Junipers Should Get More Consideration

Old junipers still work like new.

Too much of a good thing eventually gets old. That is how so many of the good junipers that were so popular half a century ago became so unpopular. They became too common, and many were planted into situations that they were not appropriate for. As they matured, many became overgrown or disfigured. Only recently have a few newly introduced modern cultivars restored the appeal of both new and traditional junipers to a generation that is less familiar with their former stigma.

Even though all junipers are evergreen and somewhat similar in regard to foliar texture and their lack of interesting bloom, they demonstrate considerable diversity. Some are low and sprawling ground covers. Others are dense low shrubbery. A few develop as small trees. Branch structure may be densely compact, gracefully arching, rigidly upright, or sculpturally irregular.

Some junipers have yellowish new growth that eventually turns to a more typical deep green. Others are bluish gray throughout. A few rare types are variegated. Almost all junipers have scale-like leaves (like those of cypress). A few have needle-like leaves.

‘Blue Arrow’ and more traditional ‘Skyrocket’ junipers are like short and plump Italian cypress with bluish or gray foliage. ‘Wichita Blue’ juniper is even shorter and plumper, with more sculptural branch structure. However, it is not nearly as irregular and sculptural as the old fashioned ‘Hollywood’ juniper. Modern ‘Gold Star’ and the older ‘Old Gold’ junipers are shrubby types that exhibit arching stems with gold tips.

‘Icee Blue’ is like an improved version of the classic ‘Blue Rug’ juniper, that matures as a shallow bluish ground cover. ‘Blueberry Delight’ juniper is one of the few junipers known for conspicuous fruit, with pretty powdery blue berries against grayish needle-like foliage on trailing stems. ‘Limeglow’ juniper gets a bit deeper, and exhibits chartreuse new growth that turns rich green.

Just because junipers can be shorn certainly does not mean that they should be! Shearing deprives junipers of their naturally appealing texture and form. Instead, junipers should be selectively pruned only where necessary to eliminate growth that is beginning to become obtrusive. Stems should be cut back deeply into the main stems from which they originate, in order to avoid leaving stubs or disfigured stems. Tree junipers like ‘Hollywood’ juniper, as well as overgrown shrubby junipers, can be pruned to expose bare trunks and stems. The gnarly stems and shredding bark can be as appealing as the foliage that obscures them.

Otherwise, once established, junipers do not need much attention or water, and are remarkably resilient. They only rarely get infested with spider mites or scale insects, or get damaged by disease. They only want good sun exposure.

Manzanita

Shrubby manzanitas develop sculptural stems with shiny cinnamon brown bark.

There are more than a hundred specie of Manzanita, Arctostaphylos spp., that range in size and form from creeping ground covers to small trees that can get almost twenty feet tall. (They are more commonly known by their cultivar names than by their specie names.) Arctostaphylos ‘Emerald Carpet’ is as the name implies a nice low groundcover for dry slopes. Arctostaphylos ‘Doctor Hurd’ is a shrubby small tree that is often pruned to expose strikingly sculptural trunks that are as smooth and rich brown as a chestnut.

Abundant trusses of tiny ‘urn’ shaped flowers bloom about now. Almost all are pale white. A few are pale pink. The subsequent red berries typically get eaten by birds before anyone else sees them. The evergreen foliage is quite dense. Individual leaves are rather small and disproportionately thick.

Manzanita should be planted while small, because larger plants are more susceptible to rot. New plants want to be watered to prevent desiccation until they disperse their roots. If planted in autumn, they get enough water from rain through winter (typically), so that they only want occasional watering through the following spring and summer. Once established, they do not want much water at all, and can be damaged by fertilizer. The happiest plants are satisfied with what they get from rain after they get established.

Curve Leaf Yucca

Curve leaf yucca can be variegated.

Some perennials are too easy to grow. Curve leaf yucca, Yucca recurvifolia (or Yucca gloriosa ‘Tristis’), is remarkably resilient. It migrates slowly but surely. If it becomes obtrusive, it is difficult to contain and remove. Removal of foliar rosettes above does nothing to slow the roots below. The roots merely produce new foliage. Of course that can be a distinct advantage for harsh conditions.

