Dietes bicolor

[P. Kohn]

We have now got two very large plants of this species which are completely unwilling to even attempt to flower.  No trouble about getting flowers (and seeds) on Dietes grandiflora grown under identical conditions. Can anyone help ?

[Maggi Young]

The Pacific Bulb Society Wiki says :
"Dietes bicolor is an evergreen species growing from 60 to 80 cm from a creeping rhizome. It is found on streambanks, often among rocks, in light shade in the Eastern Cape, South Africa. It is a very rewarding species, with a long flowering season, from late April to October in the Northern hemisphere (October to December in habitat). Better in half shade in a Mediterranean climate, it grows to a large clump with time. Flower stalks are perennial and should never be cut, as they make new flowers year after year."

That suggests to me that it will enjoy a sunny position, with  moisture-retentive soil, in the UK!  The note about not cutting the flower stems is interesting - though perhaps not exactly applicable to your plants meantime.

[Hannelore]

Hello P. Kohn,

in my collection there are some Dietes iridioides. They flower like Neomarica's and Trimezia's (all tropical Iridacea) after giving a rather strong fertilization: Very little nitrogen, much phosporus, even more sodium and enough Magnesium. Liquid fertilizers are not to recommend, because for chemical reasons phosphorus compounds in the necessary concentration don't stay in a liquid for a longer time.
The fertilizer I use (a German product) is in form of cristals with NPK 6+20+30 +2 Mg. You should find something equal in your country; if not, send me a PM.

Best wishes
Hannelore