This posting was first published in the HPSO Bulletin Spring 2010 and is here revised
South Africa is one of the most botanically rich regions of the world. Within its boundaries is the Cape Floristic Region (with 0.08% of the world’s land and 3% of all plant species), containing some 8,700 species, two-thirds of which are endemic, existing nowhere else in the world. It is one of only six such regions in the world. By comparison, the Boreal Floristic Region includes all of North America, Europe, and the northern portions of Asia and Africa, and is thus considerably larger. Each region has a distinctive “suite” of plants with particular families that are endemic to them. One would feel a familiarity when exploring anywhere within one’s own region. Outside it, you might feel the world was populated with the alien plants of other star systems. For example, forests are not to be found in the Cape (though nonnative species have been introduced and have spread); instead, these areas are characterized by heaths, proteas, and restios. Included in the region are 2,700 species of bulbs in 15 different families. These include gladioli, freesias, amaryllis, agapanthus, and many others, most of which would be unrecognizable to the average temperate area gardener. One such genus of bulbs is Eucomis.
There are 11 species of Eucomis. One, E. zambesiaca, comes from the mountains of Malawi, one, E. regia, from the summer-dry western Cape; while the others, including E. comosa, its varieties, and E. bicolor, come from the eastern portion of South Africa, where soils are relatively poor and they get summer rains. These are not, then, tolerant of summer drought, so will require irrigation here. They do well in the sun but don’t require full sun; a few hours a day should be plenty. These are quite prone to wilting in hot afternoon sun, especially when grown in pots. Give them well-drained soil for our wet winters, though they do seem quite tolerant of it in my experience.
As you might expect, the species look very similar one to another, varying mostly in size and color. Some species have purple-speckled foliage, so the fact that there are several purple-foliage varieties like E. comosa ‘Sparkling Burgundy’ is not a surprise. This one emerges with deeply channeled strappy, almost succulent, foliage in a rosette, dark purple, until the flower stem begins to emerge in late July – August when green begins to show through. The leaves are quite sturdy. Do remember that these aren’t tropical, however, and that they are hardy to zone 6, so should do well anywhere in the Willamette Valley as long as they are in the ground.
The flowering stem emerges purplish and erect. As it extends, the tightly held flower buds and a tiny tuft of leafy bracts at the top are reminiscent of a small narrow pineapple, hence its common name, “pineapple lily.” Several other species, like the aforementioned E. zambesiaca and E. bicolor with their more prominent topknots, look even more “pineapplish.” By late summer, my E. comosa ‘Sparkling Burgundy’ planted in less than full sun often fall over, both flower stems and droopy foliage, though the tissues still feel turgid. Too much irrigation or too rich of soil producing overly lush weak growth??? I’ve grown these in several different locations, even with pretty minimal supplemental water. None of the other eucomis have done this for me.
The flowers are arranged in a raceme, crowded, but each standing out as distinct individuals. On E. comosa ‘Sparkling Burgundy’, the flowers appear to be fleshy and translucent, like opalescent glass, each petal with a purple edge. Others may have pure white flowers or more evenly pink. Because they are members of the hyacinth family, you might expect them to be fragrant, but be careful — some are quite malodorous attracting flies as pollinators, but in general they are nothing too odious. They are long lasting, over a month, and form an attractive fruit which is ornamental as well.
These have proven to be tough plants that readily increase, but not to the point of being a problem. The main flowering bulb, a corm actually, can be quite large: three to four inches in diameter on the E. comosa varieties. They form neither bud scales, like lilies, nor little offsets or bulbs, like daffodils, or corms, like cyclamen. Their bulb shares more of the appearance of the vegetable kohlrabi. Kohlrabi has an aboveground rounded swollen stem with leaves that spring from it. When dividing your Eucomis, take a sharp knife and cut down through the bulb where there is a separate shoot rising. I have done this in the winter and spring and have yet to lose a single start. I plant these in small pots in potting mix rather than directly in the soil, where soil fungi may be a factor. There seems to be no reason to dust the cut surfaces with fungicide.
Corms may often look like ‘true’ bulbs, but they are not. Some, like those of Eucomis, begin from a longer section of stem with one or more nodes and take on a more irregular shape as they age, growing and adding nodes to their bulk that will form multiple crowded flowering stems and sets of leaves. They are solid starchy structures when cut into not the layered structures of true bulbs. They don’t produce scales from which they can be increased. Instead, they can be cut into pieces that will grow on successfully if they include a bud or ‘eye’. While other corms will actually form a ‘stack’ of young corms on top of the older ones…think Crocosmia.
If you are interested in the growth and flowering of bulbs check out the pertinent sections of my posting on the growth of monocots, specifically the one headed, ‘Meristematic Tissue and Flowering’.
I’ve planted a few E. comosa ‘Sparkling Burgundy’ at Columbia Circle and in the South Waterfront Garden. There are some Eucomis zambesiaca. with their one-foot-tall white-flowered stems at Columbia Circle as well on the south end. E. zambesiaca produces viable seed here, and near the bed’s surrounding bench, next to the sprinklers, it seems wet enough that some have germinated and have done well. I have seen no seedlings anywhere else, I presume because our summers are too dry.
One species, E. pole-evansii, can grow to 4′ -5′ tall and has much broader leaves, imparting a bromeliad look (there’s that pineapple thing again) and an overall appearance that is even more tropical. Opinion varies but these are said to be hardy down to zn 8 or 7.
The eucomis have been hardy for me in my zn 8a garden and an easy-to-grow choice for anyone wanting to add lushness to their summer gardens. They make a beautiful centerpiece on the deck table, the smaller ones anyway. The inflorescence of E. bicolor is odd and intricate and has alternated on my table with Arisaema ringens and could share time with an orchid. They fit in perfectly in gardens going for a tropical look.
Last winter, ’13/’14, was a mini-disaster for my Eucomis, at least the one’s I had in pots. At some point, grouped under a tarp, under the roof overhang, they got too cold for too long freezing the pots and, as I later found, causing all of them to go to mush. Those in the ground were fine. Dead was Eucomis pole-evansi, E. ‘Can Can’, E. bicolor, some starts of E. ‘Sparkling Beauty’ and E. ‘Freckles’. Pots because their surfaces are all exposed to the air are subject to freezing quicker and deeper. Obviously the water in Eucomis bulbs have little to no ‘anti-freeze’ compounds in them to stave off freezing so that once the water crystalizes the cell structure is shattered, pierced, or otherwise macerated by the icy shards. I’m still growing these having replaced my E. pole-evansi and E. Freckles this last summer.