Gardens featuring California native plants have distinct seasons. Spring is the time of new growth and wildflowers; we like to call it the ‘Growth Season’. It’s a lovely time, one we look forward to each year. But like all good things, the Growth Season is ephemeral. To learn more about the seasons in California gardens see: http://mother-natures-backyard.blogspot.com/2014/09/seasons-in-southern-california-garden.html.
Sometime in May (the timing depends on the weather and where you live in S. California), the garden begins to transition from spring to summer. You can see it happening before your very eyes. Spring wildflowers finish their blooming – or are completely done – and the cool season grasses turn golden brown. The days are longer and warmer, with a hint of the summer to come. This is the spring-summer transition.
The spring-summer transition is one of two busy times in the California native garden. The other is late fall (we’ll talk about that in October). These are clean-up, tidy-up and preparation times. The tasks are not unpleasant, and you can do them over a period of several weeks (from May to June). Once complete, your garden will look lovely; you’ll be ready to enjoy the outdoor celebrations of summer.
The main tasks of the spring-summer transition include watering, weeding/pest management, seed and foliage harvesting, tidying (including pruning) and checking, fixing and replenishing mulch and other hardscape. We discuss each of these separately below.
Trickle watering bucket makes selective watering easy.
If your garden is young (two years old or less), now is the time to seriously begin a summer watering program. The longer days, higher temperatures and wind can dry out a garden in a hurry. So check the soil – dig down 3-4 inches – and water if it’s dry.
When watering, choose a cool, overcast day. Review the 14-day weather forecast; if a cool, cloudy period is projected, that’s the time to water.
Even established gardens often include a new plant or two. These will need a little summer water, even if the rest of the garden is drought tolerant. The easiest way to water individual plants is with a trickle watering bucket (for instructions on how to make and use one see: http://mother-natures-backyard.blogspot.com/2015/07/surviving-drought.html). Alternatively you can water with a hose set to a trickle. Either way, you can water deeply, but selectively.
Oleander aphids and their predators on Milkweed.
If you have a young garden, you may be ready to give up at this point. Moist soils and warm weather provide perfect conditions for a number of pesky weeds. Take heart: pull weeds before they go to seed and prevent a bigger problem next spring. Weeding does become less of an issue as trees and shrubs shade out some of the sun-lovers. That and weeding really pay off in the future – so get out and weed in the pleasant days of May!
If weeds are popping up in the cracks, wait for a sunny day and spritz them with vinegar. It may take several treatments, but this old-time remedy really does work. Best of all, it’s cheap and safe.
In general, pests are less of a problem in water-wise native gardens. There are several reasons for this: 1) natives are less susceptible to their usual pests; 2) drier garden conditions deter some pests (slugs, snails and others); 3) native plants attract natural pest-eaters like birds and carnivorous (otherwise known as beneficial) insects.
That being said, the fresh new foliage may be attracting aphids, thrips and other chewing and sucking insects. Get out in the garden and look for them. Look also for the beneficial insects: the ladybugs, robber flies, lacewings and others of Mother Nature’s pest control squad.
Learn what the beneficials look like: the Ladybug larvae (which eat the aphids) look like little monsters (see above) but they are true garden heros. If you see adult Ladybugs on a plant, look for the larvae. The adults are laying eggs, and the larvae are likely present in sizes ranging from minute to larger-than-adult. Be thankful that you’ve got these voracious eaters in your garden!
If pests are overtaking a plant, then take action. As a first step, try blasting aphids and thips off with a stream of water. If that doesn’t work, use a mild insecticide – Safer’s Insecticidal Soap or a few drops of mild dish washing detergent in a liter of water. Native plant gardens rarely require anything stronger.
Late spring is important for seed collecting/spreading. After the spring-blooming plants finish flowering, they produce seeds. If you want your wildflowers to return year after year, you need to either let the plants reseed naturally or collect the dry seeds and store them. Learn more about managing annual wildflowers at: http://mother-natures-backyard.blogspot.com/2015/04/sustainable-gardening-managing-annual.html.
Annual wildflower plants (spent) used as mulch.
You may need to tidy the garden before all of the seedpods have opened. Here’s a trick we use: harvest entire annual wildflower plants (or trim seed pods from perennials), cut them up if needed, and use them as mulch. You may need to tramp the mulch down a bit for a tidier appearance; and you only want to use this mulch in areas where you want new plants to grow. This method works quite well for reseeding, and has the additional advantage of creating no-cost summer mulch.
Coyote mint (Monardella villosa) ready for harvest.
