -12°C (l’Agave havardiana affrontera des gelées de l’ordre de -23°C), en sol parfaitement drainé, dans les régions plus froides, elle sera cultivée dans de grands pots à remiser l’hiver.

De gauche à droite : Allée brodée d’Agave americana sous le couvert de palmier – Agave havardiana accompagné de cactus.

En climat doux où le gel ne sévit que très rarement, elle trouvera sa place dans une grande rocaille exotique, un talus sec, ou dans un massif sauvage surélevé.

L’Agave du Mexique est aussi utilisée pour fabriquer des boissons alcoolisées comme le mescal, et la Téquila faite avec des bourgeons floraux de l’A. tequilana ou encore, le sirop d’agave qui permet de remplacer le sucre en cuisine.

Main species and varieties

The most popular

Our favourites

Agave americana

An impressive perennial, highly valued for its monumental and remarkably graphic silhouette.

• Flowering time August, September
• Height at maturity 1,50 m

See the product sheet

Agave americana Variegata - American Agave

This variegated agave will find its place in a large rockery, or at the edge of a dry garden, where its monumental silhouette will stand out against a blue sky.

• Flowering time August, September
• Height at maturity 1,50 m

See the product sheet

Agave havardiana

It is the hardiest of the genus! Grow this perennial in the ground in almost all our regions, guaranteed exotic effect!

• Flowering time August, September
• Height at maturity 50 cm

See the product sheet

Agave victoriae reginae - Queen Victorias Agave

A small botanical species that does not exceed 40 cm in diameter. This agave is not the hardiest (down to -6°C in dry soil).

• Flowering time August, September
• Height at maturity 50 cm

See the product sheet

Agave Kichijokan

Not very hardy for the species, down to -12°C in dry soil. We love its grey-blue artichoke-like appearance.

• Flowering time August, September
• Height at maturity 40 cm

See the product sheet

Agave potatorum var. verschaffeltii

A small agave that will not exceed 1m in all directions as an adult. Very frost-sensitive, it makes an excellent plant for pot cultivation.

• Flowering time August, September
• Height at maturity 60 cm

See the product sheet

Young plantation

Where to Plant Agave

Agave is perfectly suited to dry, hot climates and poor soils. It is a rather tender perennial that will still withstand light frosts of short duration down to about -12°C (sometimes even lower for certain agaves) but only in open ground in the south of France, in poor, very well-drained soil. The drier the soil, the more frost-resistant it will be. Elsewhere, its hardiness is often put to the test.

Agave loves heat, sunshine, and arid soils, similar to “cactus soil.” It is very drought-resistant and can endure very high temperatures. In favoured regions, plant Agave in full sun in a well-sheltered spot, preferably on a well-sloped and well-drained site where water never stagnates.

While this beautiful succulent perennial proves to be quite hardy in dry soil, it does not tolerate excess moisture well, especially in winter, which would surely cause it to rot. It also struggles with winter rains and heavy, waterlogged soils in winter.

In mild climates, it copes very well with sea spray.

Provide it with a location that matches its ample growth: after a few years, Agave can become exuberant in open ground and for the larger varieties, reach surprising dimensions of up to 4-5 metres in diameter and the same in height!

Give it a clear space and keep spiny agaves away from pathways and young children!

In regions with harsh winters, it should be grown in a very large pot well sheltered on the terrace, to be stored indoors in winter or in a cold greenhouse, protected from severe frosts.

With its imposing and remarkably graphic stature, this succulent plant structures the exotic and wild decor of large dry rockeries, south-facing slopes, and large gravel beds, to which it adds volume.

In pots, it gives a wild exotic look to terraces and small urban gardens. Among a collection of cacti, it recreates a desert-inspired setting.

When to Plant Agaves

The planting of an agave is best done in spring from April to May or late summer, from August to September.

How to Plant an Agave

If your soil retains moisture, do not hesitate to plant your Agave on a slope that will be naturally drained. Choose a very sunny, warm, and well-sheltered spot. Pay attention to spacing to ensure its full development: space the plants at least 40 cm apart for smaller species and at least 3 metres for larger Agave species.

• Dig a deep hole (50 cm and even 80 cm for large agaves)
• Add large stones or gravel to a thickness of 20 cm at the bottom of the planting hole
• Mix river sand or pumice with half of the extracted soil
• Plant the agave without burying the collar too deeply and fill the hole with this same mixture
• Lightly compact the soil with your foot
•  Spread a layer of gravel or pebbles at the base of the plant to keep it dry and prevent rot; it will store the day’s heat to release it during the night
• Water generously, then suspend watering for 2 to 3 weeks after planting to help it settle in quickly
• After that, water very sparingly and only in very dry weather, allowing the substrate to dry out between waterings

Planting Agave in a Pot

The substrate must be very well-drained to avoid stagnant moisture and root rot. Place it in full sun, in a well-sheltered spot. Soil that is too clayey will be detrimental to the hardiness of this undemanding plant: improve drainage with gravel, clay balls, large pebbles, or a mix of stones…

• In a very large terracotta pot (better aeration) of at least 60 cm in diameter, spread a good layer of drainage (gravel or clay balls)
• Plant your agave in a mix of 50 % potting soil and 50 % clay balls or pumice
• Surround the base with a good layer of gravel or pebbles to prevent rot at the collar
• Water at planting, then once a month or even every 15 days during the hottest months. Always allow the soil to dry out between waterings.
• Apply a fertiliser low in nitrogen 3 to 4 times during the summer period
• As soon as the risk of frost has passed, gradually place the pot in the sun if it has been stored for winter to prevent the foliage from burning irreparably

The Agave filifera is adorned with long white filaments.

