'(False?) gloxinia' – all right, but looks a bit anemic and doesn't flower

[Low Altitude]

I have what is some kind of gloxinia either genuine gloxinia or 'false' glox, Sinningia speciosa. Its leaves look fleshy like an African violet, but thh flowers, when they come, large and are bell-shaped and variegated, white with purple trim.

I have propagated the mother plant, on the left in the photo below, by leaf cutting. The offspring plant, on the right, is now 2+ years old.

The offspring looks healthy enough, but it has never flowered and as you see, the leaves are smaller and much paler than those of the mother plant. They have had broadly similar care, light and water.

Any idea what to do to encourage robustness and blooming? Any recommended fertilization?

Last summer, I pruned it back often to discourage it getting rangey and straggly. It bushed up a bit, but not much, and it's still pale and flowerless. I can tell you that the mother has huge rhizomes underground, about which i have to be careful when inserting the probe stem of a moisture tester, but I never feel any such with the younger plant.

 

[Jewell]

Lovely variety of plants. The flowers sound amazing. I have a alsobia Dianthiflora that’s very similar.

Interesting the differences between the parent and offspring. Do you use African violet fertilize? Since you mentioned that the care and placement is similiar that might be a contributing factor. I’d also try exchanging plant placement. For my plants I find this sometimes helps.

 

[Low Altitude]

Thanks so much. I've just done a search for African violet fertilizer. One brand is 8-14-9; another is similar at 14-12-14; but a third offers a significantly different ratio, 10-30-20. Go figure! I have some general 'blooms' plant food that is 4-8-4. Maybe I'll try that, since I have it already?

The flowers look like this when they come. Gorgeous:

Thanks again!

 

[Jewell]

Thanks so much. I've just done a search for African violet fertilizer. One brand is 8-14-9; another is similar at 14-12-14; but a third offers a significantly different ratio, 10-30-20. Go figure! I have some general 'blooms' plant food that is 4-8-4. Maybe I'll try that, since I have it already?

The flowers look like this when they come. Gorgeous:

View attachment 74548View attachment 74549
Those are gorgeous flowers. I think your fertilizer should work. I just use my orchid fertilizer on mine.

 

[cpp gardener]

It could be the age of the plant, that would explain the lack of/small rhizome. It could be that the soil you planted it in is significantly different from what "Mom" is in. In that case nutrient levels and availability will be different and could be the explanation.

It's amazing how many different "specific plant" fertilizers there are and how the nutrient levels vary. In general, Nitrogen (the first #) promotes foliage development; Phosphorus (the second #) promotes blooming; and Potassium (the other #) is used by the plant for general over-all vigor. Nitrogen is the most soluble and deficiencies are most frequent, due to being washed out of the soil when you water. That's the basics, there are entire books and college degrees devoted to fertilizers, fertilizing, and plant growing. Remember plants can't read, so find an analysis that looks suitable for your needs and ignore the name on the bag/jar.

 

[Low Altitude]

THANK YOU!

Very much appreciate the synopsis of the three usual prominent elements in plant food.

I'm in a significantly temperate zone. 39ºN: much more variation in daylight hours summer/winter than at the equator. Not huge temperature variation, since these are houseplants. We are frequently told to lay off fertilization in winter when plants grow much more slowly.

Would you advise NOT to lay off feeding completely, though?

 

[cpp gardener]

It depends on any supplemental light and consistency of temperature. If you're depending on natural light then yes I would hold off until Spring.

 

[Low Altitude]

I have learned a bit about Sinningia speciosa ('false' gloxinia) over the last few months, by trial and error. The 'formula':

• Temperature: turns out to be important. Much above 80ºF / 27ºC, and it either won't bud at all, or the buds will stunt. If it flowers (at a lower temperature) then the temperature rises above 80ºF, the flowers wilt in hours and fall off.
• Light: NO direct sunlight, except maybe the weak low kind early in the morning and late in the afternoon. This may be an indirect manifestation of its temperature constraint: with its dark green, fleshy leaves, the plant absorbs heat readily from sunlight and is not good at dissipating it.
• Water: It likes consistently damp soil and seems nearly impossible to over-water. I water by immersion and I'm conscientious about draining, so the thing doesn't sit flooded, but I water whenever the needle on my water-meter goes about the 2/3 of the way to 'saturated' (scales on water meters differ).
• Fertilizer ('plant food'): It likes a 'bloom' fertilizer, meaning one rich in potassium. The one I've used is 0-5-7 in the NN-NN-NN nitrogen-phosphate-potassium format.