The spring-summer transition is one of two times a year (the other is late fall) when the garden can look a bit unkempt. A bit of tidying can make your garden safer and healthier, in addition to looking better. So get out your gloves and pruners to do a little plant maintenance.
We’ve discussed collecting seed from spring annuals above. We like to leave the annuals until most of the seeds have ripened. At that point it’s easy to pull up the dry plants and use them as mulch.
If possible, we also leave the seed pods and fruits on trees, shrubs and perennials, either until they are ready to collect or they drive us crazy – whichever comes first. Seed and fruit-eating garden birds depend on our gardens, particularly in times of drought. So hold back until most of the edibles are gone, then prune as appropriate. For more tips on pruning native plants see: http://mother-natures-backyard.blogspot.com/2012/11/pruning-common-native-plants.html.
Look over your trees and shrubs. Are there broken branches? Areas with disease? Crossing branches that are rubbing, causing damage? These problems should be remedied any time you see them. But the spring-summer transition is a good time to give your trees and shrubs a thorough review.
Pruning shrubs that have over-grown the sidewalk.
Some perennials may have grown exuberantly in spring, extending out over paths and walkways. Now is a good time to prune these back as well. Just give them a light pruning for human safety. We like to feather the edges of shrubs along walkways, rather than hedge-pruning to a straight edge. But whatever works with your garden’s style is fine.
Some shrubs and perennials are growing vigorously with the warm weather. If you want to create a bushier plant, tip prune branches during times of late spring growth. Catalina snapdragon (Gambelia speciosa), Lemonadeberry (Rhus integrifolia), the herbaceous mints (Mentha, Clinopodeum, Stachys) and California fuschia (Epilobium canum) all respond well to this treatment.
New mulch makes the garden look fresh & tidy.
Garden of Dreams Discovery Garden, CSU Dominguez Hills.
Late spring is also a good time to do routine hardscape maintenance. If using irrigation (of any type), now’s the time to be sure that everything is in working order. Replace broken or non-functional elements; test timers to see if they are functioning properly. You’ll soon need your irrigation system in good working order.
Late spring is also a good time to reassess your garden watering system/strategy. As native plants become established, they may need less water. Perhaps it’s time to replace your drip or conventional irrigation system with something less intensive. At the very least, move drip irrigation or soaker hoses to accommodate the growing root system of maturing plants.
This is also a good time to see if mulch needs replenishing. Organic mulches break down over the winter; you may need to add some new mulch atop the old. New mulch also gives the garden a tidy appearance. Even inorganic (gravel; rock) mulches may need occasional replenishment. At the very least, rake the inorganic mulch and remove spent organic matter to give a neater look for summer.
Late spring is a fine time to critically evaluate your paths and walkways. Are they safe? Functional? In the right place? Would additional paths make it easier for you to access the garden? Now is a good time to make changes or repairs – before the heat of summer begins.
Inspect walls, fences, patios, sheds and other hardscape. Make needed repairs.
Mother Nature's Backyard is ready for summer!
While the spring-summer transition involves some work, the results are so dramatic that you can’t help but appreciate them. So get out in the garden, put in a little extra time now, and enjoy the results all summer long.
Many garden plants are surprising us these days, despite the drought and blustery winds. Even some of the ‘gamble’ plants – species we planted despite their questionable suitability – are doing remarkably well. One such plant is the Wooly bluecurls (Trichostema lanatum, pronounced tri-KOS-te-ma la-NAY-tum), which is looking lovely in Mother Nature’s Garden of Health.
Wooly bluecurls belongs to the Mint family (Lamiaceae), along with the sages (Salvia species), the Pitchersages (Lepechinia species), the Woodmints (Stachys species) and other mints (Mentha; Monardella; Clinopodium/Satureja). Most Trichostemas are aromatic and have distinctive blue or purple flowers. Trichostema is limited to N. America; and of the 18 species, 11 occur in California, most of them annual wildflowers.
Several Trichostemas grow in Los Angeles County. The annual Trichostema lanceolatum (Vinegar weed) has been recorded from the Santa Monica Mountains, Catalina Island and the Palos Verdes peninsula. Trichostema austromontanum (also an annual) grows in the San Gabriel Mountains. The perennial (sub-shrub) Parish's bluecurls (Trichostema parishii), similar in appearance to Wooly bluecurls, can still be seen in the San Gabriels.
Wooly bluecurls (Trichostema lanatum) in natural setting.
Rancho Santa Ana Botanic Garden, Claremont CA.
