Weekly Report

21 March 2025

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Summary

Grasses in the summer rainfall areas are decreasing except for Kimberley, where grasses continue their upward trend. Weeds and trees are low at all sites.

Cape Town

Low grasses, trees and weeds were seen. Trees included waxberry (Morella) and elm (Ulmaceae). Weeds were goosefoot (Chenopodiaceae), the daisy family (Asteraceae) and nettles (Urticaceae). Moulds were low.

Johannesburg Central

Pollen concentrations decreased at this site. Grasses were low. Low trees included false olive (Buddleia), persimmon (Ebenaceae), olive (Oleaceae), gum (Myrtaceae), pine (Pinaceae) and cypress (Cupressaceae). Low weeds included pigweeds (Amaranthaceae), the daisy family (Asteraceae) and sedges (Cyperaceae). Moulds were low.

South of Johannesburg (Vanderbijlpark)

Grass concentrations were moderate. Low trees included only birch (Betulus). Weeds were pigweed (Amaranthaceae), the daisy family (Asteraceae) and sedges (Cyperaceae). Moulds were low.

Pretoria

Grasses are usually moderate at this time of the year. Low tree concentrations would include mulberry (Moraceae), bushwillow (Combretaceae), white stinkwood (Celtis), karee (Rhus/Searsia) and willow (Salicaceae). Weeds might be the daisy family (Asteraceae), goosefoot (Chenopodiaceae), sedges (Cyperaceae), ericas (Ericaceae) and ferns (Polypodiaceae). Moulds are low. 5-yr means are shown.

Bloemfontein

Grass pollen at this site is generally high at this time of the year. Trees would be mulberry (Moraceae), poplar (Populaceae), elm (Ulmaceae), olive (Oleaceae) and acacia (Acacia-type). Weeds are likely to be pigmyweeds (Crassulaceae), sedges (Cyperaceae), plantain (Plantaginaceae), goosefoot (Chenopodiaceae) and ferns (Polypodiaceae). Moulds are low. 5-year means are shown.

Kimberley

High concentrations of grasses were seen. Low trees included monkey puzzle (Araucariaceae). Weeds were goosefoot (Chenopodiaceae). Moulds were low, but spikes for ascospores appeared in the air flowing rain.

Durban

Tree, grass and weed pollen concentrations were low at this site. No tree pollen was detected. Weeds included ragweed (Ambrosia) and ferns (Polypodicaeae). Moulds were moderate with strong spikes for ascospores, following rain.

Gqeberha

Grass, tree and weed pollen concentrations were low. Trees included persimmon (Ebenaceae), waxberry (Morella), gum (Myrtaceae) and karee (Rhus/Searsia). Weeds were goosefoot (Chenopodiaceae), sedges (Cyperaceae) and slangbos (Stoebe-type). Moulds were low.

George

Low concentrations were seen for all pollen categories. Trees included olive (Oleaceae), ash (Fraxinus) and waxberry (Morella). Moulds were low. Last year’s findings for the third week in March are shown as the spore trap is malfunctioning, but the repair of this spore trap will be completed next week.

Reference Range

Grass:      Low: 0-5       Moderate:      6-20         High: 21-200

Trees:      Low: 0-15     Moderate:    16-90         High: 91-1500

Weeds:   Low: 0-10      Moderate:   10-50         High: 51-500

Moulds:  Low: 0-900    Moderate:  900-2500   High 2500-25000

Unit: per cubic metre