SFI Action CIPM2: Flower-Rich Grass Margins, Blocks and In-Field Strips — A Practical Guide

CIPM2 is one of the most ecologically versatile actions in the SFI26 offer. Whether you are looking to soften field margins, create in-field biodiversity strips, or establish permanent wildflower blocks on your arable or mixed farm, this action delivers real habitat value while remaining practically manageable within a working farming system.

With Window 1 opening from 30 June 2026 for small farms and those without an existing ELM agreement, the time to prepare is now. This guide walks through the seed mix requirements, sowing approach, and management needed to get CIPM2 strips and blocks established well and keep them performing year after year.

What Is SFI Action CIPM2?

CIPM2 — Flower-Rich Grass Margins, Blocks or In-Field Strips — requires the establishment and maintenance of a well-established grass margin or block containing a range of flowering plants that provide pollen and nectar through Summer and into early Autumn.

Unlike CAHL1, which is a pure wildflower mix, CIPM2 permits and requires a grass component. The Defra specification sets:

• A minimum of 4 grass species making up no more than 90% of the total seed mix
• A minimum of 10 wildflower species
• No individual wildflower species exceeding 25% of the total wildflower component by weight

CIPM2 is a rotational or static action with a 3-year duration. Like CAHL1, it is subject to the 25% combined area cap in SFI26, applied across the same group of ten area-limited actions.

Why CIPM2 Works Well on Arable and Mixed Farms

The inclusion of grasses makes CIPM2 suitable for a wider range of field-edge situations than a pure wildflower mix. A grass-forb sward is more resilient to trampling and spray drift on field margins, establishes more reliably on heavier or more fertile soils, and provides structural habitat that supports invertebrates, ground-nesting birds, and small mammals as well as pollinators.

Well-designed CIPM2 strips also work as part of an integrated pest management strategy — beneficial predators, including parasitic wasps, ground beetles, and hoverfly larvae, use flower-rich margins as overwintering and foraging habitat, reducing reliance on insecticides in adjacent crops.

Choosing the Right CIPM2 Seed Mix

The specification requires 4 grass species and 10 wildflowers, but a good CIPM2 mix will typically carry considerably more than this minimum. The grass species should be fine-leaved and non-aggressive — the aim is a low-growing, open sward that allows wildflowers to establish and persist rather than being crowded out.

Grass Species to Include

• Common Bent (Agrostis capillaris) — fine-leaved, low-growing, compatible with wildflowers
• Crested Dogstail (Cynosurus cristatus) — a traditional meadow grass, slow-spreading, wildlife value
• Sheep’s Fescue (Festuca ovina) — suited to drier, less fertile margins
• Red Fescue (Festuca rubra) — excellent for semi-shaded margins and hedgerow edges
• Yellow Oat-grass (Trisetum flavescens) — good on chalk or limestone-based soils

Avoid rye-grass (Lolium perenne) and Cocksfoot (Dactylis glomerata) — both are too competitive and will swamp the wildflower component within a couple of seasons.

Wildflower Species to Include

A well-rounded CIPM2 wildflower component typically includes species that provide a range of flower structure and a long combined flowering season:

• Oxeye Daisy (Leucanthemum vulgare) — long-lasting, highly attractive to hoverflies and beetles
• Common Knapweed (Centaurea nigra) — extended flowering, essential for bumblebees and butterflies
• Birdsfoot Trefoil (Lotus corniculatus) — low-growing legume, key species for several specialist bees
• Meadow Buttercup (Ranunculus acris) — early season, good for early-emerging bees
• Red Clover (Trifolium pratense) — nitrogen-fixing, extended flowering, bumblebee magnet
• Yarrow (Achillea millefolium) — drought-tolerant, very long flowering period
• Wild Marjoram (Origanum vulgare) — exceptional pollinator value, suited to well-drained margins
• Ribwort Plantain (Plantago lanceolata) — wind-pollinated but important for specialist bees and caterpillar food plant

Ground Preparation for CIPM2

The key principle for CIPM2, as for all wildflower-grass mixes, is low soil fertility. On arable field margins this can be a challenge — years of fertiliser application and soil disturbance mean most field edges have significantly higher fertility than an unimproved grassland would. High fertility favours rank grasses and aggressive broadleaved weeds at the expense of the fine-leaved grasses and wildflowers you are trying to establish.

