Water Hoarding

Posted by & filed under Formal Gardens, Perennials.

Aloe saponaria flowersThanks to hot temperatures and infrequent rains, the gardeners have really had to work hard to keep the plants watered and healthy these last few weeks.  Given our adversarial relationship, normally I would laugh at their misfortune. Instead, since my thirsty roots benefit as much as their targeted plants, I am thankful for all their efforts. Graciousness when your opponent does something good seems to be difficult for many people, but I feel it is important to practice it when I can.

Some parts of the Garden have in-ground irrigation and regular watering provides the precious liquid to happy plants.  But other areas, including many containers, require a gardener to drag a hose and sprinkler or watering wand.  Of course plants all have different needs.  Large trees and shrubs can sink roots deep to hidden reserves in the soil. Many perennials need water a little more often.  Spiral Spurge (Euphorbia spirailis cristata) Rapidly growing and sharing bright flowers in their short life span, most annuals need a lot of moisture to ensure that vigorous growth everyone loves. Of course some plants need very little irrigation.  These water hoarders are known as succulents.

Succulents are plants that store water in their leaves, stems or roots.  A good example is a cactus, but it is by no means the only succulent in the plant kingdom.  We have succulents located in various spots around the Garden but three main areas come to mind right away.  The first is the green roof on the boat ticket hut hosts many succulents, especially sedums.  The desert garden in the WOW children’s garden has succulents of all sorts including many forms of cactus, agBear's Paw (Cotyledon ladismithiensis)ave and yucca.  The third display on the education patio near the hummingbird garden features African succulents.

The African Succulent display consists of several large and many small containers of succulents from South Africa and Madagascar.  You will not find any cactus in these pots, since cactus are only from the Americas.  Instead there is a rich variety of Euphorbia, Senecio, Haworthia, Cotyledon (right) and many others.  For those of us used to plants from a temperate, moist climate, these can seem a little strange at first. However, spend a few minutes with these plants and you will really appreciate their beauty and their abilities.

Zebra Plant (Haworthia fasciata)Only a few plants are flowering right now.  A large aloe fills a pot near the back of the display. Tubular coral-colorMilk Barrel (Euphorbia cereiformis)ed flowers explode from the top of tall gray stems.  Nearby in one of the larger pots are several varieties of Haworthia. The one commonly called fairy washboard sports a wiry stem atop which several tiny striped urn-shaped flowers bloom.  The plant gets its name from the horizontal ridges that grow along the thick triangular leaves forming a rosette at the ground. Another Haworthia is called the zebra plant (above) because the ridges are white against the darker green leaves.

Euphorbia is one of the most diverse genus in the display.  The milk barrel plant (right) may look like a cactus at first glance but it has a milky sap instead of the clear sap of a cactus.  Cactus also has clusters of spines coming from one point called an aerole while the milk barrel spines are modified parts of a leaf (the stipule) and have no aerole.  While other Euphorbias also look like cactus (Spiral Spurge, for example), some look have completely different looks like the contorted mass of the Frilled Fan or the fleshy leaves dotting the trailing stems of Euphorbia franoisii.  

Silver Coral (Senecio scaposus)The leaves of some of the succulents are real hoarders. Blue chalk sticks and silver coral (left), both in the genus Senecio, have fleshy leaves full of stored water.  Since they have almost no stem at all these little plants look like fingers reaching up out of the gravel.  It is hard to believe these plants are related to asters and ragworts.  Bear’s Paw is another plant where the leaves are so swollen that they look like the puffy appendages of a bloated bear.

Finally there are just some Club Foot (Pachypodium namaquanum)odd looking plants.  Club Foot (right) is a single stemmed plant with spikes along the stem.  A small tuft of leaves sprouts from the top, giving it an almost comical look.  In this display, the Club Foot is less than a foot tall, but they can reach 12 feet or more by the time they mature.  Its Pachypodium cousin (below) is almost completely different in form.  Again it has a single stem, but it is very flat, looking almost like a cow patty.  It rarely grows taller than a few inches and produces a few sporadic leaves across the surface.  Right now yellow flowers are blooming on the plant, helping prove that it is not an escapee from the cow Pachypodium brevicaulepasture.

Hopefully, we will get some rain soon and the gardeners will stop dragging so many hoses.  Until then, we will just have to admire the water conservation skills of these succulents.