Weekly Report

24 March 2023

Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores


Grasses were moderate in Pretoria and high in Potchefstroom.  A strong spike for the allergenic mould, Cladosporium was seen in Potchefstroom.

Cape Town

Pollen concentrations were very low during this sampling period. Trees detected were gum (Myrtaceae), birch (Betulaceae), mulberry (Moraceae), karee (Rhus/Searsia spp.), Australian pine (Casuarina spp.) and waxberry (Morella spp.). Weeds were goosefoot (Chenopodiaceae), Pellitory-of-the-wall (Parietaria spp.), plantain (Plantaginaceae), knotweed (Persicaria spp.) and the daisy family (Asteraceae). Moulds were low.


The pollen strip did not reach the laboratory in time for processing so last week’s findings are repeated. Very low pollen concentrations were detected in the atmosphere during this sampling period for grasses, trees and weeds. Trees identified were waxberry (Morella spp.) and bushwillow (Combretaceae). Weeds were goosefoot. Moulds were very low.


Pollen in all three categories: Trees, grasses and weeds was found in low concentrations. Trees identified were Australian pine (Casuarina spp.), guarri (Euclea spp.), Cape Holly (Ilex spp.), gum (Myrtaceae), olive (Oleaceae), pine (Pinaceae), yellowwood (Podocarpaceae) and elm (Ulmaceae). Weeds were pigweed (Amaranthaceae), lily (Liliaceae), mugwort (Artemisia spp.), the daisy family (Asteraceae), the carnation family (Caryophyllaceae), sedge (Cyperaceae), spurge (Euphorbiaceae) and slangbos (Stoebe-type).  Moulds were low.


Grasses were moderate. Low tree concentrations included hackberry (Celtis spp.), cypress (Cupressaceae), mulberry (Moraceae), gum (Myrtaceae), plane (Platanaceae), karee (Rhus/Searsia spp.) and willow (Salicaceae). Weeds were sedge (Cyperaceae), erica (Ericaceae), iris (Iridaceae) and ferns (Polypodiaceae). Mould spores were very low.


Grasses were moderate again this week. Low tree pollen concentrations included poplar (Populaceae) and elm (Ulmaceae). Weeds were similarly low and only sedge (Cyperaceae) and goosefoot (Chenopodiaceae) were detected. Mould spores were extremely low.


The pollen strip did not reach the laboratory in time for processing and last week’s findings are repeated. Very little tree pollen was detected during this sampling period and only pine (Pinaceae) was seen in the tree category. No significant grass concentrations were observed during a week with three days of rain. Weed pollen was similarly sparse as the carnation family (Caryophyllaceae), ragweed (Ambrosia spp.) and plantain (Plantaginaceae) appeared in the atmosphere fleetingly. Mould spores fluctuated but were consistently low.


Tree, weed and grass pollen concentrations were uniformly low. Trees included gum (Myrtaceae), birch (Betulaceae), Australian pine (Casuarina spp.) and mulberry (Moraceae). Weeds were ragweed (Ambrosia spp.), ferns (Polypodiaceae), nettles (Urticaceae), sedges (Cyperaceae), plantain (Plantaginaceae), moss (Bryophites), mugwort (Artemisia spp.) and borage (Boraginaceae). Moulds were moderate.


Tree, grass and weed pollen levels were very low. Trees identified were Australian pine (Casuarina spp) only. Weeds were goosefoot (Chenopodiaceae), sedge (Cyperaceae), pigweed (Amaranthaceae) and erica (Ericaceae). Mould spores were very low.


Grass pollen reached high concentrations in the air during this sampling week. Low tree levels included pine (Pinaceae), palm (Areceae), cypress (Cupressaceae), ash (Fraxinus spp.), mulberry (Moraceae), gum (Myrtaceae), oak (Quercus spp.) and Australian pine (Casuarina spp.). Moderate weed concentrations included pigweed (Amaranthaceae), ragweed (Ambrosia spp.), mugwort (Artemisia spp.), the daisy family (Asteraceae), sedge (Cyperaceae), erica (Ericaceae), Pellitory-of-the-wall (Parietaria spp.) plantain (Plantaginaceae) and sorrel (Rumex spp). Moulds were moderate to high, with significant spikes for the allergenic spore Cladosporium.