Reducing Soil Fertility Before Sowing

• Do not apply any fertiliser, manure, or soil improver to the area in the season before sowing
• On highly fertile ground, consider a preliminary crop of a fertility-depleting species such as a phacelia or mustard before cultivating for the wildflower mix
• Remove any surface debris, stubble, or dense thatch — bare, fine seedbed is the target
• Use a false seedbed approach where possible — cultivate, allow a flush of annual weeds, then shallow cultivate again before sowing

Seedbed Preparation

Aim for a fine, firm, level seedbed. Avoid deep cultivation before sowing — this brings buried weed seeds to the surface. A shallow pass to 5–8cm depth is enough to create the fine tilth that CIPM2 seed mixes need for reliable germination.

Sowing Windows and Rates for CIPM2

CIPM2 mixes containing both grasses and wildflowers are best sown in late Summer to early Autumn — typically August to the end of September.

Why Autumn Sowing Works Best

Most native wildflower species in a CIPM2 mix benefit from cold stratification over Winter, which triggers germination in Spring. Autumn-sown grass components establish strong root systems before the harder conditions of Winter, giving them a head start on weeds the following Spring. An autumn-sown CIPM2 strip will typically deliver its first flush of wildflower colour in Year 2.

Spring Sowing

Spring sowing (March–May) is possible, particularly for annual-heavy mixes. However, for a mix containing native perennial grasses and wildflowers, spring sowing generally produces a less robust stand in Year 1, with the perennial component taking longer to establish without the Winter stratification period.

Sowing Rates

For an 80/20 grass/wildflower mix, sow at 5g per m² (50kg per hectare). For a higher-wildflower ratio (closer to a 60/40 split), reduce to 3–4g per m². Broadcasting is standard — mix with dry sand at 1:4 to improve distribution. Roll after sowing on firm ground.

Establishment and Year One Management

In the first growing season, CIPM2 strips will typically show a mix of establishing grasses and early-flowering annuals if included in the mix. Perennial wildflowers will often not flower until Year 2.

The critical Year 1 management decision is whether to cut. If the strip develops a dense flush of annual weeds (Fat Hen, Mayweed, Charlock) before the sown species can compete, a single cut to 15cm in early Summer will set back the weeds without killing the rosette-forming wildflowers developing at ground level. Remove the cuttings — do not leave them to rot on the surface.

By Autumn of Year 1, a well-established CIPM2 strip should show good grass coverage and the rosettes of several wildflower species at ground level. If the strip looks sparse, assess whether it is weed competition, poor germination, or soil fertility that is holding it back before deciding on remedial action.

Long-Term Management of CIPM2 Strips and Blocks

An established CIPM2 sward is self-sustaining with light annual management. The aim is to maintain an open, mixed-height sward that prevents any single species from dominating.

• Cut once annually in late Autumn (October–November) after flowering has finished. Remove cuttings to prevent a fertility return to the sward.
• If the grass component is becoming dominant and crowding out wildflowers, scarify or harrow in Autumn to create bare patches for wildflower regeneration from seed.
• Spot treatment of injurious weeds using a weed wiper is permitted. Do not broadcast spray.
• For static CIPM2 areas, check the wildflower component annually. If it is declining, consider introducing plug plants or overseeding bare patches with additional wildflower seed in Autumn.
• For rotational delivery, move the strip or block to a fresh area with a clean seedbed at the start of each new period, following the same preparation and sowing process.

Wildahome Seed Mixes for CIPM2

Our Traditional Wildflower Meadow Mix (80/20 grass/wildflower ratio) is designed precisely for situations like CIPM2 — a balanced sward of fine native grasses and 33 wildflower species that delivers season-long colour and genuine habitat value. Sow at 5g per m² on prepared ground.

On heavier, wetter margins, the Wetland & Pond Mix provides a CIPM2-suitable option for low-lying field edges and drainage channels. For chalky or limestone soils, our Chalk & Limestone Mix brings in specialist species like Horseshoe Vetch (Hippocrepis comosa) and Clustered Bellflower (Campanula glomerata) that thrive on alkaline ground.

All our mixes are grown from British seed at our farms in Devon and Powys. We are happy to advise on mix selection based on your soil type and location — contact us before ordering if you are unsure which mix fits your margins best.