R2103 Plant Disorders. Frost damage and Fasciation.

Introduction

As well as pests and diseases there is another way that plant health can suffer and this comes under the heading of Plant Disorders. Plant disorder can be defined as follows:

Plant disorder = plant health problem caused, not by a pathogen, but by some problem in the environment. Caused by a non living factor.

Although disorders are caused by non living factors they can be exacerbated by the gardener who grows plants in the greenhouse and does not pay attention to watering, shading, monitoring and controlling temperature, and watering regime. There are many ways the gardener can prevent (or as the syllabus says 'ameliorate') disorders but the actual symptoms are mostly caused by poor environmental conditions.

Examples of disorders which are outlined in the RHS syllabus:

Frost

Shade

Drought

Water logging

High / Low temperatures

Soil pH including the symptoms of Lime induced chlorosis

Fasciation

Rose Balling

In this blog I am focusing on frost and fasciation disorders.

FROST

https://www.rhs.org.uk/advice/profile?pid=470

Profile of starwberry black eye

Frost Damage Potatoes (A late frost in May which was unexpected) This could have been prevented by covering with fleece.

Gunnera manicata leaves are tender and will suffer frost damage unless protected. This means the leaves are unsightly all Summer if not removed.

The late unexpected frost in May also damaged the young soft growing tips of the variegated Holly

FASCIATION

https://www.rhs.org.uk/Plants/131417/Dryopteris-affinis-Cristata/Details

profile of crested fern

Fasciated stems of Forsythia x intermedia are flattened and appear as if many stems are fused together.

Fasciated Cosmos flower with the typical oval shape compared to the usual round centre.

Fasciated Sempervivum abovecompared to a 'normal' Sempervivum below. They are different cultivars but the photo shows the difference in shape.

Saguaro cactus (Carnegeia gigantea) in Arizona. Fasciated saguaro in centre with 'normal ' cacti either side.

Pictured above is a species of Veronicastrum in my garden. There is a species of Veronicastrum which is bred as a fasciated variety called Veronicastrum virginicum 'Fascination' However this picture is not this variety as this one is smaller and darker in colour. (Note to self write the name down when you buy new plants!!) It does show that Veronicastrum are generally prone to fasciation disorder.

Here is the link to Veronicastrum virginicum 'Fascination' (Note the extra n, it is Veronicastrum virginicum Fascination not fasciation)

https://www.rhs.org.uk/Plants/109381/i-Veronicastrum-virginicum-i-Fascination/Details

Further Reading

If you want to read more about the fascinating world of fasciation I found this great link:

https://tentativeplantscientist.wordpress.com/2014/08/11/fasciation/