Sudden Mediterranean Plant Collapse Disorder

Which is why I’m ecstatic that this one cutting of Coronilla valentina subsp. glauca ‘Variegata’ has rooted. Emergency cuttings were taken just before it collapsed in a dessicated heap a couple summers ago, a sad day. I was truly smitten with this plant. I’d never seen one before and haven’t since, so it’s fairly rare. But at first glance, some plants just seem to make perfect sense to me. (Some good plants, like cannas, takes years to warm up to.) The scarce information I could find came from, of course, English garden writers (Val Bourne writing for The Telegraph.) A fragrant, evergreen, winter-blooming shrub in the pea family with bright yellow flowers and rue-like foliage that has an especially shimmering quality in the variegated form. ‘Citrina’ has paler yellow flowers.

Unfortunately, the little cutting appears to have reverted to the non-variegated, so we can drop the ‘Variegata.’ The original plant came home from a road trip up the West Coast, purchased from the Portland, Oregon nursery Cistus several years ago, and had reached a lanky 5 feet before its sudden death. In late February, I was sure new growth on the cutting showed definite signs of variegation, which can just be made out in the photo, or so I deceived myself at the time.

But wishing does not make it so, and the variegation did not come through. Photo taken in April.

That fateful day in August I knew the coronilla’s collapse was imminent and just managed to get some decent cutting material before its untimely end.
I’ve experienced this late summer plant collapse disorder before. Leaves lose their luster, look water-stressed, so you instinctively pour on the water, which hastens an even swifter death, stimulating some nasty soil pathogens running amok in the warm soil of late summer. And by the time the plant looks obviously stressed, it’s too late to do anything anyway. Other victims have been cistus, coprosma, olearias, prostrantherum. Soil too enriched? Too clayey? Too much water? The latter theory seems to be the conventional wisdom on this little-discussed subject, but my garden is, if anything, kept too dry. From the Cistus Nursery description: “Quite summer drought tolerant in dappled shade to bright sun. Lean conditions create more compactness.” Mine was a lanky 5-footer, so the soil may have been too rich. It’s also true that these mediterraneans are generally considered to be short-lived, but I never did see this young coronilla flower.

*From Mediterranean Gardening: A Waterwise Approach, by Heidi Gildemeister: “Air circulation around or within plants during summer heat is vital to Mediterranean vegetation.” Dense planting is a continual weakness of mine, but I try to be vigilant. Just last week I did a major thinning of the front gravel garden.
Leucadendrons and dwarf olives still encroach on Agave ‘Mr. Ripple,’ but I’m assuming he’s tough enough to take a little crowding.

Spring’s irrational exuberance is no time for morbid concerns. And, in any case, it looks like I’ll get another chance with this beautiful shrub — always keeping a steady supply of cuttings in reserve.