Succulents: Survivors of the Winter

Aloe spp.

When planning for hot and dry condition planting, succulents are often among the top candidates because of their ability to withstand prolonged periods of drought.  On the other when it comes to planning for winter interests, seldom do they ever get recommended.  This could be because of an unspoken assumption that when a plant is heat tolerant, it does not like the cold.  This assumption is not valid.  Like all gardeners who have grown some of them, I can say that with the appropriate variety and suitable location in the garden, succulents can be among the few interesting plants in the dead of the winter.  While the rest of the traditional plants go into dormancy, some succulents continue to grow changing their colors in response to the temperature and light intensity.

Echeveria 'Neon Breakers' (Fall)

Echeveria 'Neon Breakers'  (Winter)

Succulents cover a wide range of plant species that originated from places of varied climes.  Some have come from the tropics (rain might be prevalent but some succulents grow on trees where the roots cannot reach the ground); arid regions (deserts have low rainfall and high temperatures that limit water supply); coastal areas (water may be available but it is usually loaded with high levels of salts and minerals - beyond the threshold levels for most plants); and the alps (precipitation may come fresh in relatively larger quantities but it is frozen and unavailable for plant consumption).  With that in mind, it is not surprising that some succulents respond differently under varied  environmental conditions. And that is why, some succulents can be winter gems even in temperate areas.

Aeonium 'Kiwi'

      Sedum rubrotinctum 'Pork and Beans'

Succulents is the collective term for drought-tolerant plants with the characteristic thickened fleshy organs (leaves, stems, or roots).  Whether the plants evolved (over the years) to come up with this type of specialized fleshy tissues as survival mechanism or whether they were originally endowed with such characteristics the first time they sprouted in the Garden of Eden, I am not sure.  However, if such character traits of succulents allow them to survive the extreme dry conditions, how much more would they favor the plants that are grown in gardens where almost everything is manipulated to provide favorable conditions for the plants?

Wooly Rose (Echeveria cristata 'Doris Taylor')

California is known for its generally mild climates but my garden - being in the foothills of the Sierras - experiences both ends of the thermal spectrum.   We have very hot summers and freezing winters.  Over the years I have observed that only few of the succulents in my collection are susceptible to the cold.  In fact most of them are very resilient and they display very interesting colors during the colder months.


Aeoniums, Sempervivums, Aloes, and Sedums are among the ones that consistently do well in my garden.  Others like Echeveria also do well depending on variety and microclimate. The earlier they get the morning sun, the better - as this would shorten their exposure to freezing temperatures.  Although succulents prefer some amount of shade in the summer, plants that are placed on the south-facing side of the garden have a better chance of withstanding the harsh winter nights.

   

With the right variety and microclimate, succulents can be the garden gem that sparkles in the winter.

Streptocarpus: My Own Plant

Streptocarpus spp.

Family: Gesneriaceae

Common Name:  Cape Primrose

Country of Origin: South Africa, Madagascar and  Asia

Fig.1    Streptocarpus flowers intermittently throughout the year.

It's been two and half years ago since I first saw a Streptocarpus in full bloom and the plant was not mine.  This time I have a clone of that same plant which has been growing in my kitchen.

Streptocarpus is probably one of the most beautiful flowering houseplants.  It is regarded in high esteem by plant enthusiasts not only because of its pleasing beauty but also because of its durability  as a plant. It is an evergreen, herbaceous  plant that grows well in shade - making it a great indoor plant.  This stemless plant blooms almost throughout the year as long as it is regularly fed with complete fertilizer (preferably with a high phosphorous content). They are related to the African violets but have a different morphological structure that makes them more appealing than their shorter relatives.

Fig. 2     Flower buds originating from the petiole of a leaf.

One of the most interesting observations on Streptocarpus is that flower buds originate from the basal section of the leaves (Fig. 2).  That's right; the flowers emerge from the leaves.   The first flower bud always grows closest to the axil as seen on the picture above.  The flowers come in clusters and indeterminately arranged on long slender peduncles that extend well above the top of the leaves giving the appearance of floating flowers (Fig. 3 and Fig. 1).  The flowers open in succession which allows a prolonged flower show (Fig. 1 and 5).

Fig.  3.  Clusters of unopened flowers.

Fig. 4  Delicate tubular flower on slender peduncle.

The flowers come with a delicate tubular corolla which extends out into deeply scalloped lips that resemble individual petals (Fig. 4).  The tube of the flower is usually clear white with increasing pigmentation towards the lobes with the lower lips being darker than the upper lips.  The peduncle (stem-like structure that supports the inflorescence) starts out curled and slowly uncurls as it elongates to display the ethereal inflorescence (Fig. 4).

Fig. 5     Flowers open in succession

Cultural Management  

1.  Provide sufficient moisture but not soggy soil.  Over watering is a common cause of damage on the plant.  Water only when the top of the soil feels dry.  

