A Gardening Journal

Foxtail Lilies, Below Ground & Above

One of the counter-intuitive delights of plants—so much of whose growth is, necessarily, above-ground—is that what’s below ground is sometimes startlingly visual. Roots of yellow root are—you guessed it—yellow. Chrome yellow. Feeder roots of lotus form a starburst of white filaments, each with a pink tip.

 

But here's the rub: Such shows are on display only when the plants are bare-root. Keep that lotus out of water for more than minutes, and it will begin to wilt. For the day? It could die outright.

 

Happily, a favored few plants are marketed as dormant tubers, rhizomes, corms, or bulbs that tolerate being out of the ground and fully visible for weeks or even months. And a few of those normally-hidden structures are stunners. Take so-called foxtail lilies, named for their vulpine flower spikes in spring. This is a grabbed-from-the net picture of one of the hybrid foxtails I’ve planted this fall, Eremurus x isabellinus 'Cleopatra'.

 

eremurus x isabellinus cleopatra 640

 

Flower spikes of Cleopatra can be four feet tall, and are bushy-tailed, indeed. Below, another grabbed-from-the-net shot, this time of Eremurus robustus. Its spikes can soar eight feet and higher!

 

Eremurus robustus from the net 640

 

No matter which of the scores of Eremurus species and hybrids you choose, the roots you'll plant look more or less like the one below: Spidery, fleshy tuberous legs ring a central core that usually has a single just-waiting-to-erupt growth point.

 

Eremurus hybrids fingers close up 120717 640

 

The legs are always described as being fragile; while you could snap one in two, that isn't normally the danger. (You want your foxtails to establish and thrive, so you’re just the sort who will handle them respectfully.) Rather, an entire leg can simply detach from the central core. In and of itself, this isn't a problem, either: There are other legs, and more will form. But still, it’s the legs that absorb the moisture and nutrients that, come spring, power each plant's shockingly vigorous eruption of leaves and flower spike.

 

There's usually just a single spike per core, but cores divide when conditions are favorable. A happy Eremurus multiplies to a multi-stemmed colony. The quicker and more fully Eremurus plants can establish, the sooner their floral display wlll go toe-to-toe with the ones in the pictures above. More literal legs, then, means that the plant's performance will have more "legs" all the sooner.

 

Spread out in the sun while awaiting their planting, this group of Cleopatra tubers resembled crabs. (Geek alert: Two collective nouns are appropriate for a group of crabs. My tubers, then, could be described as resembling a cast of crabs or, more grandly, a consortium of them.)

 

Eremurus hybrids tubers on the sideboard 120717 640

 

The sort-of-fragility of the tubers is, in reality, a minor concern. The major one is foxtail lilies’ requirement for excellent drainage at all times—and especially during the cold months, when they are dormant. The easiest solution is to never plant Eremurus on level ground; always plant in a bed that is mounded so that surface water runs quickly away. 

 

No wonder I’ve hesitated with Eremurus for many years: My garden’s rich and dead-flat soil would likely have been fatal. Plus, Eremurus are typically hardy only to climate zone 5, so might not have survived being planted in one of my well-draining but entirely-above-ground troughs, either. 

 

This past summer, I inadvertently created spots for Eremurus that might be ideal: raised beds of rich soil—but for towers of high-climbing warm-weather vines, not fussy perennial tubers. The vines weren't planted until late May or even June, and were dead by the first frosts of November. The rest of the year, the beds would be empty. What a waste!

 

Eremurus hybrids galvanized raised bed west down the alley 120717 640

 

Helpfully, Eremurus foliage begins to fade even as the flower spikes themselves are peaking in spring, so the lilies would be fully dormant by late June. At that time, the annual vines would still be scrawny youngsters barely two feet tall.

 

So I planted Eremurus towards the middle of the raised beds—around the bed’s center pole—where the tubers are the most protected from the quick cycle of freezes and thaws that will affect the beds’ perimeters in winter. By the time the annual vine planted by each of the three perimeter poles will have climbed high enough to cast shade on the center of the bed—mid-July—the Eremurus there will have become completely dormant.  

 

Eremurus hybrids galvanized raised bed close up 120717 640

 

Although the vines and the foxtails both demand full sun, their different seasons of growth mean that each will bask at no inconvenience to the other.

 

That the beds also ensure that the foxtails enjoy fantastic drainage year-round was an unexpected bonus. I didn't create the raised beds with drainage in mind at all: The annual vines grow during the dog days of July through September, when drought is the challenge, not drainage. Raised beds were just the easy way to amass sufficient rich, moisture-retentive soil in three full-sun locations down the garden's central alley of grass, while keeping anything planted in them safe from the lawn mowers.

 

But drainage can never be too good for foxtails, so merely raising the level of soil above the level of the surrounding grass wasn’t enough. The soil is gently mounded, too, in hopes that some of the water from heavy rains will slide right off the beds’ sides before it has the chance to soak in. 

 

Plus, I've used mulch that's inert, not organic: stones, not bark. While both still allow water to pass down through, the stones don't retain it.

 

Eremurus hybrid bed mulched with stone 121517 B 640

 

One final step: The same cap of heavy cardboard that I create each fall to enhance survival of another genus of perennials that also demand great winter drainage: Kniphofia.

 

Eremurus hybrid bed cardboard cap 121517 B 640

 

The cardboard prevents winter precipitation from reaching the soil beneath, while the thick layer of mulch beneath—those stones—still allows air circulation.

 

I won't rush to remove the cardboard in the spring. Eremurus can be eager to break dormancy, and the new growth can be caught by late frosts. Keeping the cardboard cap in place a couple of weeks longer—say, until mid-May—keeps the Eremurus in the soil beneath it in the shade and, one hopes, still cool and drowsy. Uncovering when the sun and temperatures have both become consistently warm will bring on a performance that is frost-free and, so, full-throttle.

 

 

I'll profile Eremurus in late Spring of 2018, when I hope that the three cultivars I planted this fall—Cleopatra, Romance, and Orange Marmalade—will all be in full flower. If my efforts at providing well-drained locations are successful, I'll then attempt the giant of the genus, Eremurus robustus, in the biggest-of-all raised bed at the distant end of the reflecting pool. This is more than two hundred feet from the house, from which flower spikes eight to ten feet tall would still be prominent.

 

 
 
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