Growing Clivia in Cold Climates

This is aimed at Clivia lovers in colder climates. While these plants can be grown outdoors in the ground as landscape perennials in parts of Florida and California, residents of most of the rest of the USA have to treat them as container plants.

First let me emphasize that your growing conditions -- and the associated problems encountered -- are going to depend very heavily on geography and season. Massachusetts growing conditions are a far cry from those in Southern California. If it is going on winter in the Northern Hemisphere, then it is starting Summer in the Southern Hemisphere at the same time.

Several possible causes for stunted peduncle development (failure of the scape stem to elongate normally) have been suggested. Various corresponding remedies have been proposed.

Possible causes appear to include: excessively high temperatures, excessively low temperatures, nutritional imbalances or deficiencies, excessively high light levels, low light levels, recent disturbance (division), and/or rot. Recent division and rot seem to speak for themselves.

My personal observations have been made in central Indiana, USA, where we have hot, humid summers (usual high temperatures ca. 86 to 90°F or 30 to 32°C) and cold winters (extreme lowest temperatures -10 to -20°F, which is -23 to -28°C). We grow our Clivia outdoors under shade in summer and inside heated greenhouses in winter. We have generally seen stunted peduncle development here only in hot weather, when off-season blooms stay down in the neck of the plant.

It has been said that bright light suppresses scape growth. We have tried moving plants to a lower light level location, without result. We in Indianapolis are at 40 degrees North latitude; the sunlight is not so intense here as at 30 deg. South latitude. In Pretoria or in Perth, the bright light might be acting to suppress growth; not here.

We have found that moving plants to a cooler location (inside an air-conditioned house) and feeding with soluble fertilizer is the most effective combination to induce the peduncle (stem of the scape) to extend normally. Potassium has been suggested to play a critical role in scape elongation; at high summer temperatures, it does not seem to help by itself.

At temperatures below 60°F, blooms do not develop readily. In winter, when it is time for the Clivia to start blooming, we raise the greenhouse temperatures to at least 60°F (ca. 15°C) at night but try to keep the daytime highs below 80°F (ca. 27°C). We feed at every watering with a very dilute solution of soluble high potassium fertilizer. Under these conditions, we rarely see any stunted scapes.

There are clearly several different causes to the stunted scape condition. What makes your Clivia stunt its scape may not be what is making my plant stunt. One size does not fit all!

Jim Shields