2.  Position plants in light but not direct sunlight.  East facing window sills work best.  Putting plants on a hot sunny window sill will cause burning on the leaves. 

3.  Feed regularly.  Fertilize during watering using low fertilizer concentration (about 25% of recommended rate).

4.  Allow sufficient room to grow.  Divide or re-pot only when the pot is full of roots to the next size using peat-based multi-purpose media.

5.  Deadhead regularly.  Remove spent flowers (including dead leaves) to encourage continued flowering and to avoid Botrytis (Gray Mold) infection.  

6.  Monitor the occurrence of pests.   Regularly inspect plants for white and greenflies, aphids, mildew, and mealy bugs. (These pests can be a problem but so far I have not seen them on my plants.)  It is easier to control pests at the early stage of infestation.

Streptocarpus: a sturdy and delightful flowering houseplant.

HortiCOOLture - Armored Plant

Fig. 1   The bizarre porcupine tomato (Solanum pyracanthum).



Ornamentally Odd
When all the basic plants are in place in the garden, an oddity here and there is in order.  This week our local nursery is offering a plant that would fit the bill.  The "Porcupine tomato" botanically known as Solanum pyracanthum (Fig. 1) is a plant that is armored with spikes all over. 

In spite of being prickly, some ornamental features can be attributed to this plant.  The bright orange spikes provide a pleasing textural and color contrast against the bluish green velvety leaves (Fig. 2).  The royal purple petals are complemented by protruding yellow stamens in the middle.   Eventually, small cherry-tomato-like fruits will take the place of the colorful flowers. A plant with such attributes definitely makes a statement in any garden.

Fig. 2   Dagger-like spikes on land under leaves of Solanum pyracanthum

Physical and Chemical Threat
This may be an ornamental shrub but the plant is definitely for your eyes only. The velvety green leaves may look soft and friendly but the dagger-like spikes (Fig. 2) that are spread all over the plant  make the plant look utterly foreboding.   I would not recommend this plant near playground areas.  The quills would deter any one from touching the plant but the danger does not end there.  The plant is known to contain various toxic substances on the leaves, stems and fruits - just like most solanaceous (night shade) plants.   Because of this, it is not clear whether the spikes were meant to protect the plant from humans and animals or vice versa. 

Fig. 3  Solanum pyrachantum flower.

 

 Fig. 4   Armored fruit of Solanum pyrachantum. (Photo from Rob's Plants)

 

 

Threat of Invasion

The plant is drought tolerant therefore caution should be observed when it comes to cultivating this plant since it can be invasive depending on the growing conditions.  The fruits are loaded with seeds which when allowed to mature and fall on the ground will result in an explosion of new seedlings.  Eradicating an army of plants like this, would involve a bloody battle.  :)  

 Solanum pyrachantum, although related to food crops like potato, tomato and eggplant, has been cultivated solely as ornamental plant.  And we will keep it that way! 

Plums for the Season

Santa Rosa plums (Prunus domestica 'Sana Rosa').

Baskets of dark ripe plums have always been one of the defining marks of summer in our home.  In some years we need smaller baskets than others, but there never was a year when we did not have plums ever since we planted the tree.  Traditionally, I would preserve enough plum sauce for us and our extended family.  This year, I did not get to do any canning (except for a couple jars of plum syrup) which I hurriedly make on the day we left for Taiwan.  It was a good thing that our friends from church came to pick them while we were gone - at least the fruits were consumed and not wasted.

One week before harvest.

Towards the southern side of the plum is a mulberry tree which is growing at a very fast rate. It will have to be trimmed if not pollarded so as not to jeopardize the productivity of the plum. 

 

My daughter is perched on the mulberry tree.

 

The garden presents a never-ending list of opportunities and challenges that varies from season to season.  The gardener may never master the garden but with persistence, every experience is an added arrow into his quiver.

Edibles in Bloom

Fig. 1   Thai Basil (Ocimum basilicum)

This is a partial glimpse of my vegetable garden this year.  Instead of showing the fruits, I chose to focus on the flowers.  Flowers are generally the early indicators of a forth coming harvest for any food crop.  For some plants such broccoli and cauliflower, the flower directly translates to the crop yield. Still for other annual plants where the leaves are the harvestable parts, flower initiation marks the cessation of productivity. 

Fig. 2    Cilantro (Coriandrum sativum)

Basil
Basil and cilantro (Fig. 2) are among of my favorite herbs of all times.  Basil is generally a summer crop and a long-day plant, which means that it flowers when the daylength (photoperiod) is longer than 12 hours per day. Thai basil (Fig. 2) is particularly sensitive to increasing photoperiod - the seedlings almost always have flowers when I buy them from the nursery.  For a plant where the leaves are the harvestable/edible part, this poses a problem.  However, that is when management comes into play.  It is my practice to  decapitate my basil plants at the slightest hint of flowering in order to induce branching and prolong vegetative growth. 

