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Algerian Ivy

Algerian ivy is big and bold.

Like so many fad plants that were formerly too popular, Algerian ivy, Hedera canariensis, now has a bad reputation. Ironically though, it earned its reputation for doing what it does best. It covers ground rapidly and efficiently. The problem is that it never seems to stop. It creeps anywhere it can, and climbs trees, fences and anything else that it can grab onto.

Aerial roots of climbing vines ruin paint and stucco, and accelerate rot of wooden fences and walls. Vines that get between planks or into cracks between bricks cause significant damage as they expand. Shrubby adult growth that blooms and produces seed develops where climbing vines reach the top of their support, or spontaneously in sunny locations. 

Nonetheless, with diligent edging for strict confinement and to prevent climbing, Algerian ivy works well as a resilient evergreen ground cover for large areas. Once established, it excludes weeds, and tolerates quite a bit of shade. Shrubby adult growth is uncommon if vines can not climb. Climbing vines may be harmless on bare reinforced concrete walls.

Algerian ivy is neither as finely textured nor as shallow as English ivy. Its broader leaves are about six inches wide, with blunter lobes. They stand higher on longer and distinctly blushed petioles. Algerian ivy is rare in nurseries now, but inhabits old landscapes, from which it sneaks into adjacent landscapes. Variegated cultivars are slightly more passive. 

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Periwinkle

Periwinkle is pretty for a weed.

Dwarf periwinkle, which is a vigorous but manageable ground-cover here, is an invasive weed in other regions. Locally, common periwinkle, Vinca major, is the more aggressive sort. It naturalizes in riparian situations and damp parts of unrefined landscapes. Stolons can be difficult to pull completely from the soil. Seed disperses secretively but efficiently.

Periwinkle is almost never available in nurseries nowadays. It tends to infest gardens by sneaking in. Then, the foliage and bloom can be too appealing to eradicate. More plants are easy to divide from established colonies. Growth is tidier if mown at the end of winter. As it regenerates, it gets more relaxed, and finally gets floppy. It looks shabby if trampled. 

Periwinkle blooms with sporadic but delightfully clear blue bloom. Individual flowers are about an inch and a half wide. The evergreen leaves are an inch or two long. Wiry stems get a foot or two deep. Cultivars with white or purplish blue bloom were available before  

periwinkle naturalized. Periwinkle with foliar variegation still inhabits some old gardens. It is slightly more complaisant.

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English Daisy

English daisy or a British Invasion?

Garden varieties with fluffier white, pink or pinkish red flowers, and more mounding foliar growth, are popular annuals. With grooming, they might survive as short term perennials. The more familiar form of English daisy, Bellis perennis, though, is a persistent perennial that commonly infests lawns. Stems stay very low. Flowers are white with yellow centers. 

Some consider English daisy to be a noxious weed in turf. Others like its random drifts of white bloom on otherwise plain lawns. English daisy works nicely as a rustic component of mixed perennials too. The common weedy form is unavailable in nurseries, but is very easy to divide from established colonies. Once established, it is impossible to eradicate.

Bloom is most profuse about now, and can continue in random minor phases until cooler weather late in autumn. Sporadic bloom is possible during winter. Warm and dry weather during summer can inhibit bloom temporarily. English daisy prefers partially shaded sites and steady watering. Flowers are an inch wide. The spatulate leaves are less than two inches long.

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Lithodora

Lithodora has more names than colors.

Both the common and botanical names of lithodora are variable. Many know it as purple gromwell. The botanical name can be either Lithodora diffusa or Glandora diffusa. Many of the cultivars lack their species name after one of these two genus names. There might be less variety with the cultivars than with the names! Floral color is the primary variable. 

White blooming ‘Alba’ is uncommon. After all, lithodora is popular for its rich blue bloom, which ranges from light sky blue to indigo. As the name implies, ‘Blue Star’ flowers have a white edge around a blue center. ‘White Star’ flowers have blue around white. Flowers are tiny but profuse in sunny situations. The dense evergreen leaves are likewise small.

Mature plants are generally only a few inches deep and perhaps two feet wide. They can eventually get more than six feet wide by rooting as they migrate. Although they grow too slowly for large scale ground cover, they work nicely in a sunny atrium, around boulders, or with mixed perennials. Lithodora is susceptible to rot in pots or if watered to frequently.

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‘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.

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Covering New Ground Or Old With Groundcover

50506
Mock strawberry covers shallowly but densely.

As the simple name implies, ‘groundcover’ covers the ground. Groundcover plants stay lower than shrubbery, and function something like mulch. They insulate shallow roots of other plants, inhibit weeds, and some groundcovers inhibit erosion. Besides all their utilitarian functions, they provide appealing foliage, and some bloom nicely.