Maintenance and care

Once well established, the Agave requires no special care. It is easy to grow in regions where it does not freeze severely.

In the ground

Protect the base with a thick mineral mulch of gravel. It is a low water consumer as it has the ability to store water and therefore requires little watering.

In summer: water once every 15 days, not more. Once established in well-draining soil, it will become increasingly resistant to drought and will only need watering in case of prolonged dry spells.

Always allow the soil to dry completely between waterings. In winter, stop watering, as it relies on rainwater.

In winter, in very wet regions, you can protect the plant from winter rains with a clear plastic sheet raised above the plant.

Pruning is not necessary. Maintenance consists of a simple spring clean-up. In March, wearing thick gloves, clean the old foliage, using pruning shears or shears, and cut back any blackened, damaged, or wilted leaves.

In a pot

During summer, feed the plant with a low nitrogen liquid fertiliser “special for cacti” diluted in the watering water.

Bring the pot indoors before the first frosts, keeping it safe from the cold in a very bright, unheated room (between 0 and -5°C). Potted agaves are more sensitive to cold.

In winter, keep dry.

→ Learn more with Virginie’s tips on wintering an agave

Diseases and potential pests

Planted in well-draining soil and kept warm, the Agave shows a good resistance to diseases. It truly fears only two things: excess water and negative temperatures.

However, young shoots may suffer from attacks by mealybugs, identifiable by the cottony masses they leave on the leaves. They slow down growth and discolour the foliage. Remove the unwanted pests with a cotton pad soaked in 90°C alcohol, then treat with rapeseed oil sprays. Repeat two or three times at 15-day intervals.

If black spots appear on the leaves, it is likely due to excessive humidity: cut the leaves back to the base. Most Agaves are hardier than one might think. Cold itself is not really a problem, down to -7°C. They are more concerned about winter humidity. Excess water in the soil promotes the appearance of fungal diseases leading to root rot.

→ Read also: Agave Weevil: Effective Identification, Treatment, and Prevention.

The leaves of the Agave parryi ‘Huachucensis’ are beautifully bluish and edged with thorns.

Multiplication

If sowing is possible in February-March, it is very easy to multiply by taking young suckers at the same time. Most agaves naturally produce suckers around the rosette. It is very easy to detach them to multiply the plant from well-developed suckers (if they become too numerous, read about it Invasive agaves: practical guide to getting rid of them).

By dividing the suckers

• Using a spade, gently lift the sucker
• With pruning shears, separate the small agave from the mother plant
• Let the sucker dry for a few days in the sun
• Transplant it if it is sturdy enough or pot it on a bed of gravel in a mixture of turf and river sand
• Spread a layer of sand on the surface
• Place the pot in a sheltered spot
• Do not water for 15 days to allow small roots to form quickly
• Repot into a larger pot and plant in the ground the following spring

Associate

Agave, whether small or gigantic, is always an important focal point in a garden or in a pot on a terrace.

An undisputed star of dry and wild gardens scorched by the sun, it allows for the structuring of very minimalist exotic scenes, inspired by deserts.

It always brings character and grandeur to a decor.

A beautiful example of pairing in a rockery: Agave americana ‘Mediopicta Alba’, Agave montana, Yucca filamentosa ‘Color Guard’, Santolina chamaecyparissus, Berberis thunbergii ‘Admiration’, Lithodora diffusa ‘Heavenly Blue’, Saxifraga urbium, Linum perenne, Sedum reflexum ‘Angelina’, Sedum ‘Bertram Anderson’.

With their architectural habit, large agaves (A. americana) are perfectly suited to create a spectacular centre of interest in a bed of Mediterranean perennials such as Giant Fennel, Hesperaloe parviflora, the Canary Viper’s Bugloss (biennial) or even a Romneya coulteri or Tree Poppy of gigantic dimensions. Do be cautious of the shade cast by larger perennials, as it needs full sun!

In the ground, in a mild climate, the agave will find its place in a large rockery alongside equally undemanding plants such as the Barbary Fig (Opuntia ficus-indica) and other prickly pears, like Cylindropuntia imbricata and Opuntia humifosa, two hardy cacti or Aloe Vera.

For a purely exotic tableau, choose other plants that can withstand frosts down to -10°C; Crassulas, Cordylines or even Palms.

An example of exotic pairing: Agave americana, Agave americana ‘Variegata’, Aloe nobilis, Lantana camara ‘Lucky Red Flame’, Sedum ‘Herbsfreude’, Juniperus squamata ‘Blue Carpet’, Cordyline australis.

Its graphic silhouette will stand out in mineral scenes, punctuated by some grasses such as Miscanthus or Stipa gigantea.

Surround the base of the agaves with ground cover plants for dry soil such as Osteospermum or Cape daisies, dwarf wormwoods, toothworts, perennial purslane, thymes and sedums.

In a shrub bed, it pairs well with Fremontodendron californicum, a sarmentous shrub with sunny flowering, Australian Rosemary or a Céanothe thyrsiflorus repens.

→ Discover more beautiful pairing ideas with agave