Fig. 3    Meyer Lemon (Citrus x meyeri)

Citrus
The 'Meyer' lemon seems to be enjoying its current location (Fig. 3).  When my father-in-law and his wife could not get it to fruit in their shady front yard, they gave it to me - knowing that we have the sun here.  So far it is looking good. 'Meyer' lemon, which is believed to have originated from China, is different from the true lemons such as 'Eureka', 'Lisbon', and 'Ponderosa' in that it is sweeter and less rindy (thinner rind).  Such characteristics are attributed to a genetic relationship to the Mandarin orange.
Now there are two types of lemons in my backyard.  I have yet to succeed in growing the Filipino lemon - Kalamasi (Citrus microcarpa).  



Fig. 4     Celery (Apium graveolens)

Celery

Last winter I planted a row of celery (Fig. 4).  It was great to have something green in the garden during the dead months of winter.  It was but we could not use it all up.  I left the plants to flower to encourage the pollinators to linger around.

   

Every gardener in our area would be interested to know that celery is deer resistant.  But then again - as I always say when people ask me whether a plant is deer resistant or not - it all depends on how hungry the deer are. 

Fig. 5    Italian Sweet Pepper (Capsicum annuum)



Fig. 6     Phaseolus vulgaris

Beans

Not all good things are meant to be for the gardener. I planted beans and watched them grow all the way to flowering (Fig. 6). One morning after I took the picture above, all those plants were defoliated. Everything above ground was gone except for the stems. To say that I almost cried is an understatement. The voles are here and they are destructive! Some say that voles come every three years; 2012 appears to be third year. Sadly, we'll have no beans this summer.

Fig. 7   Thai Pepper (Capsicum annuum)

Fig. 8     Fingerling Potatoes (Solanum tuberosum)

Potatoes 

From last year's harvest, I saved the really small tubers and planted them in early spring.  If it is still true that the condition of the foliage (Fig. 8) is an indication of what lies underground, then these spuds must be hiding some gold in the ground.  Unless, of course, my enemies (voles) have dig a secret tunnel to get to the tubers.  

Fig. 8     Tomatillo (Physalis philadelphica)

Tomatillo

This is my first time growing tomatillo.  So far the plant is doing what it is supposed to.  Flowers hang from the branches but there has been no sign of fruit as of this time.  I keep my fingers crossed on the possibility of homemade salsa verse. 

What's flowering in your edible garden today?

Spotted Bells

Fig. 1     Spotted bellflower (Campanula punctata)

Campanula punctata.   Bell-shaped flowers that dangled from slender stalks periodically grabbed my attention as I roamed my mother (in-law)'s country garden in Fortuna, California.  Campanula punctata (Fig. 1) has flowers (either white or pink) that are tinged with fine purplish dots which make them appear delicately translucent.  (These dots are the distinguishing characteristic of the species punctata).  The scalloped edges of the corolla are lined with delightful trichomes.  I suppose that they function, among others, to aid pollinators in reaching their desired destination. 

 

Fig.  2     Campanula punctata grows in the shade.

 Sun Exposure.   I observed that the plant was growing in both full sun and shady areas of the garden with no obvious growth difference.   When it comes to determining whether a plant is good for the shade or full sun areas, the determining factor is usually their water requirement.  When a gardener can assure that the plants get enough (not too much) water regardless of position in the garden, then the plants can perform well regardless of sun exposure.  The plant has soft tissues hence drainage is important in order to avoid rotting of the stems. 

Fig. 3      Showy display of white flowers

Growth Habit.  This perennial plant is a moderate grower and a vigorous self-seeder.  (I know this for sure because when I visited the garden a year ago, they were not there, but this time they were all over the place.)  The plant multiplies itself in two ways - creeping rhizomes and traveling seeds.  Regular division is necessary to promote good plant vigor.  In as much as blooming occurs in spring to summer, it is best to divide the plants in the fall. 

I brought home some rhizomes of this plant for my garden.  I imagined that they would look great in the shady "Down Under".  Unfortunately, the voles got to them before they had a chance to get established.  Sad.

 

There are hundreds of species in the genus Campanula; which one have you tried in your garden? 

Visiting the World Vegetable Center

AVRDC (Asian Vegetable Research and Development Center)

At last I made it to AVRDC - The World Vegetable Center!  Coming to this place has been a long dream especially when I was working as a plant scientist in the Philippines.  Hence, this is a dream come true!
My family was given an exclusive seminar by Maureen Mecozzi, Head of the Communications and Information Department.  Later on Willie gave us a tour of the research facility.  It was indeed a great experience for all of us.

Willie (L) gave us a tour of the research center.

I'll write more about AVRDC - The World Vegetable Center later.