MP Filter Plus: protecting turf through winter and the “false spring” window
The Cause
Cool season turf actually “max’s out” on the amount of sunlight it can use. Clear winter days can be deceptively harsh on turfgrass. When soil temperatures are low, but days are sunny, turfgrass can experience Low Temperature Photoinhibition. Photosynthesis is impeded as there is not enough warmth to match the amount of light. This imbalance stops sugar production and starts production of Reactive Oxygen Species (ROS). If ROS get too high this leads to discolouration, leaf wilt and even death.
The common visual symptom is a purple / red leaf tint, caused by anthocyanins. Anthocyanins are naturally occurring plant pigments (blue / purple / red) that turfgrass produces under stress. Importantly, these pigments typically form only on leaf tissue exposed to light, which is why purpling is often seen on leaf tips and exposed canopy areas. The discolouration is magnified by any additional stress like drought and very low P.
High light intensity and low P
Cold
Warm
This effect is often seen during the autumn transition into winter and the “false spring” window, those periods where conditions look like spring (clear, sunny days), but the turfgrass is still functioning in a cold limited mode. After low light periods (e.g., shade or post‑winter), sudden exposure to bright light can intensify this response and slow recovery.
The Cure
MP Filter Plus is designed to help turfgrass prepare for stress, not just recover from it. The formulation combines turfgrass stress hormones, ascorbic acid and organic acids, and key trace elements (Zn, Cu, Co) to support stress signalling pathways and the synthesis of heat shock proteins (HSPs), molecular chaperones that stabilise proteins and cellular structures during stress. This support is relevant across all stress events.
Where it fits best:
Late autumn cool down periods where days are bright and sunny
During winter as stress / dormancy support
Late winter / early spring “false spring” conditions (bright days + cold limited turf response)
Any scenario where low light + cold temperatures compromise photosynthetic efficiency
The Proof
Quick Decision Guide
What you see on turf |
What symptoms indicate |
Where MP Filter Plus fits |
Timing cues |
|---|---|---|---|
| Purple / red discolouration on clear, cool days | Low temperature photoinhibition; anthocyanin protective response to cold + high light | Supports turf under UV / cold stress via stress hormones + HSP / stress pathway support; includes ascorbic acid for oxidative stress support | Autumn lead-in: begin late April / early May as part of dormancy / stress preparation |
| Turf “stalls” — slow recovery at low temperatures | Cold limited metabolism, with less capacity to respond to stress | Positioned as helping turf prepare for stressful periods by optimising stress signalling pathways | Apply as stress / dormancy support via monthly applications during cooler months |
| Cold + bright days, “false spring” conditions | High light + low temperature stress window, common in late winter / early spring | Positioned for stress events including cold + UV exposure; foliar pathway emphasised | Winter exit: initiate applications when soil temperatures are > 10–11°C |
| General pre-stress preparation — known stress ahead | Stress can include heat / UV / cold / drought / salinity | Proactive stress management, applied ahead of stress events | Apply 7 days ahead of a controllable stress event, such as a known event and / or water restriction |