UGR Green Roof Wildflower Seed Mix – 30g

Create a colourful, wildlife-friendly green roof

UGR Green Roof Wildflower Seed Mix is a specially selected blend of British native wildflowers and herbs developed for green roof environments.

The mixture contains no grass seed and includes up to 30 mainly low-to-medium-height species suited to low-depth, low-fertility growing media. Once established, the varied flowers can provide colour and habitat while attracting bees, butterflies and other native pollinating wildlife.

Each 30g pack covers approximately 10m² when sown at the recommended rate of 3g per square metre.

Developed specifically for green roofs

Green roof conditions can be challenging for ordinary planting, with shallow growing media, lower nutrient levels and greater exposure to sun and wind.

This mixture has been selected for those conditions and can be used to establish a biodiverse planted surface on suitable extensive or intensive green roof substrate.

It is ideal for:

• Domestic green roofs
• Sheds and garden rooms
• Extensions and garages
• Commercial roof areas
• Biodiverse extensive green roofs
• Low-fertility wildflower planting
• New green roof systems requiring seed-based planting

A varied native wildflower mixture

The mixture may include the following British native wildflowers and herbs:

• Agrimony – Agrimonia eupatoria
• Bird's-foot trefoil – Lotus corniculatus
• Bladder campion – Silene vulgaris
• Bulbous buttercup – Ranunculus bulbosus
• Common knapweed – Centaurea nigra
• Common poppy – Papaver rhoeas
• Common toadflax – Linaria vulgaris
• Corn chamomile – Anthemis arvensis
• Corn marigold – Glebionis segetum
• Corncockle – Agrostemma githago
• Cornflower – Centaurea cyanus
• Cowslip – Primula veris
• Field forget-me-not – Myosotis arvensis
• Field pansy – Viola arvensis
• Field scabious – Knautia arvensis
• Hoary plantain – Plantago media
• Kidney vetch – Anthyllis vulneraria
• Lady's bedstraw – Galium verum
• Meadow buttercup – Ranunculus acris
• Musk mallow – Malva moschata
• Oxeye daisy – Leucanthemum vulgare
• Perforate St John's wort – Hypericum perforatum
• Ribwort plantain – Plantago lanceolata
• Rough hawkbit – Leontodon hispidus
• Salad burnet – Sanguisorba poterium
• Scentless chamomile – Tripleurospermum inodorum
• Selfheal – Prunella vulgaris
• Viper's bugloss – Echium vulgare
• White campion – Silene latifolia
• Wild marjoram – Origanum vulgare
• Wild mignonette – Reseda lutea

The exact species and proportions can vary according to seed availability, so the mixture should not be represented as having a permanently fixed composition.

Coverage and sowing rate

• Pack size: 30g
• Recommended sowing rate: 3g/m²
• Approximate coverage: 10m²

Measure the area of prepared growing substrate rather than the total roof area. Exclude pebble borders, outlets, perimeter details and any other areas that will not be seeded.

Preparing the growing medium

The seeds must be sown onto a suitable green roof substrate. Before sowing:

1. Complete the waterproofing, drainage and green roof build-up.
2. Add the specified growing substrate.
3. Level the growing medium across the planted area.
4. Rake the surface to a fine tilth.
5. Remove large stones, debris and unwanted plant growth.
6. Ensure the surface is moist but not waterlogged.

The mixture can be used with different growing media. Extensive substrate is particularly suitable for shallow green roof seeding, while a deeper, more fertile intensive substrate may provide slightly improved germination. The datasheet describes extensive substrate depths of approximately 60–200mm and intensive substrate depths of approximately 200–1,000mm.

Sowing the wildflower seeds

1. Sow during spring or autumn wherever possible.
2. Divide the seed into smaller portions to help achieve an even distribution.
3. Scatter the seed evenly across the levelled, finely raked substrate.
4. Sow at approximately 3g per square metre.
5. Leave the seed on the prepared surface rather than mixing it deeply into the growing medium.
6. Water the area lightly after sowing.
7. Keep the substrate sufficiently moist during establishment without allowing it to become waterlogged.

Spring-sown seed may require occasional watering through the summer so that the seed and young plants do not dry out. Watering is best carried out during the morning or evening.

When will the wildflowers appear?

Some growth should normally be visible during the first year, depending on the sowing date, weather, substrate and watering.

Some perennial species require a period of frost and thaw before they germinate successfully. As a result, the roof may produce a stronger or more varied display during its second year.

Wildflower establishment is a gradual natural process rather than an instant planted finish.

Maintaining the wildflower roof

From March onwards, allow the developing vegetation to grow without regular cutting.

After the flowers have finished and the seed heads have dispersed naturally, cut back the vegetation in late autumn and remove the clippings from the roof.

Removing the cut material helps prevent excessive nutrients building up within the growing medium and keeps the area suitable for wildflowers adapted to lower-fertility conditions.

Once the seedlings are established, gradually reduce routine watering, although additional water may still be required during prolonged dry periods.

Complete the perimeter

Pebbles can be used around the perimeter, drainage outlets and roof penetrations to keep vegetation and substrate away from important drainage details — UGR Green Roof Border Pebbles – 20kg Bags.

For a neat separation between the planted area and pebble border, use UGR Aluminium Green Roof Edge Trim – 1m.

Important suitability note

These seeds must be sown onto a suitable prepared green roof substrate. They should not be applied directly to waterproofing, drainage membrane, protection fleece, pebbles or another surface that cannot support plant establishment.

The exact species present, germination rate and finished appearance will vary according to seasonal conditions, seed availability, substrate, moisture and ongoing maintenance.