July 4, 2014
Yucca, photos by Steve Chandler
By Steve Chandler
When summer starts to push and most plants need a drink about every day, gardeners start to realize how hardy yuccas can be. Like most succulents, yuccas store water in their roots, trunks, or leaves, so they’re at home when it’s hot and dry. Fortunately, there are lots of yuccas that can thrive in our hot and humid conditions!
Gardeners may turn to yuccas when they’re looking for a plant that needs little attention, offers an alternative vertical shape to our usual floral array of leaves on stems, or promises to deter someone from a shortcut across the property. Many varieties offer color and appeal to those drawn to a hardy xeric (dry) look. Yuccas can be located in full sun, as about the only sure thing for that corner of the yard that’s too far from the water hose to get much care, or they can be integrated among other plants where you’re looking for something for visual contrast.
Yuccas may grow close to the ground, like our native Yucca filamentosa which usually only gets a couple of feet tall. Its green leaves will unravel white threads along the edges and taper to a spine that’s not so sharp as to make one avoid this plant. For color, look for Y. filamentosa ‘Color Guard’ with a yellow vein down the middle of each leaf that’s a real eye-catcher. The yellow may turn a hint of red in colder weather to add more show. Y. filamentosa usually blooms in early summer sending up a stalk about six feet high that bursts into white flowers to attract bees and birds for a couple of weeks.
If you want more height from a yucca, try Y. elephatipes. It can reach twenty five feet at maturity, often raising several trunks off a large base with leaves that die as they progress from the end of the trunk. The large base of Y. elephantipes is also visually interesting, reminding some of an elephant’s foot. There is little need to mulch the base with pine straw or tree bark as yucca will probably fair better without trapping moisture around the base. Its spines are not too sharp and Y. elephantipes hybrids offer leaves with a center or margin of yellow or silver to contrast with green.
Our most common yucca, the easiest to grow, is Y. aloifolia. It is the one most often called “Spanish bayonet” (although lots of yucca species are referred to as Spanish bayonet or Spanish dagger). It get that name because the sharp spines at the ends of their leaves will stab you if you walk into them and the edges of the leaves have serrations that may cut you if you’re not careful. For a plant that can easily reach seven to ten feet high and has a tendency to tip over and root where it falls, it can become a clump of points to watch out for. That said, Y. aloifolia makes a good accompaniment to a fence where you don’t want people to trespass, like around a dangerous culvert, a property line, or maybe even the median of a road. If Y. aloifolio is planted close to a sidewalk where pedestrians pass or kids play, you may end up trimming off the spines or periodically cutting down the whole plant at its base to keep the innocent from being poked. Unless you dig up its roots, the plant will probably grow back from the base – plus the pieces you cut off are easy to root somewhere else.
If you like the look of yucca, but worry about being poked, Y. recurvifola may be the right choice. It is a soft-leafed yucca without a discouraging spine and still gives a xeric appearance without much risk when you’re tidying it up or weeding underneath. It has a graceful look and blooms readily in our local gardens. Another good choice is Y. gloriosa ‘Variegata’, it comes in a yellow variegated variety and stays closer to the ground.
If you want to try a tree-form yucca that features more trunk than top, Y. rostrata ‘Shaphire skies’ is popular with its silver-blue shade of leaves on a solid trunk. It reaches four to six feet in height with a six to twelve inch trunk diameter. Most of the tree-forms are slow growers, taking several seasons to leave the ground. One that is recommended by Western growers as a possibility for our humid area is Y. treculenea. Its leaves can reach lengths of four feet and its trunk to fifteen feet high and two feet around. It’s an odd sight for our area and only a few are growing in xeric gardens here.
Steve Chandler is a Master Gardener volunteer with the Leon County Cooperative Extension Service and a member of the Leon County/UF IFAS Extension Urban Forestry/Horticulture Newspaper Column Working Group. For more information about gardening in our area, visit the UF/ IFAS Leon County Extension website at http://leon.ifas.ufl.edu. For gardening questions, email us at Ask-A-Mastergardener@leoncountyfl.gov