Growing California Native Plants in Containers

Hybrid Monkeyflower thrives on afternoon shade on our porch

Container growing has many practical advantages.  Containers permit gardening in tiny places – even those with no accessible earth. Growing plants in containers can be easier for those with physical or time constraints.  Container gardening allows the gardener to tailor-make the growth medium to the needs of the plant. It also makes it possible to grow plants with very different water needs side by side.

Container gardening also has aesthetic benefits.  Carefully chosen containers increase the beauty of many gardens.  A well-placed container can serve as an accent or focal point; it can also provide attractive aromas or attract favorite pollinators.  Groupings of container plants can soften a stark wall, entry way or awkward corner.     Well-planned containers can even provide a spot of color for most of the year.

 

Camas bulbs are lovely in containers

 

But the big question for native plant gardeners is: can I grow my native plants in containers?  The answer is an enthusiastic but qualified yes.  We’ve grown a number of California natives in containers – and learned a few things along the way.  Here are a few tips for those considering container gardening with native plants.

1.   Start with the easy ones. Some plants are made for containers. We suggest starting out with the easy ones, then graduating to those that require more skill, time and patience.   Annual wildflowers, perennials from bulbs and corms, ferns and grasses/grass-like plants (rushes, sedges, reeds, cattails) are a good place to start.   Next easiest are the herbaceous perennials.   The most challenging (and those that require more work) are the larger woody shrubs and small trees.

 

Plants that require summer water - like these wetland plants
 - are easy to grow in containers

 

2.   Plants that tolerate some (or regular) summer water are easier than those that like to be dry.   In nature, many California native plants have extensive root systems, allowing them to utilize both shallow and deep soil moisture.  In containers, it’s easy to over-water plants that normally require no summer irrigation.

Pots of spring-flowering annuals and native bulbs (which must be summer dry) can be stored in a cool dry place over summer.  Other summer-dry container plants, including many Dudleyas, can watered sparingly if plants are moved to a shadier location.  But some summer-dry species, like White Sage, are very difficult to grow in containers in S. California.   Avoid trees and shrubs with strict summer-dry requirements.

3.   Avoid plants with very deep taproots.   These woody plants survive summer drought by tapping into water reserves deep underground.  No container is deep enough to mimic these natural conditions; such plants are easy to over-water in containers.   Plants with shallower taproots (for example, perennials like the California poppy) can be successfully grown in deep pots.

 

Lilac verbena likes some afternoon shade

 

4.   Plants that tolerate part-shade or shade are easier than plants that require full sun.  Containers in full sun – and the planting medium they contain – get hotter than garden soil.  And excess heat stresses plant roots and can ultimately kill a plant. 

There are some work-arounds, if you need to container garden in full sun.  Light colored pots, larger pots, and those with thick walls remain cooler.  Probably the best solution is double-potting (cache-potting). Be sure that the inner pot (the one which contains the plant) has a diameter several inches smaller than that of the outer pot.  Fill the space between the pots with vermiculite – or those plastic packing ‘peanuts’ – to insulate the inner pot.  

But the easiest solution, in hot mediterranean climate gardens, is to locate pots in shadier places – or at least move pots to shadier locations in summer/early fall.  Fortunately, many California native plants do fine in part-shade or filtered sun.  These include many annual wildflowers, perennials from bulbs/corms, herbaceous perennials, ferns, woodland shrubs and many others.

We suggest you try moving pots to a slightly shadier location during the hot months.  You can always move a plant back to a sunnier spot if it starts to get leggy.

5.   Choose the right size plant for the space, usually based on growth rate and mature size.  This advice applies universally, but is particularly important when choosing a native plant for a small area.  It’s much easier – and better for the plant – to choose one that’s the appropriate size.  Fortunately, smaller cultivars of many native favorites are becoming available.  Ask the advice of your native plant nursery-person.  They may be able to suggest good alternatives

 

Many natives growing in pots are on display at Rancho
 Santa Ana Botanic Garden, Claremont, CA

 

6.   Choose the appropriate container based on root characteristics. Both the size and the shape of the container can be important for growing natives successfully.  Garden ‘bulbs’, annual wildflowers and some perennials (ferns; succulents; many herbaceous perennials) have relatively shallow roots, and can be grown in a wide variety of containers.  For S. California, we suggest choosing containers at least 10-12 inches in diameter and deep; smaller sizes are too difficult to keep watered in our increasingly dry, windy climate.