Lawn is probably the most common groundcover, and is also the most useful; but that is an entirely different and involved topic! Other groundcover plants are spreading perennials, plants with sprawling stems, or vines grown without support. Most are evergreen, since defoliated plants do not cover much of anything too well.

Gazanias and iceplants are popular perennial groundcovers. Their old stems tend to die out and decompose as efficiently as new stems pile up over them, which is why they do not get too deep. Gazanias can eventually get bald spots that need to be patched with new plants, or ‘plugged.’

(The debris from pruning the edges of easily rooted perennial groundcovers can be processed into cuttings known as ‘plugs’, which can go directly into bald spots. Plugs can be taken from dense spots if no edging is necessary. They should be watered regularly, or plugged in autumn to take advantage of rain while roots develop.)

Groundcover forms of ceanothus (wild lilac), juniper and contoneaster are really shrubs that extend their stems more horizontally than vertically. Honeysuckle and both Algerian and English ivies are vines that spread over the ground until they find something to climb. Their stems root into the ground wherever they need to.

Since most groundcover plants are naturally understory plants that grow below larger plants, many tolerate considerable shade. Periwinkle and the ivies are remarkably happy in partial shade. However, vines, particularly the ivies, will climb walls and trees for more sunlight if they get the chance.

Many of the perennial groundcovers and some of the vines are neater if mown or cut low annually. Periwinkle does not need to be mown, but can get rather unkempt before new growth overwhelms the old through winter. Mowing eliminates the old stems, and makes the new growth fluffier. Dwarf periwinkle stays too low to mow.

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Mock Strawberry

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Potentially invasive mock strawberry fields forever.

The small yellow flowers are the giveaway. Real strawberries have white or maybe pink flowers. Otherwise, mock strawberry, Potentilla indica, looks very much like wild strawberry, with similar small red fruits and neatly serrate trifoliate leaves (that are palmately divided into three leaflets). The berries are edible, but do not taste like much.

Like real strawberries, mock strawberry spreads efficiently by stolons. If watered occasionally and sometimes fertilized, it is probably a better groundcover than the common ornamental varieties of wild strawberry. It is invasive in some areas.

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Fan Flower

60727Only a few flowers are true blue. A few more are nearly blue, but slightly blushed with lavender. Of the latter group, fan flower, Scaevola albida, which is usually more lavender than blue, can be quite convincingly blue if conditions are just so. The semi-circular flowers (which are actually wide bilateral flowers) are most abundant in spring and summer, but can bloom sporadically all year.

The finely textured evergreen foliage is dense enough to function as light duty groundcover. Mature plants eventually get about four feet wide without getting deeper than a foot, and more typically stay less than half a foot deep. Outer stems pressed into the soil with their tips up should root and grow into new plants. Fan flower prefers regular but moderate watering. Shade inhibits bloom.

Fan flower only became available in the middle of the 1980’s. How appropriate for flowers of such distinctive style and color! The original common type is still the most reliable. Newer cultivars are not quite as resilient, and might not be as vigorous either. However, they are worth growing for their bigger and bolder flowers, and because they cascade better from pots or raised planters.

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Creeping Saint John’s Wort

90717This is not the dreaded aggressively invasive Saint John’s wort that has naturalized in other regions. Nonetheless, creeping Saint John’s wort, Hypericum calycinum, does precisely as the name implies. It creeps, and has naturalized to a less aggressive degree in many spots near the coast. Its vigor is an advantage to many landscapes, but might eventually displease adjacent neighbors.

Creeping Saint John’s wort is a somewhat rustic perennial ground cover that does not need much water once established. It naturalizes in coastal climates because it gets all the water it needs from annual rainfall there. Although evergreen, it looks best if mown as winter ends. It happens to be susceptible to rust, and mowing removes much of the old foliage the the fungus overwinters in.

One to two inch wide bright yellow flowers, with five petals and prominent stamens, start to bloom in June and continue into September. By that time, the paired leaves might be getting tired if not watered, or infested with rust, but should stay presentable until mowing at the end of winter. Crowded plants might get three feet high. Otherwise, growth does not get much more than a foot deep.

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Garden Verbena

60629It is fair to say that garden verbena, Verbena X hybrida, is a reliable warm season annual. It gets planted in spring to spread out and bloom through summer with bright pink, red, purple or almost blue, or softer pastel pink or pale white. It is commonly replaced with cool season annuals by late autumn. However, garden verbena is actually a short term perennial that can survive winter to bloom for a few years.

Perhaps individual plants do not last long enough to be practical as permanent ground cover. Yet, if mulched just so, the thin branches can root where they touch the ground, and then grow into new plants to replace the original plants before they die out. Stems do not spread or cascade much more than a foot from where they are rooted. Nor do they stand more than six inches deep.