The striking foliar form resembles that of other species of Yucca, except that it reliably arches softly downward. Foliage is not as soft as it seems though. Each leaf terminates with a sharp spine. Sharp edges can cause wicked paper cuts. Foliar color is bluish gray. Although, variegated cultivars are increasingly popular. Old plants can develop trunks that slowly grow more than six feet tall.

Tall and elegant spikes of relatively small creamy white flowers stand grandly above the evergreen foliage in late spring or summer. Bloom is best with warm and sunny exposure, and lasts a long time. Viable seed is rare. Propagation by division of some of the many pups is simple though. Popular variegated cultivars exhibit more docile growth with fewer pups, but bloom less abundantly.

Coffeeberry

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Coffeeberry must be and ‘acquired’ taste. (Ick!)

Before the 49ers of the Gold Rush discovered that the seeds of the native coffeeberry, Rhamnus californica (or Frangula californica), make a nice uncaffeinated coffee substitute, the native American Indians were eating the fruit and using the leaves and bark herbally. The black berries supposedly make good jelly, but do not last long, and are too bitter while still red or greenish.

Before the birds get them, the quarter inch wide berries are somewhat colorful, but are not very abundant. The small clusters of tiny greenish yellow flower that bloom in spring are not much to look at either. The army green evergreen foliage is the main appeal. New stems are somewhat ruddy. Old stems and main trunks have smooth gray bark.

Large coffeeberry plants in the wild can get more than ten feet tall, with relatively open branch structure. Garden varieties stay smaller, with compact branch structure. ‘Eve Case’, which is probably the most popular variety, stays less than six feet tall, and is densely foliated. ‘Mound San Bruno’ is even more compact, with smaller leaves. ‘Seaview’ is a groundcover.

Santa Barbara Daisy

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Some of us know Santa Barbara daisy by the less appealing name of ‘fleabane’.

Santa Barbara was not exactly its first choice. Santa Barbara daisy, Erigeron karvinskianus, is not even native to California. It is actually from Central America. It just happens to do very well here, and can naturalize if conditions are right. It can be rather grungy through summer in the wild, but with a bit of watering, it can bloom nicely all year.

The thin stems can spread a few feet without getting more than a foot deep. If even shallower growth is preferred, older plants can be cut down or pulled up as they get replaced by their own offspring. The narrow leaves are quite tiny. The white or slightly pinkish flowers are not much bigger, less than half an inch wide, with prominent yellow centers.

Santa Barbara daisy is also known as Mexican fleabane, both because it is actually native to Mexico, and also because it is supposedly useful for repelling fleas. The problem with using it to repel fleas is that only its smoke is effective. There are probably other herbal alternatives that work just as well without being a fire hazard.

Butterfly Bush

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Garden varieties are less likely to naturalize than the straight species is.

Many plants are so easy to grow that they become invasive weeds. Butterfly bush, Buddleja davidii, has done exactly that in some regions, and is only controlled here by the arid climate. Yet, once established, it does not need much water at all, and can survive on rainfall in some spots. They only want good sun exposure.

Mature plants can get more than 15-feet tall and half as broad, with long arching limbs. Most garden varieties stay smaller, and some do not get much more than six feet tall. The evergreen foliage is sage green, grayish green or chartreuse. The paired leaves are about the size and shape of willow or eucalyptus leaves.

Conical trusses of densely packed tiny flowers that bloom in mid-summer can be various shades of blue, purple, red and pink, as well as dusty white. Some new varieties bloom soft orange or yellowish orange. The more compact and colorful modern varieties are not as fragrant as old classics are.

Summer Is Not For Planting

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New plants are less reliant on irrigation if installed at the beginning of the rainy season.

Autumn is the time for planting. Cooling weather slows plants down so that they do not mind disruption so much. Increasing rain (hopefully) keeps the soil evenly moist while roots slowly disperse. The combination of cooling weather, increasing rain and shorter days keeps plants well hydrated so they can slowly ease into spring.

Why is this important now? Well, it probably is not important. It merely demonstrates why this is not the best time for planting. Only a few warm season annuals and vegetables get planted this time of year. Seeds for certain autumn vegetables get sown now. Otherwise, more substantial plants should wait until autumn if possible.

