Irises: Carefree Backyard Orchids


flag iris (Iris germanica)

flag iris (Iris germanica)

The time is now for irises, whether you prefer classic bearded fleur-de-lis irises or native, Pacific Coast irises. Last week I had the privilege to visit two horticultural venues that featured irises among their many botanical gems. One was the Theodore Payne Foundation in Sun Valley and the other was the backyard slope of Paul Weinberger in Woodland Hills.
Iris comes from the Greek word for rainbow and you can find them in any color, but especially in purples, pinks and yellows.
Of course, a garden does not need to feature irises. Irises simply steal the show and do not require top billing. Irises have earned the appellation of backyard orchids, an anomaly of sorts since backyard implies easy to care for, and orchids are commonly thought of as finicky plants.
Yet irises, although their beauty rivals that of orchids, are probably the easiest plants to maintain since all you really have to do is look at them. They do not demand summer irrigation yet, at least where bearded irises are concerned, they are not bothered by it either. You can plant bearded irises in a drought-tolerant or a more thirsty English garden yet be rewarded with the same voluptuous flowers in each.
The popular tall bearded irises are known, by their Latin name, as Iris germanica, a misnomer since the habitat of these hybrid irises is not Germany, but rather the dry open fields and hill country of Mediterranean lands from Italy to Morocco. So much hybridization has occurred, however, that no one can accurately trace the origin of these most recognizable irises. Although irises are not typically fragrant, you will find fragrance in some of them, and a plethora of iris types, including scented ones, are easy enough to find among Internet vendors. Incidentally, the perfume of bearded iris rhizomes (their fleshy semi-underground bulblike stems), referred to as orris root, is legendary and expensive. Orris root requires a five-year drying and processing period before it can be made into perfume.
Moreover, one ton of iris rhizomes produces less than five pounds of orris root essential oil, whose unique fragrance, both woodsy and flowery at once, is worth the effort its lengthy manufacture requires.
Weinberger has spent 15 years transforming his backyard slope in Woodland Hills into a garden. Carpeted with geraniums, coral bells and succulents, he has done a wonderful job of eliminating any possibility of erosion. Coming up here and there are several breathtaking bearded irises.
Pacific Coast irises (Iris douglasiana), although native to California, are more temperamental than the common fleur-de-lis or bearded irises. Many varieties are on sale at the Theodore Payne Foundation Native Plant Nursery. They prefer dry soil during summer and are recommended choices for planting under pines and oaks.
Visiting the Theodore Payne Foundation in Sun Valley is always full of surprises, especially in spring when so many California natives are in bloom. At the entrance to the nursery is a ground cover primrose I had never seen before. Its silky yellow flowers stop you in your tracks. It will remind you of the weedy Hooker’s evening primrose (Oenothera elata ‘Hookeri’), which bears similar flowers atop 3-foot stalks.
Speaking of yellow-flowered ground covers, there is a fascinating dwarf buckwheat (Eriogonum umbellatum ‘Shasta sulfur’) on display that you will want to take home. I had never noticed anything special about Ceanothus bark until studying the angular, 12-foot greenbark ceanothus (Ceanothus spinosus) growing outside the Theodore Payne offices and bookstore. This would make a fine tree for a small backyard. If you can resist watering it, it may live for half a century or longer.
Q. I hope you can advise us regarding our lemon tree, which I believe to be more than 25 years old. It’s been doing great, especially after we removed a few larger trees next to it that had died and had shaded it before from the sun. But now, the lemons have recently been showing lots of bumps. Peels are thicker and bumpier than before. I don’t know if this is due to all the rain we had or to a calcium deficiency and would appreciate your advice. We fertilize it regularly with citrus food.
– Rich Hollow,
A. Examine your tree to see where the branches producing your bumpy fruit originate. In all likelihood, they originate in wood coming from the base of your tree.
Fruit trees consist of a named scion variety, such as ‘Meyer’ or ‘Eureka’ lemon (Citrus limon), grafted onto a rootstock. In the case of lemon trees, the rootstock is an entirely different species, such as Volkamer (Citrus volkameriana) or rough lemon (Citrus jambhiri). These rootstocks are used because of the virus resistance they impart to the scion variety.
The fruit of both rootstock types is bumpy. In older lemon or other citrus trees of declining vigor, it often happens that a sucker from the rootstock grows into a vigorous trunk of its own with fruit-bearing branches.
You will have to cut this unwanted growth back to the original trunk before you can hope to see normal lemons which, as long as some of the original scion remains, will now have the ability to develop, absent competition from rootstock growth. Heavy rain has no doubt given a push to the wayward growth of your tree but calcium, while its lack causes peel lesions in apples, for example, is not a factor in growth of bumpy citrus peels.
Q. My orange tree fruit is so bitter it is inedible. I am close to cutting down the tree. Is there any way to make the tree produce edible oranges?
– Bill Rice,
A. There are two possible explanations for your bitter oranges. If the tree produced sweet oranges at one time, then your rootstock (see above) has taken over the tree and the fruit produced comes from it. Alternatively, if the oranges have always been bitter, you have a seedling or ungrafted tree. If you take a seed from a supermarket orange and plant it, the fruit from the resulting tree is likely to be bitter.
Tip of the week
Paul Weinberger’s large clumps of coral bells (Heuchera species) are several years old. This is highly unusual since coral bells seldom survive more than two years in the garden. Most coral bells die from soil that is too moist and leads to root rot. The health of Weinberger’s plants may be attributed to his sloping terrain, topography that ensures excellent drainage and dry roots.

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