As observed during July 2012

24/7/2012

Red thread on a green carpet

This wet summer has given us lush growth; it has also given ideal climatic conditions for the invasion of Red Thread, Laetisaria fuciformis , a fungal disease of turf that is more prevalent in wet summers.

At an early stage of development the leaf blade of the grass turns red, patches of grass will then brown off. 

There is an increased risk of infection on lawns of low vigour where a nitrogen shortage is evident. For a quick fix an application of Sulphate of Ammonia is one solution to the problem. However we are rather late in the season to go down this path. Applications of excessive nitrogen are never to be recommended and at this stage in the growing season may encourage soft growth which is poor practice for the lead into autumn where a denser sward is ideal. 

Scarify and consider drainage of surface water as more permanent solutions. However even with no treatment the grass will recover and lawns will grow together as our summer dries out. Grass cuttings and debris from scarifying must be composted correctly or the fungal spores may remain viable for another cycle of infection.

17/7/2012

Light up a dark corner

Hydrangea heteromalla is flowering on the lower edge of the Chinese hillside. The large panicles of brilliant white flowers are setting off the canopy under which it grows.

 A mixture of the sterile and fertile flowers makes up the terminal floral cluster. The sterile flowers each have four pure white sepals these are on the outer edge surrounding the smaller fertile flowers.

A deciduous shrub reaching five metres within its native distribution of northern and western China. Found on mountain slopes at 2400 – 3400m. The leaves are distinctively veined and are attached to the shoot with a purple leaf stalk.

10/7/2012

Ground cover potential

Tight growing and compact this Ophiopogon intermedius with its linear grass like foliage is a good
ground cover plant with high drought tolerance. Once planted it will take
several seasons to settle and establish. Through good cultivation the clumps
will fuse together providing an impenetrable barrier to other vegetation
seeking to colonise the area. Fresh new growth shoots up vertically, the plant
splits easily so a good gardener will rapidly increase the size of the
colony.  

With a wide distribution through the Himalayas to Indochina this species colonises forest margins. It
produces plentiful flower spikes with pearly white buds that open to a clear
pure white.

Rainfall facts from Bruce who records the weather at RBGE: The total rainfall for June 2012 was 142.8mm. This is almost
twice last year’s 76.6mm.For June 2010 we received 41.5mm and for June 2009, 32.1mm.You have to go back as far as 1997 to find an equivalent
rainfall of 148.5mm. Interestingly that very wet June was preceded by the very dry June (only 13mm) of 1996.

2/7/2012

Bracts not petals

Cornus capitata has a wide range through SW China and the Himalayas.
This evergreen, or in very cold winters semi evergreen, is found at lower
elevations (around 2300m) on the edge of mixed woodland. Planted at the western
edge of the Chinese hillside, here at RBGE, is a mature specimen, covered in
flower. Here it displays a showy presence of an unusual nature.

Four petal like bracts, pointed, creamy white in colour,
surround the true flowers. These insignificant individuals are tightly packed
in a raised dome and later are followed by red fruit in season.

 

For previous years' highlights during this month, see the July Garden Highlights Archive page.  

Back to Top