Watering Water Wise Plants

Excessive watering rots drought tolerant yarrow.

Native plants like coast live oak, valley oak, toyon, flannel bush, Western redbud and California lilac (ceanothus) are among the most resilient of plants as the weather gets dry and warm after spring. So are plants from similar climates, like bottlebrush, oleander, rockrose, grevillea, acacia and eucalyptus. They survive dry summers by dispersing their roots deeply into soil that does not get as desiccated as surface soil naturally does (without irrigation).

Ironically, these most resilient plants can also be difficult to work with while they are young. Because they rely on extensive root dispersion for survival, new plants that have not yet dispersed their roots can not survive long without regular watering. They only become tolerant to drought as their roots disperse into deeper soil.

However, because they are adapted to arid conditions, they do not like to be too damp for too long. Roots soon rot in soil that does not drain adequately between watering. They therefore need to be watered frequently, but not too frequently. Yes, that is as confusing as it sounds.

To make it even more confusing, these plants will need less watering as they mature and disperse their roots. Bottlebrush, oleander, contoneaster, hop bush, firethorn, grevillea and juniper can certainly tolerate more water than they really need; but wasting water is contrary to selecting drought tolerant plants to conserve water. Manzanita, coyote brush, rockrose, flannel bush and redbud may actually succumb to rot if watered too much. Even perennials like Pacific coast iris and yarrow can have problems.

Pine, oak, acacia and especially eucalyptus disperse their roots as soon as they can, so do not want to be confined in containers. It is therefore best to plant smaller young specimens than larger ones. #5 (5 gallon) eucalypti get established in the garden more efficiently than larger but more expensive #15 (15 gallon) trees. If #1 trees were available, they would be even better.

Tanoak

Tanoak is rare within refined landscapes.

Its plump and inch-long acorns are misleading. Tanoak, Notholithocarpus densiflorus, is not actually an oak. Otherwise, it would be a species of Quercus. Regardless, its wood is potentially as practical for furniture and flooring as wood of other oaks. It also works very well as firewood. Historically, tanoak bark was useful for tanning leather, hence its name.

Although native and somewhat common in some coastal forests, tanoak is almost never a choice for intentional planting. Those that inhabit home gardens likely either grew from acorns, or were there prior to development of the landscapes. Young trees can grow fast to more than forty feet tall, typically with conical form. Mature trees might get twice as tall.

Tall trunks of tanoak are elegantly upright, and eventually develop lofty branch structure. Their gray or brownish bark is handsomely furrowed. The somewhat leathery evergreen foliage produces potentially objectionable tomentum. The dentate leaves are two to four inches long. Sadly, tanoak is very susceptible to Sudden Oak Death Syndrome (SODS).

Six on Saturday: Politely Naturalized Exotics +1

Exotic plant species that appreciate endemic climates and soils seem like they should be the next best options to native plant species. A few unfortunately naturalize aggressively enough to displace native plants species, and interfere with the natural ecosystem. A few can not naturalize without their preferred pollinators that did not come with them from their origin. Some have potential to naturalize, but either refrain, or are civil about doing so. Some that are invasive within landscapes are not as invasive in the wild, particularly if they need more water than they get from local weather. I occasionally find exotic plant species, including a few that I am surprised to find.

1. Sticky monkey flower is the ‘+1’. It is the only one of these six that is native rather than exotic. Its odd name leaves one pondering how a monkey is involved and why it is sticky.

2. Mock orange seems to be naturalized, but contrary to common belief, may actually be native. A single flowered variety and a double flowered variety may be different species.

3. Jupiter’s beard is most certainly exotic and naturalized, but does not seem to be polite about it. It can get quite invasive. However, it does not get far from irrigated landscapes.

4. Iris remains a mystery to me. I grew this same seemingly simple species while in high school, but have never identified it. It naturalizes, but only where it gets sufficient water.

5. Spanish lavender is obviously not native since it is from, well, Spain. It can naturalize, but is not aggressive about it. The honeybee is much more aggressively naturalized here.

6. Crinum, like the Iris, is unidentified. I am not even sure if it is a Crinum. It grows wild with sticky monkey flower, in sandy soil that gets dusty, dry and warm through summer.

This is the link for Six on Saturday, for anyone else who would like to participate: https://thepropagatorblog.wordpress.com/2017/09/18/six-on-saturday-a-participant-guide/

Flannel Bush

Abundant golden blooms are really spectacular, but because of irritating foliar fuzz, flannel bush should be enjoyed from a distance.

There is no way to say it delicately. Flannel bush, Fremontodendron californicum, is not easy to work with. It grows rapidly and rampantly with awkward form to about ten feet high and broad, but then starts to deteriorate when only about twelve years old. It can deteriorate even sooner if well irrigated. The fuzz on the foliage and young stems is irritating to the skin, especially during warm weather, so is very uncomfortable to handle. Otherwise, for out of the way spots, flannel bush is a striking native plant with impressively abundant bright golden yellow bloom this time of year. Neglected plants that do not get pruned or watered seem to be happier and more colorful, and can get older and much larger.

Six on Saturday: Native Range?

Valley oak, Quercus lobata, and Coast live oak, Quercus agrifolia, which I featured here last week, are the two formerly prominent native oaks of the Santa Clara Valley. I do not know if valley oak is native to the Santa Cruz Mountains above the Santa Clara Valley. It should be; and I should know for certain. However, I am not convinced. It is a chaparral species, not a forest species. The several old specimens in the Santa Cruz Mountains are on roadsides and in other situations where they seem to have been planted intentionally. Yet, this region developed mostly after the Great Earthquake of 1906, and not much was here prior to that, but some of the valley oaks seem to be a few centuries old.