Mid summer in some ways is the opposite of autumn. While the weather is warm, plants are too active to be bothered. Even minor disruption can be stressful. Soil moisture provided by irrigation is often too irregular and unreliable for dispersion of many new roots. There is less time to recover from stress during shorter nights.

Smaller plants and seeds survive summer planting better than larger plants do. Seeds need to disperse all new roots anyway, so they  will adapt to what they get. They certainly need regular watering, but are quite talented at putting their roots wherever the moisture goes. With a bit more time, smaller plants will do the same.

Larger plants have more difficulty with the planting process because they need to disperse so many more roots to get established. When they get planted, all their roots are initially confined to the volume of media (potting soil) that they were grown in. They are susceptible to whatever happens within  that limited volume.
For example, a small plant in a four inch wide pot is initially confined to less than sixty-four cubic inches of soil. It can double its soil volume to one hundred forty-four cubic inches by merely dispersing roots less than one inch laterally. A tree in a 24-inch wide box needs to disperse roots ten inches laterally to do the same!
It would seem that drought tolerant plants would be less susceptible to the stress of planting in summer.

However, they are more sensitive because they are so reliant on extensive root dispersion. Until they disperse their roots, they actually need to be watered as frequently as other plants do.

Agave filifera

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Foliage is better than bloom, and lasts longer.

For a tough perennial that is is grown for striking foliage, the small Agave filifera has a remarkably striking bloom as well. The one and a half inch long flowers are impressive pale green, and mixed with faded flowers. What makes them so compelling is that they are displayed on sculptural floral spikes that stand nearly six feet tall.

Unfortunately, each dense rosette of foliage is monocarpic, which means that it dies after bloom. Pups (sideshoots) sometimes develop as a main rosette deteriorates. If multiple pups develop and get crowded, they can be divided. Each rosette takes a few years to bloom, so should be around for quite a while.

The stiff evergreen leaves get about a foot or a foot and a half long, with unpleasantly sharp tips. Vigorous plants have white filaments that peel from the edges of the leaves. Like all agaves, Agave filifera, does not need much water once established. Unlike other agaves, it can tolerate a slight bit of shade.

Rockrose

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Rockrose is just beginning to bloom.

The first bloom is the best. At least it is purported to be. Many of us who are familiar with any cultivar of rockrose, Cistus, might disagree. Bloom begins in spring and continues through summer. The most profuse bloom can be anytime within that range. Some cultivars bloom sporadically but continually. Others bloom in more distinct phases. Cultivars that start later can bloom into autumn.

Bloom is white, pale pink, rich pink or purplish pink. Individual flowers have five petals and fuzzy centers. Flowers of some of the older cultivars have a prominent rusty red spot at the base of each petal. Smaller flowers are more profuse than larger flowers. The small evergreen leaves of most rockrose are somewhat grayish, with a matte finish. Foliage is aromatic when disturbed or warm.

Most rockrose are appreciated for their low and mounding form. If arranged in a row, they can grow into an artificial berm. Most get at least three times broader than tall. Few get taller than three feet. They all appreciate warm exposure. Once established they do not need much watering. Unfortunately, most rockrose do not live much longer than five years. Few survive more than ten years.

silver dollar gum

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There are actually a few different eucalypti known as silver dollar gum. The most familiar and largest is Eucalyptus polyanthemos. Mature trees that were popularly planted through the 1960s are about forty or fifty feet tall. Some stay smaller. A few that compete with taller trees are more than sixty feet tall. Trunks and limbs are somewhat sculptural, with fibrous bark.

Grayish foliage on limber stems forms a billowy and rounded canopy that blows softly in the breeze. Juvenile leaves are nearly circular, and more silvery gray than adult foliage is, like silver dollars. Ovate adult leaves are about three inches long and half as wide. Tiny flowers with prominent white stamens bloom amongst the adult foliage in spring and summer.

Smaller trees are often pruned aggressively or pollarded so that they continually produce the more desirable juvenile foliage without bloom. The problem with this technique is that it must be repeated every few years or even annually. Otherwise, vigorous secondary growth can get too heavy and break away.