Matthew Stevens: Agave copes well with hot temperatures, dry soil

In a previous column, I mentioned xeriscaping as a long-term solution to help gardeners better deal with drought conditions. Grouping plants according to water needs and incorporating more plants that can tolerate extremes may help gardeners make more efficient use of water while keeping their landscapes thriving.

One drought-loving plant that might catch some gardener’s eyes is the agave, also known as century plant or false aloe. Agave is a southwestern succulent plant that many assume has the same needs as a cactus, and it’s true, agave do quite well in hot temperatures and dry soils.

They will grow best in sandy, even rocky soils, and are a great fit for rock gardens and sunny spots where other plants just don’t seem to grow.

That is not to say agave has to always be bone dry. When grown in our climate, in fact, agave can actually tolerate a surprising amount of water during the growing season provided the soil has sufficient drainage. It would have to in order to grow here, because even with dry periods here and there, we get quite a bit more rain in spring, summer and fall, than where agave more commonly grows in the southeast.

What agave can’t stand is to be in wet soil during winter time. Wet soils in summer dry out much quicker than wet soils in winter, simply because of the air temperature and rate of transpiration for other nearby plants.

Two inches of rain from a July thunderstorm might be all but gone in a few days, but two inches of rain (or snow, or ice) in January stays in the soil for a long time. For plants that don’t like wet feet, that is a recipe for root rot.

So, if growing a plant like agave, make absolutely sure that you have excellent drainage in the spot where it is planted. Mounding soil up so that the plants are raised significantly will help ensure proper drainage, as will incorporating sand and perhaps even gravel into the area around the plant’s root system.

That caveat aside, agaves can be excellent additions to landscapes and gardeners should consider using them if they can provide the appropriate conditions. With a wide diversity of sizes, colors, and leaf shapes, one could even fit several agaves into the right garden. Consider it as an alternative to yucca or prickly pear cactus (assuming you can get rid of either one), or a companion plant to summer flowering plants like lantana and salvia that prefer hot, dry locations.

Agave are called century plants because of how they bloom. The plant doesn’t actually take a full century, but it may take 30 years or so for an individual plant to flower. When it does, it sends a tall flower stalk high into the air, 10-20 feet or more.

The individual flowers on the stalk are yellow to yellow-green, and are fairly long-lasting. Agave are monocarpic, meaning they produce flower and seed only once at the end of its life cycle, and then die after flowering.

Luckily, agave plants produce many basal offsets, so if the mother plant dies after blooming, there are more likely multiple daughter plants that growing at her base and ready to carry on her legacy in the garden.