1. A different perspective of the same valley oak from last Saturday conceals major storm damage that is otherwise so prominent. This really is a grand tree, in a perfect situation.

2. Although this is not a good picture, and does not seem to show much, it demonstrates how this tree is squarely centered within this view from the old depot baggage platform.

3. From the opposite side, the trunk obscures the baggage platform. Was it planted there intentionally? If so, why was it not centered on the window or doorway of the old depot?

4. It is just coincidence that the tree is situated so ideally on the edge of an area that was formerly used for parking? It was already old when cars still had horses in front of them.

5. Valley oak is such a grand tree. As big and sculptural as this specimen is, it is perhaps a century or so younger than the other tree. It was still quite small and shrubby in 1906.

6. Even the leaves are distinguished. The leaves of the trees in my former neighborhood had rounder lobes and sinuses. I do not know if such traits are environmental or genetic.

This is the link for Six on Saturday, for anyone else who would like to participate:

Beard Tongue

Beard Tongue does purple well.

With such a weird name, beard tongue is probably less commonly known by its common name than by the Latin name of Penstemon. Of the thousands of cultivars (cultivated varieties) that have been developed over the decades, most of those that are popular for home gardens are known as cultivars of Penstemon gloxinioides, even though their actual lineage is generally unknown. In recent years, other species have become more available.

Spikes of red, pink, purple or white flowers stand vertically above the foliage. Yellow flowers are still rather rare. Individual flowers are bisymmetrically tubular, with two conspicuous lips and a fuzzy tongue. Some beard tongue have relatively wide leaves and plump flowers, like really big snapdragons. Others have narrow leaves and thin flowers. Mature plants get only 1 to 2½ feet high and a bit wider, although some of the rare specie can get significantly larger.

Giant Chain Fern

Giant chain fern is remarkably resilient.

On the West Coast between British Columbia and Mexico, the largest native fern might be the giant chain fern, Woodwardia fimbriata. In sheltered and damp coastal forests, it can get taller than six feet, although it is typically about three feet tall and wide in home gardens. The lightly colored and almost yellowish green fronds generally stand upright and flare outward from the center. The foliage is doubly lobed and lacy, but quite substantial. The thick rhizomes spread rather slowly. Established plants are remarkably resilient. They can tolerate almost full sun exposure if watered enough. Those in partial shade can tolerate lapses of watering. However, they do not recover too readily from relocation or division.

California Buckeye

California buckeye resembles related horse chestnut.

Chaparral climates are not easy without irrigation. The long summers are warm and arid. California buckeye, Aesculus californica, knows what to do if it can not stay hydrated out in the wild. It simply defoliates. Yes, it goes bare right in the middle of summer. If it does it early enough, it refoliates after rain resumes in autumn, only to defoliate again for winter.

This ‘twice deciduous’ characteristic is likely why California buckeye is not more popular for unirrigated landscapes of other natives. Shade is an asset through warm summers. In coastal, riparian or irrigated landscapes, the original spring foliage lasts through summer to defoliate in autumn, like that of most other deciduous plants. It may get shabby though. 

Nonetheless, California buckeye is a delightful small tree, typically with a broad and low canopy suspended by a sculptural branch structure. Not many get more than twenty feet tall, although some get twice as tall. Bark is strikingly pallid gray. The elegant leaves are palmately compound. Six inch long trusses of tiny white flowers are sweetly fragrant in spring.

California Poppy

Wild California poppies are bright orange.

Even after so many pretty shades of yellow, red, pink and and white have been been developed, the natural orange of the native California poppy, Eschscholzia californica, is still the best. That is probably why they all eventually revert to orange after reseeding. Although native, they do not reseed everywhere, and actually seem to be more reliable in unrefined and unamended areas of the garden than in rich soil with generous irrigation. However, a bit of watering can prolong sporadic bloom until autumn. Bloom otherwise ends before warm summer weather.

California poppy is grown as an annual because the perennial plants get tired rather quickly. They fortunately self sow prolifically. Flowers are typically about two inches wide, with four petals. The intricately lobed leaves are slightly bluish. Foliage is not much more than half a foot deep.

‘Carmel Creeper’ Ceanothus

Such true blue color is rare.

Its narrow native range stays near to the North and Central Coast of California, including Carmel. However, its nomenclature is all over the map. The genus is Ceanothus. After that, the species name might be any combination of thyrsiflorus, griseus or horizontalis, or omitted. ‘Carmel Creeper’ is its cultivar name, with or without the species designation.
It is certainly no horror movie starring Clint Eastwood. Carmel Creeper is one of the more practical ceanothus. It spreads out laterally as a deep and densely foliated groundcover. With room to sprawl, it can stay less than three feet tall. Shiny evergreen foliage remains after the fuzzy denim blue bloom of early spring. Individual leaves are distinctly rounded.
Like all native ceanothus, or California lilac, California creeper ceanothus does not want much water once established. It dislikes major pruning too, so prefers areas where it can sprawl freely. Partial shade inhibits bloom and foliar density. Birds enjoy the cover. Bees enjoy the bloom. Unfortunately, even happy plants may not live longer than fifteen years.