Last week in our horticulture community, discussions spanned a range of practical and theoretical topics. Members shared strategies for adapting urban spaces with small greening grants, debating the efficacy of hedges as a sustainable alternative to traditional lawns. There was also a lively exchange about the reliability of handheld nitrate meters. In addition, enthusiasts explored the history of greenhouse biocontrol and its evolution. The community also delved into advanced training opportunities in VPD and PID tuning, essential for optimizing plant environments and processes.
This Week’s Hot Topics
Small urban greening grant templates
Members are exchanging templates and tips for securing small grants aimed at urban greening projects. This is a valuable resource for anyone looking to enhance green spaces in urban settings. Read more here
Hedges instead of lawn for heat
The discussion on replacing traditional lawns with hedges to mitigate heat is gaining traction. It offers a practical solution for those dealing with rising temperatures. Read more here
Handheld nitrate meters that hold calibration
Members are evaluating different handheld nitrate meters, focusing on models that maintain calibration effectively. This is key for those needing precise measurements. Read more here
Earliest greenhouse biocontrol — year and species
A historical dive into the origins of biocontrol in greenhouses, covering the first species used and their impact. It’s an insightful topic for history buffs and practitioners alike. Read more here
Seeking advanced training in VPD and PID tuning
Looking to refine skills in VPD and PID tuning? A thread is dedicated to advanced training resources for optimizing plant growth conditions. Read more here
Sourcing diverse ornamental germplasm
Explore avenues for sourcing diverse ornamental germplasm, crucial for breeding programs and biodiversity. Read more here
Thank you for being an integral part of our community. Your participation and expertise keep our discussions both lively and informative. Looking forward to another fruitful week.
If heat’s the target, replace the sunniest 1 m of lawn with a mixed native hedge, mulch 5–7 cm, and run a single drip line; you’ll usually see 2–4°C cooler afternoon surface temps than turf — easy to verify with a cheap IR thermometer. Where width’s tight, tall bunchgrasses give similar cooling without hedge bulk. Anyone tried “hedges as a sustainable alternative” using hawthorn with an understory of Carex, or is a narrow Ilex working better?
On those small greening grants, west edge over lawn every time: shade the paving/building and you cut the afternoon ‘radiant slap’ more than a central strip in my tests. Plant bareroot mixed native whips now with a 13 mm drip (2 L/h, 30–40 cm spacing) and underplant with creeping thyme instead of bare mulch to hold another degree. @grace_l89 small caveat: keep porosity about 40% and height under about 1.2 m so you don’t kill night airflow.
I’ve had better afternoon temps by stacking a 60–80 cm hedge strip with a dense groundcover on the west boundary — more leaf area, more evapotranspiration than lawn, and it kills that “radiant slap” @grace_l89 mentioned. On a tight grant, put the money into a simple 13 mm drip loop and 5 cm woodchip; run 20–30 min late-afternoon for the first two summers and verify with a $20 IR temp gun. If water’s tight, go wire trellis + fast deciduous vine for two seasons, then underplant — anyone have surface temp numbers comparing that to a low hedge?
In my last courtyard retrofit, I got cooler 3 pm wall temps by setting the native hedge 40 cm off the west wall and clipping for about “30% porosity”; a solid hedge there trapped heat on still days. Compared with lawn, the wall shed heat faster into the evening with that setup. Would love to see wall-vs-air temps from others, @mira_garden.