Is Streptocarpus flowering seasonal?

Streptocarpus 'Harlequin Blue'

Story # 124, Part IX,

            Is Streptocarpus flowering seasonal?

            With modern Streptocarpus hybrids we don’t worry about day length to induce flowering.  They are day neutral and will flower at any time of the year.

            Some Streptocarpus species may be seasonal but it’s hard to know if it’s day length.  It seems to be more temperature related --- like cool nights or drought related --- rainy season.

            My observed conclusion is that ultimate flowering is in months March and October.  They do the best when grown bright and cool.  So grown through the cool winter, they respond to the higher light intensity of March, April.  Grown across late summer, they respond to the cooler nights of October, November.

            There is no reason to have selections that don’t flower year around.

Does anything count more than bud count?

Streptocarpus 'Cape Essence'

Story # 124, Part VIII,

            Does anything count more than bud count?

            The way to get big flower power is either big flowers or with many small flowers.

            Bud count in Streptocarpus is genetically variable.  You can get from 1 to 24+ flowers per spike (peduncle).  Buds are formed in pairs up the stem in succession. 

            Because we know that high bud count is possible, there is no reason to release hybrids that don’t have a reasonable amount (2-4, 4-6).

            The trade-off is flower size which can compensate for lower bud count.  Stem strength and length are variable too but we don’t pay much attention to it.  S. ‘Mary Sakamoto’ is one where the huge flowers are too heavy for the stems, requiring staking. 

            Sometimes you may have a flower with color, shape or size that must be saved.  But the variety should not be release with a bud count of one.

            High bud count is genetically possible so we should move in that direction.

                                      

                                       Streptocarpus 'Mary Sakamoto'

Symmetrical leaves in Streptocarpus

Streptocarpus 'Heartland's Baby Kisses by Dale Martens

Story # 124, Part VII,

            Symmetrical leaves in Streptocarpus.

            Streptocarpus grow with one long leaf and one short leaf per fan.  The result is unsymmetrical clusters of leaves that are unwieldy. 

            Some Streptocarpus species are very symmetrical and have been dubbed ‘star’ shaped so we know that uniformity is genetically possible.

            No one is worrying about this symmetry yet but it is there waiting to be transferred into breeding lines.

Streptocarpus with a head of flowers

Streptocarpus 'Rose Halo'

Story # 124, Part VI, 

            Which is better --- a flush of flowers or continuous flowering?

            The first Streptocarpus hybrids I had 40 years ago like ‘Constant Nymph’ were continuous flowering but you would be lucky to have more than one or two flowers open at a time.

            Some varieties now will get a flush where 4-5 flowering stems will open together giving a big show then recycling later with another flush.

            Which is better?

Commercial crops are selected for uniformity and maximum flower power.  If we’re going to attract buyers we need a flush of flowers that last!

Non breakable leaves on Streptocarpus

Streptocarpus 'Myfanwy'

Story # 124, Part V,

            Many Streptocarpus with pretty flowers have long or wide leaves that break with handling.  Commercial crops are often sleeved for shipment and sometimes sold that way.  If the plant has long non-flexible leaves, they crack and break, leaving a mess.

            I don’t know of any Streptocarpus with flexible leaves but we have varieties with short leaves.  We could have wide leaves if they were short.

            Some of you are cringing.  Short and fat leaves with flowers coming out of the center sounds like we are trying to make it look like an African Violet.

            Trust me, Streptocarpus flowers on a compact plant will not be confused with a violet.

Hang-on-tight Streptocarpus flowers

Streptocarpus 'Fernwood's Cherries Jubilee'

Story # 12 4, Part IV,        

Hang-on tight flowers.

        We know that some Streptocarpus flowers stay attached to its calyx better than others.  It appears to me to be a mechanical problem.  But it is genetic and can be selected for.

       A secondary problem is accidental self-pollination.  This happens when the positioning of anthers (pollen sac) are in direct line with the stigma (female receptor) as the style grows out through the corolla.  The stigma runs into the anthers, breaking them open and the pollen falls onto the stigma causing pollination.

   So what?

    When a successful pollination occurs, the physical response is that the corolla detaches --- flower drop.  This is just as serious a problem as weak flower attachment.

     Simple solution ----- only select varieties that have hang-on- tight flowers.  If you select a must have pretty flower with flower drop, cross it into tight flowers until you get the corolla to stay on.

     Hang-on-tight flowers ---- It’s mandatory!

Heat tolerance in Streptocarpus

Streptocarpus 'Jealous Heart' - very heat tolerant

Story # 124, Part III,

            We know that Streptocarpus wilt in temperatures above 85 degrees F.

            Is this a problem?

A.     Yes.  They are difficult to produce in the summer in the North and most anytime in the South’s heat.

B.    No.  They do best in bright and cool so just produce them September to June.

     No plant performs to its ultimate all year around so be happy with what you get.  Each has its season.

     It’s technically possible to produce Poinsettias year around.  But why would we want to?

     Heat tolerance is not what’s holding back Streptocarpus but it certainly would improve the plant’s year around survivability.