Native shrubs and trees – even the smaller ones – require more care in selecting an appropriate container.  Many of them have relatively deep roots, in addition to the net-like shallow roots.  For them, choose a pot that’s deep enough to allow the roots to grow.  A deeper pot will also allow you to water more appropriately.  You can let the surface layer dry out between waterings, better mimicking natural conditions.

Learn as much as you can about a plant’s root system before choosing a container.  Ask your local native plant nursery-person for advice.  They may be able to suggest specific pots for the plant you’ve chosen.  More container choices – including deep containers – are becoming available each year.

7.   Tailor the growth mix to plant requirements.  Being able to tailor the growing medium to a plant’s needs is a major advantage of growing plants in containers.  We like to start with a basic potting mix; in our area, Kellogg’s All Natural Potting Mix or Kellogg’s Native Smart Planting Mix are good choices.  You can then amend the medium as needed, for your plants particular needs. 

To create a quicker draining mix add perlite; for a moisture-retaining mixture add vermiculite.  A sandy mixture can be achieved by adding some sharp (builders) sand, crushed rock (like decomposed granite) or lava rock.  For an excellent review of soil amendments see reference 1, below.

A richer, lower-pH soil (appropriate for forest-floor plants like native Huckleberries) requires the careful addition of peat moss, pine or redwood bark fines (finely ground pieces) or humus.   We suggest testing the pH of the potting soil before and after adding ph-lowering amendments, to be sure your mixture is in the appropriate range.  Test kits or pH paper are readily available in nurseries or where pool supplies are sold.

 

Native Wild rose (Rosa californica) likes regular summer
water  if grown in a containers

 

8.   Monitor soil moisture carefully, particularly in extremely wet and extremely dry conditions.  Plants in pots are more vulnerable to both extremes than plants grown in the ground.   If possible, move pots to a drier location if plants seem to be ‘drowning’ during periods of excess rain.  Keep close watch on your containers during hot, dry and windy conditions.  Even large pots can dry out in a hurry.  We sometimes water even large pots every other day – even daily – during the hottest times.

9.   Give container plants a little fertilizer.  The roots of plants grown in the ground continually reach out to obtain mineral nutrients.  Container-bound plants have no such option.  Even the least-hungry pot-grown native will need a little fertilizer sometimes.

Base your fertilizer regimen on the needs of individual plant species.  Those described as growing in ‘nutrient-poor soils’ won’t need much.  Start off with a once yearly dose of ½ strength liquid fertilizer.    You can always fertilize more often, if plants become nutrient deficient.

No need to buy unusual (or expensive) fertilizer (unless your plant requires a low-pH type).  We like the general purpose, liquid or water-soluble fertilizers; you can easily mix them with water to create a half-strength solution. Fertilize when the plant begins to actively grow – often in late winter or spring.

Plants that grow in leaf mulch on the forest floor, and those from riparian communities, like a richer soil.  You may want to try incorporating a time-released fertilizer into the potting soil each year.  We suggest starting with about half the recommended amount – you can always add more.  Just loosen the top few inches of soil and incorporate the fertilizer.  Alternatively, use the liquid fertilizer (half strength) several times during the growing season. 

 

Yerba mansa (Anemopsis californica) is a decorative
groundcover  that can be grown in a container

 

10.        Repot or replace container plants as needed.  If you’ve grown plants in containers, you probably recognize the signs that a plant needs repotting: the roots or plant are over-filling the pot, flowering decreases and the foliage may look a little less healthy.   You can often carefully lift a plant out of the pot to check if roots are becoming crowded.

