Nutrition of the Clivia
Presented at the first Clivia Conference held in Pretoria in September 1994
Fertilizer Horticulturist, Pretoria
[Fertilizer compounds are given in terms of NPK, as used in South Africa, and we have given the N:P2O5:K2O equivalents in brackets in each case - Connie and James Abel]
As the attraction of the clivia is not only in the once a year flowering period but also in the lush dark green leaves and the strikingly beautiful seeds, cultivation practises should be aimed at all three aspects.
While the whole spectrum of nutrients is necessary for normal growth the well composted soils in which clivias should be planted will provide ample levels of rnicro nutrients, extra applications of macro nutrients are however of vital importance.
Although all the macro nutrients are active in the whole plant, the major three are as follows:
Mainly responsible for lush vegetative growth and deficiencies are first seen in yellowing of lower leaves.
Necessary for good root growth and development. As competition can be very high, it is essential.
Definitely the most important nutrient as it affects not only the size and lifespan of the flowers and leaves, but also increases the resistance to disease and drought.
If we look at the physiology of the Clivia plant, the growth of leaves and flower stems occurs only at the basal area where especially calcium and potash again play a critical role. Deficiencies will result not only in shorter leaves, but in flowers opening when still between the leaves.
As the Clivia's natural habitat is the forest floor in full or dappled shade we can conclude that it has adapted to:
1. Soils high in organic matter or compost.
2. High level of specifically potash from detritus dropped from trees.
3. Humid soil conditions (not necessarily humid air conditions).
4. Very competitive growing conditions, by developing a strong root system.
5. Initiation of flowers probably from low temperatures rather than light stimulus.
Nutrition and cultivation practices should therefore be aimed at the above,
and in principle we should try to reconstruct the natural habitat.
It will always be advisable to have the soil analyzed before planting any
perennial plants such as clivias, but in general the following recommendatoins
can be made.
PREPARATION OF THE SOIL
Broadcast one hundred grams per square metre of a compound fertiliser like 4:3:4(33) [12-21-14] plus a generous amount (approximately ten centimetres thick) of organic material or compost. Take care to work or dig the fertiliser and organic matter well into the soil.
With the above preparation, both seedlings and mature plants need no further fertilising until well established.
When planting dig a good size hole arid mix the soil from the hole with ten grams of fertiliser, and enough organic material to make a sixty per cent soil to forty percent organic material ratio. Plant with this mixture.
When planting in pots, or repotting, the same sixty per cent soil to forty per cent organic material with ten grams of fertiliser per plant, or straight potting soil with ten grams of fertiliser per plant, can be used.
In all instances water well after planting.
UPKEEP OF PLANTS
At the beginning of the season, before the emergence of the flowers, spread fifty grams per square metre of compound fertiliser 4:3:4(33) [12-21-14], taking care not to get fertiliser into the crowns. Follow this with a five centimetre layer of compost (not manure). During the growing season spread ten grams of fertiliser 1:0:1(36) per square centimetre.
Always water well after fertilisation, otherwise damage to the sensitive feeder roots may occur. The compost will act as a mulch and keep the soil from compacting.
For potted plants, apply five grams (less for small pots) of 4:3:4(33) [12-21-14], plus a layer of compost. Remove some soil or repot if necessary. Follow this with three to five grams of 1:0:1(36) [18-0-22] fertiliser every six to eight weeks, and always water well afterwards. Remember with pots that too little is better than too much.
MICRONUTRIENTS AND FOLIAR FEEDING
With well prepared soil and yearly application of compost, micronutrients should not be lacking, but spraying or foliar feeding with a micronutrient solution could be beneficial.
Foliar feeding in itself will not give enough nutrients for robust plants, and must therefore only be complimentary to a fertilisation program in normal garden situations.
Seed and small seedlings should never receive fertiliser until well established, but soil prepared as for potting can be used to germinate seeds.