Planting Solar Farms in the South Island

Large-scale solar is arriving in Te Waipounamu, the South Island, with several projects already consented and many more on the drawing board. While the focus is naturally on generating renewable energy, the way these sites are planted has a big influence on their environmental, social and visual success.

Planting isn’t just about “tidying up” a solar farm. Well-designed planting can soften views from neighbouring properties, manage dust and erosion, treat stormwater, and restore ecological function. In fact, planting is often — if not always — a condition of consent, with requirements for screening, ecological enhancement or wetland restoration built into project approvals.

At Riverside Horticulture we haven’t yet supplied to a solar project — but we’ve grown and delivered hundreds of thousands of plants for major farm, roading and restoration jobs across the South Island. The lessons are directly transferrable: know the conditions of the site, plan early, and get the right species in the ground at the right time.

Why planting matters for solar farms

Every solar project comes with different requirements, but there are common themes across the South Island:

• Consent compliance: Most solar farm consents stipulate planting conditions. These often include minimum heights, coverage timelines, or the use of eco-sourced natives for ecological restoration. Planting isn’t optional — it’s part of meeting regulatory obligations.

• Screening and amenity: Boundary planting reduces visual impact for neighbours and road users. Consents often specify layered, multi-species planting rather than a single hedge.

• Soil stability and dust control: Natives stabilise soil along boundaries and tracks, cutting erosion and dust on dry, windy sites.

• Water management: Wetland and swale planting slows and filters runoff, helping to meet stormwater treatment requirements while supporting biodiversity.

• Ecological value: Even small sites can be designed to include native corridors, bird food sources, or lizard habitat. Developers are increasingly required to show biodiversity gains alongside renewable generation.

Design considerations for planting inside and around solar arrays

Planting within solar farms has unique constraints compared to farms, roading, or wetlands:

• Height control: Inside the array, planting must remain low enough not to shade panels. That means sticking with native groundcovers, tussocks and small hebes that stay naturally below panel height.

• Perimeter planting: Taller natives can be used at the boundaries to provide screening, shelter, and a softer edge. Here, species like kānuka, pittosporums, coprosmas and ribbonwood work well depending on the region.

• Wet and low-lying areas: Many solar farms require swales, basins or constructed wetlands for stormwater treatment. These are best planted with sedges, rushes, flax and smaller coprosmas to filter water and provide habitat.

• Maintenance access: Paths, cable routes and inverter pads all need to be kept clear. Planting design should allow for vehicle and mowing access where required, with layouts that reduce the need for ongoing interference.

• Provenance and eco-sourcing: In some regions, eco-sourced seed is a condition of consent. This requires early planning with a nursery partner to collect, grow and deliver the right provenance at scale.

Region-specific planting palettes

Conditions in the South Island vary widely — what thrives on the Canterbury Plains may struggle in Southland. Some typical plant groupings include:

• Canterbury Plains (frost, summer-dry, wind, stony soils)

  • Perimeter: kānuka (Kunzea robusta), ribbonwood (Plagianthus regius), lacebark (Hoheria sexstylosa), korokio (Corokia cotoneaster), coprosmas.

  • Within array: silver tussock (Poa cita), low hebes, Muehlenbeckia axillaris.

  • Swales/wet spots: sedges (Carex virgata, Carex secta), rushes (Juncus edgariae), flax (Phormium tenax).

• Otago (continental climate, severe frosts, dry soils)

  • Perimeter: kānuka, mānuka (Leptospermum scoparium), olearia, pittosporum, coprosmas.

  • Within array: silver tussock, Chionochloa rubra, raoulia mats.

  • Wetlands: Carex coriacea, Juncus gregiflorus, Apodasmia similis (coastal).

• Southland (cool, windy, higher rainfall, clay soils)

  • Perimeter: olearia species, coprosmas, hebes, pittosporums, lacebarks.

  • Within array: Carex testacea, native grasses, Blechnum penna-marina (in shade).

  • Wetlands: sedges, flax, rushes, Coprosma tenuicaulis.

• Marlborough & coastal North Canterbury (salt, drought, wind)

  • Perimeter: taupata (Griselinia littoralis), coastal olearia, coprosmas, cabbage trees (Cordyline australis), Muehlenbeckia astonii.

  • Within array: sand binders like Ficinia spiralis, Austrofestuca littoralis.

Practical details: spacing, grades and maintenance

Getting the numbers right matters — underestimating plants can delay compliance, while overestimating adds unnecessary cost. Some useful rules of thumb:

• Boundary planting: Double or triple rows at 1–1.5 m spacing, using PB3–PB5 grades for quicker establishment.

• Inside the array: Low natives spaced 0.6–1.2 m depending on species.

• Wetlands: Sedges and rushes at 0.6–1.0 m; flax at 1.2–1.5 m.

• Planting window: Autumn through early spring is ideal in most South Island regions.

• Establishment care: Mulching, irrigation (where required), and regular weed control are critical in the first two seasons. Allow for 5–10% replacements after year one.

How Riverside can help

For developers and contractors, the risk isn’t whether planting will be required — it’s how to deliver it successfully. That’s where Riverside comes in:

• Contract growing: We lock in provenance and species early, ensuring plants are the right size, grade and numbers when needed.

• Regional expertise: We’ve grown for Canterbury, Otago, Southland and Marlborough conditions and know what thrives where.

• Scale and logistics: From 10,000 to 300,000+ plants, we can stage deliveries to match your construction programme.

• Traceability: Batch and eco-source records supplied for compliance and reporting.

• Support: Guidance on species selection, planting layouts, and aftercare planning to reduce failure rates.

A new opportunity for solar and ecology

South Island solar farms are more than power stations — they’re new landscapes that communities will live with for decades. Planting them well means better biodiversity, stronger community acceptance, and a smoother consenting process.

If you’re planning or designing a solar project, talk to us early. With the right plants, grown to spec, we can help ensure your site produces clean energy and lasting ecological value for generations.