Repotting a native is no different from repotting other plants.  Let the potting medium dry out a bit to ease removal.  Then carefully remove the plant, divide it (if appropriate) or replant in a larger container.  Plants that can be divided include native ‘bulbs’, grasses/grass-like perennials and those that reproduce via rhizomes or root sprouting.  Such perennials are frequently used as groundcover plants, but can also be grown in containers.  For more information on repotting perennials see ref. 2, below.

For more information on repotting native ‘bulbs’ see: http://mother-natures-backyard.blogspot.com/2017/02/gardening-with-california-native-bulbs.html

When repotting woody natives into a larger pot, we suggest upgrading to a pot of at least 6 inches larger diameter.  That way you won’t need to repot as often. Loosen the soil around the roots, and remove as much old medium as can be easily removed.  Prune off any roots that encircle the pot, and loosen other roots.  Then use fresh potting medium when planting into the new pot.

If you need to repot a woody plant back into the same pot, you’ll need to prune/thin the roots. This is done in the same way for native or non-native species. For more on repotting techniques see references 3-5, below.

 

The informal shape of Euphorbia misera works well with
 a traditional Mediterranean-style container

 

11.        Choose container styles that complement the plants and your architectural/garden style.  Containers can provide unique and stylish accents – or just fade into the background, letting plants play the starring role. Choose containers that work with your style/design and either complement or highlight the plants they contain.   Consider foliage, flower color and growth characteristics of the plants when selecting containers.

Attractive containers are now available in all price ranges. Or unusual, recycled ‘containers’ may be just what your garden needs. Think about the role you’d like the containers to play before you purchase.   You’ll likely be living with your choices for a while.

12.        Choose plants with ‘added value’.  When choosing between plants, select the one that provides food, habitat, medicine, craft materials and/or scent over one that is simply pretty.  Make the most of your limited space; that’s smart, sustainable gardening at its best!

For more on growing native plants in containers see:

Planning a Pot: http://www.slideshare.net/cvadheim/container-gardening-2014  

Captivating Containers:  http://www.slideshare.net/cvadheim/container-gardens-2015

Native Foods on the Small Side:   http://www.slideshare.net/cvadheim/container-gardens-edibles-2016-final

Beautiful Bowls: containers for color through the year:   http://www.slideshare.net/cvadheim/beautiful-bowls-2017f

 

 

_______________________

1. http://extension.umd.edu/sites/extension.umd.edu/files/_images/programs/hgic/Publications/HG42_Soil_Amendments_and_Fertilizers.pdf
2. https://www.todayshomeowner.com/how-to-repot-houseplants/
3. http://www.wikihow.com/Repot-a-Plant
4. http://www.finegardening.com/how-repot-container-plants
5. http://www.hgtv.com/design/outdoor-design/landscaping-and-hardscaping/repotting-an-overgrown-shrub

 

 

We welcome your comments (below).  You can also send your questions to: mothernaturesbackyard10@gmail.com

 

 

Plant of the Month (March) : Wild hyacinth (Blue dicks) – Dichelostemma capitatum

Wild Hyacinth (Bluedicks; Dichelostemma capitatum) - Mother Nature's Backyard: Gardena, California

One of the true joys of spring is the unfolding of the spring ‘bulbs’.  We spoke of gardening with California native bulbs, corms and rhizomes last month: http://mother-natures-backyard.blogspot.com/2017/02/gardening-with-california-native-bulbs.html.  One of the earliest – and easiest – of the local species is the Wild hyacinth (Dichelostemma capitatum).   The scientific name is pronounced dick (dike)-el-AH-stem-uh (or dick-el-oh-STEM-uh) cap-ih-TAY-tum.

Dichelostemma capitatum is known by several common names including Wild hyacinth, Blue dicks, Bluedicks, Common Brodiaea, Purpleheads and School bells.  It is one of the more common corm-producing perennials in California, with a range that stretches from Oregon to Arizona and New Mexico, and south to Baja California and Sonora, Mexico.  Its elevation range is also quite unusual: from sea level to 7000 ft. (2,100 m.) in California.   In fact, it can be found growing in nearly all California counties. 