Wooly bluecurls ranges from the Santa Lucia and Gabilan ranges of Monterey and San Benito Counties, to northern Baja California, Mexico, in the south. In Los Angeles County, it grows on Santa Catalina Island and in the Santa Monica and San Gabriel mountain ranges. It was formerly common on dry slopes below about 3000-4500' in coastal scrub and chaparral communities. Some very good Trichostema habitat has been lost to human expansion. There is evidence that this species once grew at lower elevations – places now covered by cities and suburbs.
The first recorded (written) sighting of Trichostema lanatum was by the Spanish explorer Fray Juan Crespi, in 1769.  The type specimen was collected by David Douglas, a noted plant collector in the western U.S. And the species was named and described in 1835 by George Bentham (1800-1884), eminent English taxonomist and long-time president of the Linnaean Society of London.  Trichostema lanatum was introduced into the horticultural trade by Theodore Payne.
Wooly bluecurls is an evergreen, perennial sub-shrub, growing 3-5 ft. (1-1.5 m.) tall and 4-6 ft. wide. The plants resemble the Mediterranean herb Rosemary. In fact, the common names for Trichostema lanatum include Romero (Spanish name for Rosemary), California rosemary and American wild rosemary.
When young (above), plants have several, fairly upright stems, and an overall vase-like form. The younger branches are a dark purple-red, providing a lovely contrast with the foliage. As a plant matures, it adds upright stems and becomes more branched; mature plants look more like mature native Salvias, with a mounded form. As plants age, the woody, older parts of the branches lose their foliage, exposing the flaky, gray-brown bark of mature stems.
To our eyes, Wooly bluecurls is a lovely plant at all ages. Unfortunately, it often grows quickly for about 3-5 years, then expires in local gardens. We’ll discuss the reasons why – and things you can do to insure a healthy life – below. But know that a mature Trichostema is a welcome sight – a rustic old-timer that adds character and a Mediterranean flair to any garden.
The new spring foliage is bright green; it darkens to a medium to dark green by summer. The leaves are narrow – even linear – 1 ½ to 3 inches (3.5 to 7.5 cm.) long and about ¼ inch wide. Leaves are shiny above and hairy-white below; and the leaf margins curl under. This becomes more pronounced in summer/fall – an adaptation to the dry season.
The most notable aspect of the foliage is its aroma. It is truly a fragrance of Old California; a bit of pine, a hint of lavender, a fresh sweet scent that is unique to Wooly bluecurls. Like many other aromatic plants, Trichostema lanatum has a long history of culinary and medicinal use.
The flowers of this plant are nothing short of spectacular! They grow along spike-like inflorescences at the end of branches and in axils along the stems. The flowering stalks provide striking vertical interest in a late spring garden. Mature plants can produce 50 or more purple spikes, beginning in April-May in the lowlands – into summer at higher elevations. The flowers are long-lived and make wonderful cut flowers. The spikes and flowers are covered with short, wooly hairs – hence the common name Wooly bluecurls. The flowering stalks are soft to the touch, an aspect that enchants children of all ages.
The flowers themselves are marvels of Mother Nature’s engineering. The petals are usually a bright royal blue, but range from white or pink to dark purple. Some cultivars (see below) have unique floral colors. As seen in the photo below, the entire flower is covered in short hairs, which may be white, pink or purple.
The calyx (fused sepals) of a typical flower is magenta, which contrasts nicely with the blue-purple of the petals. Like many hummingbird flowers – and the mints in general - the petals are fused to form a slender tube. Nectar at the bottom of the tube is accessible only to long-tongued pollinators like hummingbirds, large bees and the long-tongued larger butterflies.
The five petals are modified into two lips, the upper being deeply lobed (see photo). The sexual parts are exserted (extend out beyond the floral tube) in dramatic fashion, making the flowers quite showy and distinctive. This is yet another adaptation to hummingbird pollination: the pollen adheres to the heads and backs of nectaring hummingbirds. Pollen is transferred from flower to flower as a by-product of hummingbird feeding.
The seeds (four wrinkled nutlets per flower) are contained in a dry capsule. Trichostema lanatum is ‘fire-follower’; seeds require stimulus from chemicals in the smoke of burning Coastal Sage Scrub or Chaparral to germinate. If you want to grow it from seed, you’ll need to smoke-treat the seeds. Some propagators spread twigs of chaparral shrubs over prepared seed flats, burn the twigs, then water and plant the seeds. An easier method is to purchase smoke-infused filter paper (sometimes called ‘liquid smoke’) which is available on-line; the filter paper is soaked in water, which is then used to soak the seeds prior to planting.
