Imperata cylindrica rubra
A popular landscaping grass with attractive foliage that is red tinged Japanese Blood Grass with its new red tipped shoots amongst the older foliage is used widely as an ornamental grass. Excellent colour in autumn.
Requiring little care other than removal of overly green sections. Excellent in a container where it adds brilliant colour to garden or courtyard.
HOWEVER, the species itself, Imperata cylindrica is regarded as an invasive weed.
The ‘rubra’ variety is said to not produce seed, and is also said to be less aggressive in its spread.
This is being debated in the USA, where it is thought to be only part sterile…
How to Grow Japanese Blood Grass – Growing Tips
Planted in the right position Japanese Blood Grass is an easy care low maintenance ornamental grass. The red tips from summer through to winter are a standout.
Here are our top tips for growing this colourful grass.
- Position/Light
For the best foliage colour and best growth you need to plant this ornamental grass in full sun in all but the hottest zones where a little shade in the afternoon is recommended.
In a position with too much shade the foliage will revert to green and we suggest using a different grass such as Hakonechloa – Japanese Temple grass in shaded areas. - Soil
A well drained humus rich soil is essential. Wet soggy soils will need to have drainage improved by either raising the garden bed or adding extra drainage material to the soil. We suggest you just avoid these conditions and plant in an appropriate soil or grow this colourful grass in containers. - Planting
Plant at the same depth that the grass was in the container. Single clumps look good so space them at around 3ft(1m) apart.
You can easily dig and divide the clumps once established and this can be done in spring. - Temperature / Climate Zone
Very cold temperatures with long cold winters, frosts and freezes, you may struggle to grow this grass successfully. In tropical zones, again it struggles with very high humidity and excessive moisture. - Fertiliser
In good soil no extra fertiliser will be required.In poor soils, an application of slow release organic fertiliser in spring should be adequate.
When growing in pots, fertilise in spring with that slow release fertiliser and use a liquid fertiliser every 4 weeks.
Japanese blood grass will reach around 50cm in height and is a wonderful red grass, excellent for landscaping but also attractive when grown it pots of containers. It does have a tendency to creep and spread, so maybe consider a root barrier if planting in the garden.
Summary Information
- Botanical Name – Imperata cylindrica ‘rubra’
- Common Names – Japanese Blood Grass, Cogon Grass
- Country of Origin – Japan.
- Climate Zones – Warm Temperate to Mediteranean.
- Position – Full sun to light afternoon shade
- Soil – Tolerates a range of well drained soils and moist soils.Height –To around 1.5 metresSpread – Clumping to 2 – 3 metres.
- Growth Rate – Medium
- Foliage – Mid Green base with red tips..
- Flowers – Seed heads are large and silvery grey.
- Flowering Time – Spring to Summer.
- Frost tolerant – Moderate frosts only.
- Drought tolerant – No
- Root system – The cultivar ‘rubra’ is regarded as non invasive. Any clump that reverts to fully green should be removed.
Landscaping Uses
Feature grass in the border or grown in a container.
Japanese Blood Grass is available for sale from the following nurseries
470 Monbulk-Silvan Road Monbulk VIC 3793
"Guaranteed mail order flowering bulbs, perennials, roses, trees, landscaping plants, garden accessories and community fundraising Austra lia-wide."
www.gardenexpress.com.au