Currant taxonomy usually places the genus Dichelostemma in the family Themidaceae (the Brodiaea family), along with Bloomeria, Brodiaea, Muilla and Triteleia – all perennials from corms.  But some taxonomists still include this genus in the family Lilliaceae (the Lily family) (1).   The species has two accepted sub-species: the Sparse-flowered blue dicks (Dichelostemma capitatum ssp. pauciflorum) and the more common Dichelostemma capitatum ssp. capitatum.

The Sparse-flowered blue dicks grows in deserts and desert scrub of Central and Southern California, as well as in Utah, New Mexico and northern Mexico.  Dichelostemma capitatum ssp. capitatum, the widespread subspecies, is native to western Los Angeles County and the Channel Islands, as well as much of California. It grows in a wide variety of plant communities including coastal strand, coastal prairie, mixed evergreen forest, chaparral, valley grassland, coniferous forests, oak woodlands, redwood forests, montane scree and on the fringe of coastal salt marshes and vernal pools.  The plants are more common in sunny openings and after a disturbance (fire; landslide; etc.). 

Wild Hyacinth (Bluedicks; Dichelostemma capitatum) - leaves

 

Wild hyacinth is a relatively small, herbaceous perennial with fleshy, strap-like leaves.  The foliage is low – perhaps 1 ft. tall or less – and leaves are usually sprawling and somewhat twisted.  The leaves of older corms may be nearly an inch (2-3 cm.) wide and a foot or more long.  Younger plants have leaves that are almost grass-like.  You can see leaves for a range of plant sizes in the photo above.

 

Wild Hyacinth (Bluedicks; Dichelostemma capitatum) - plants

 

In warm-winter areas, the leaves begin to sprout in winter, after the rains begin in earnest.  We often see them first in December in our part of S. California. After rapidly growing, the leaves begin to yellow at their tips just before the plants begin to flower.  Flowering usually begins sometime in February (but may be as early as January or as late as March) in the lowlands of western S. California; it’s as late as May or even June in colder parts of the state.  Flowering often commences after a period of warm dry weather.

Unlike some native ‘bulbs’, everything about Dichelostemma capitatum is slightly twisted or wavy – from the leaves to the flower stalks.  In fact, that’s one characteristic that differentiates Dichelostemma from the Brodiaeas, which tend to have straight stalks.  The flower cluster is also tighter than that of most native Brodiaeas.

Wild Hyacinth (Bluedicks; Dichelostemma capitatum) -
leaves and flower stalks are often twisted or 'wavy'

 

The leaves of Blue dicks are the ‘power plants’ that produce food to be stored underground in the dry season.  That’s why it’s important to let the leaves shrivel and dry of their own accord – after flowering is done and the weather turns warm and dry.  The energy for next year’s growth is stored in an underground corm – a thickened part of the stalk whose function is food storage. 

The corm of Dichelostemma capitatum looks something like a garlic bulb.  We’ve grown this plant for years – can’t believe we’ve never photographed the corms.  For a good photo, see reference 2, below.  When you dig up the corm, there often are offsets (cormels or cormlets), which are immature corms.  These may be attached to the parent corm or loose.   These will become mature, flowering plants in 3-4 years.

Wild Hyacinth (Bluedicks; Dichelostemma capitatum)
 flower cluster

 

Wild hyacinth has small, old-fashioned-looking flowers. Each plant sends up a single flowering stalk, with flowers in a ball-like cluster at the tip.  Since not all the flowers open at once, a single plant is usually in bloom for several weeks.  And if you have corms in areas with different amounts of light, those in the sunnier areas will often bloom first.     

Wild Hyacinth (Bluedicks; Dichelostemma capitatum) -
 close-up of flower

 

The flowers are ½ an inch across (or perhaps a little more), with six petals that form an open, bell-shaped flower. The petals spread wider as the flower matures over a week or so.  The usual flower color for our area is violet-purple, though the species may have white, pink or lavender flowers on occasion.   One unusual feature is the ring of pale, petal-like appendages that surround the six fertile stamens (see above).