Wooly bluecurls (Trichostema lanatum) in garden.
In most gardens, Wooly bluecurls does best in full sun. If you have a hot, inland location, you might have more success with light shade. Plants like a well-drained soil with a low nutrient content. So don’t amend your soil with compost before planting – and resist the urge to fertilize this plant. This is an easy species to kill with kindness!
The other tricky management aspect involves water – or the lack thereof. Trichostema lanatum takes about 2 years to establish (at least in our garden). It needs occasional summer water during those first few years. Thereafter it really needs to be summer dry. Plant it with other plants that need little/no summer water: Toyon, Fremontia, the local bush Salvias (Black, Purple and White Sage), California sagebrush, California buckwheat and the penstemons. Standing water, particularly in the warm season (late spring through fall), will kill this plant. Even a very wet winter can do it in!
If you have clay soil, try placing Wooly bluecurls atop a low berm to improve drainage. You might also place it in an area that naturally dries out quickly; perhaps along a pathway, next to a large rock or in an area with excellent air circulation. Then resist the urge to water in summer. Don’t worry: this is a born survivor that can take a long dry period, as long as it gets adequate winter water. Wooly bluecurls needs at least 15 inches of water per year, so supplement winter/spring rains in a droughty winter.
Also refrain from piling organic mulch in deep layers around Trichostema lanatum. A gravel mulch, no mulch at all (except that produced by the plants), or a thin (1 inch) organic mulch are what’s needed. Another good idea is to tip prune plants after blooming and seed set (late summer). This will produce a bushier plant, and is particularly important during the first few years. Be sure to tip-prune only – leave at least 6 inches of foliage per branch and never cut back into old, bare wood.
That’s really about all the management that’s needed. Placement and watering are the keys. Other than that, Wooly bluecurls thrives on neglect. That being said, this plant is a natural choice for difficult-to-water areas like hillsides. It does well in an herb garden with Mediterranean herbs. You can use the dried flowers and foliage to make a tasty tea. They would also make a nice addition to home-made soaps and lotions.
Madrona Marsh native plant garden, Torrance CA.
Of course Trichostema lanatum is lovely planted with its natural associates like the native Salvias, wildflowers, cool-season grasses and bulbs. Place in front of a backdrop of evergreen native shrubs to showcase the flowers and foliage. Flowering plants are truly spectacular when massed. Be sure to cut a few flowering stalks to use in May bouquets. The edible flowers can also be used as a garnish on cakes, desserts, etc.
You may be able to find several cultivars at local native plant nurseries and on-line. ‘Cuesta Ridge’ has pink-purple flowers, is a bit smaller and tolerates occasional summer water. ‘Susanna Bixby Bryant’ Trichostema lanatum, which has white flowers, is sometimes available from Rancho Santa Ana Botanic Garden’s Grow Native Nursery.
Wooly bluecurls (Trichostema lanatum) against darker foliage.
You might also want to include Wooly bluecurls in a medicinal plants garden. The blooming stalks are collected, bundled and hung upside-down to dry. The dried flowers and leaves are stripped off and used to make a tea for stomach upset and menstrual cramps. A tincture made from fresh flowers/leaves can be used as a linament for bruises (for more on making tinctures see: http://mother-natures-backyard.blogspot.com/2015/10/garden-of-health-making-tincture-for.html). We've tried this tincture on some nasty bruises; it really does numb the pain and reduce swelling and bruising. In the past, flowers and leaves were fried in oil to make a salve for pain. Powdered dried leaves were also inhaled as a snuff in treating coughs.
Limited modern scientific studies suggest that Trichostema lanatum does indeed have anti-inflammatory effects, at least in the test-tube. There is current interest in determining the relevant plant chemicals, and testing these for their medicinal properties. This is yet another example of an old medicinal attracting current interest. We may someday take cold preparations inspired by wooly bluecurls.
In summary, Wooly bluecurls is a remarkably attractive evergreen native shrub. Its flowers and foliage are striking, and the flowers attract some of our favorite pollinators. In addition, the plant has both culinary and medicinal uses. While Trichostema lanatum can be challenging – and short-lived – it is well worth including in your water-wise garden. This is truly an enchanting plant. Once seen you’ll be hooked - believe us on that!
The South Bay Water-wise Gardening Tour is fast approaching (Sunday, May 15th). This tour is a great way to get ideas for making your garden more water-wise. See ideas in action, talk to homeowners, be inspired.