Western Tiger Swallowtail on Wild Hyacinth
 (Bluedicks; Dichelostemma capitatum)

 

Umber Skipper butterfly on Wild Hyacinth
 (Bluedicks; Dichelostemma capitatum)

 

While the flowers have little scent (at least to us), they do attract hummingbirds and butterflies.  The latter range in size from Tiger Swallowtails and Monarchs to the early-flying Skippers (for more on these butterflies see: http://mother-natures-backyard.blogspot.com/2016/07/insect-postings-mother-natures-backyard.html).  There’s something utterly enchanting about a butterfly nectaring on the delicate flowers!

After flowering, Bluedicks flowers produce a number of small, black, irregularly-shaped seeds.  You’ll know when the seeds are ready; the seed capsule becomes dry and papery and the seeds start to fall out, of their own accord.  Bluedicks are easy to grow from seed.  If you want them to naturalize, simply scatter the seed  and rough up the soil a bit.  If you’re really pressed for time, just let Mother Nature do the work.  You can also collect seed, store in a cool dry place, then plant it with the winter rains.  For more on growing corms from seed see: http://mother-natures-backyard.blogspot.com/2017/02/gardening-with-california-native-bulbs.html.

Wild hyacinth also reproduces vegetatively, producing corm offsets (called cormlets or cormels).  You won’t see these unless you dig them up.  But they will produce new plants the next year.  New plants have grass-like leaves and don’t flower until about their 3^rd year.  We’ll get some good pictures of seeds and cormels this spring – guess we’ve just been lazy about photographing this common species.

 

Wild Hyacinth (Bluedicks; Dichelostemma capitatum) -
 easy to grow in pots

 

Bluedicks is one of the easiest native ‘bulbs’ to grow.  In fact, we heartily recommend it - even to those who’ve never gardened with bulbs in their life.  This species can be grown in just about any soil – in the ground or in containers.   It likes sun, but does fine under winter-deciduous trees and shrubs.  It can even be grown in dappled or bright shade – though the plants will be somewhat leggy.

The only real trick is the watering.  Like all native ‘bulbs’, Bluedicks needs adequate water in winter and early spring.  In a very dry winter, you may need to supply it.  Once plants begin to flower, or if leaves begin to yellow, it’s time to taper off the water.  This process happens naturally in a ‘usual’ S. California spring. 

But ‘usual’ is rapidly become unusual, and we’re often forced to begin supplemental irrigation in spring.  So just mimic the old days, and water your Bluedicks progressively less as weather warms up.  Once flowering ceases, really taper off; then stop altogether for summer and fall.  Bluedicks can take very occasional summer water, but need a summer/fall rest.  Corms that get regular summer water will rot.

Wild Hyacinth (Bluedicks; Dichelostemma capitatum) -
Madrona Marsh Nature Center, Torrance CA

 

So, how to achieve summer dry conditions?  Easiest, perhaps, is to grow Dichelostemma in containers that can be stored in a cool, dry place during the dormant season.  If you have a dry area of the garden – perhaps where you grow annual wildflowers and native grasses – Bluedicks would do well there.  Under water-wise trees that are winter-deciduous is another possibility.  But anyplace in the garden that you can allow to dry out between deep waterings can support this garden bulb.

 

Wild Hyacinth (Bluedicks; Dichelostemma capitatum) -
Garden of Dreams Discovery Garden, CSU Dominguez Hills

 

If you’re worried about drainage, plant your bulbs along a warm wall, pathway or around rocks or boulders.  Mother Nature’s Backyard has an abundance of ‘urbanite’ (recycled paving concrete chunks; Mother Nature’s Backyard was a former dump site for construction debris and paving from the old Carrell speedway, once located near the site).  We try to use these materials creatively in the garden.  Not only are they useful for bulb-growing, this ‘rubble’ reminds us that native plants can grow in even the most challenging of soils.  Trust us – the soil in Mother Nature’s Backyard contains more debris than we’ve ever seen in an urban garden soil!  Sobering – but encouraging!!!

 

Wild Hyacinth (Bluedicks; Dichelostemma capitatum)
 benefits from warm 'urbanite' - Mother Nature's Backyard

 

Like most native ‘bulbs’, wild hyacinth benefits from digging up the corms occasionally and thinning them (either by replanting or preparing a tasty delicacy – see below).  In the old days, wild animals and Native Californians dug up, scattered and replanted native ‘bulbs’ every few years. The digging also served to aerate the soil.  The disturbance helped the bulbs remain productive, and modern gardens benefit from similar practices (3).   Other than that, you don’t need to amend the soil – whatever you have will work just fine.   We add a layer of new potting mix atop our potted bulbs each fall.  Alternatively, give a dose of ½ strength fertilizer when the plants begin to grow.

Chicken wire protects native bulbs from hungry critters

 

If you have gophers, consider planting your bulbs inside a small ‘cage’ made of chicken wire.  This will keep the bulbs safe and won’t prevent them from growing normally.  If you grow bulbs in pots, we suggest making a chicken wire insert, cut to fit the pot, and laid atop the potting medium after planting.  You can cover the chicken wire with mulch if you like.  This will keep out squirrels, skunks and other pesky urban critters on the prowl for a tasty treat. 

Wild Hyacinth (Bluedicks; Dichelostemma capitatum)
with annual lupine: Madrona Marsh Native Plant Garden

 

Bluedicks is charming along walkways in spring, paired with annual lupines, California poppies and other native delights.  The purple flowers pair well with the yellows of Goldfields (Lasthena species) and Tidytips (Layia species).  Bulbs can be grown among the native bunchgrasses.  And they tuck in nicely around native shrubs.  We like to plant them close to pathways and seating areas – places where visitors can stop and admire them and their pollinators.

 

Wild Hyacinth (Bluedicks; Dichelostemma capitatum)
in spring garden: Madrona Marsh Native Plant Garden

 

The flowers are edible; use them raw as decoration in salads and on desserts.  But the most important edible portion is the corm.  Bluedicks corms were dug by the hundreds by native Californians.  In fact, bulb patches were managed as a food crop and revisited yearly; in some areas, particular patches were managed and harvested by individual families. These corms were an important source of starch in traditional diets.  Corms were usually harvested in the spring.

The corms can be eaten raw or cooked (4). They can be dried for storage or ground into flour to be used in baked goods or as a thicken agent.  They can be fried, boiled, roasted or baked.  Their flavor is mild and slightly sweet; the slower the cooking time, the sweeter the flavor. 

In summary, Dichelostemma capitatum is a great example of a California native geophyte (perennial plant with underground food storage organ).  It’s an easy choice for even the novice bulb gardener.  It comes back reliably, year after year; and it naturalizes, making it a good bargain as well.  The flowers are pretty and attract hummingbirds and butterflies. It’s a wonderful link to our natural heritage in many parts of California.  And the corms are an edible delicacy, worthy of the traditional and modern palette.  So, what are you waiting for?

Wild Hyacinth (Bluedicks; Dichelostemma capitatum)
Mother Nature's Backyard

 

For a gardening information sheet see: http://www.slideshare.net/cvadheim/gardening-sheet-dichelostemma-capitatum

For more pictures of this plant see: http://www.slideshare.net/cvadheim/dichelostemma-capitatum-web-show

For plant information sheets on other native plants see: http://nativeplantscsudh.blogspot.com/p/gallery-of-native-plants_17.html

__________________

1. https://plants.usda.gov/core/profile?symbol=DICAC5
2. http://encinitasnatives.blogspot.com/2015_11_01_archive.html
3. MK Anderson, and DL Rowney, Edible Plant Dichelostemma capitatum: Its Vegetative Reproduction Response to Different Indigenous Harvesting Regimes in California: Restoration Ecology [Restor. Ecol.], vol. 7, no. 3, pp. 231-240
4. Charles W. Kane. Southern California Food Plants: Wild Edibles of the Valleys, Foothills, Coast, and Beyond. Lincoln Town Press,  2013.

 

 

We welcome your comments (below).  You can also send your questions to: mothernaturesbackyard10@gmail.com