Common Ivy

Introduction

Hedera helix, L.

Ivy is an evergreen climbing member of the Araliaceae family. Ivy is an important element in European and Asian woodlands, comprising a large portion of woodland understory, especially in the British Isles. There are several ornamental varieties that are grown for gardeners and it is prized by naturalists for the flowers and fruits it produces late in the autumn; a useful foodstuff and refuge for invertebrates and birds.

Ivy has aerial roots that have matted pads that enable the plant to cling to the substrate and climb to heights of up to 30 metres to the canopy. It uses trees and buildings to climb to a great height enabling it to benefit from being in the top of the canopy without the structural investment that other canopy species make. If Ivy is unable to climb it will creep along the ground and not exceed more than 20 cm in height.

Ivy is not directly harmful to trees however the “sail effect” created by an enlarged canopy particularly during the winter when most broadleaved species lose their leaves can make older, veteran trees susceptible to damage. Ivy is unlikely to be a problem in the UK where a suite of natural pests and diseases keep it in check; and its benefits to wildlife far outweigh any damage it may do to the tree that it uses for support. It can however be a problem on structures where it can dry the mortar out and cause physical damage to walls.

Identification

Ivy is an evergreen climber that will scale up to 30 metres using its adventitious root system. Where no vertical surface exists it creeps along the ground. The leaves are alternately arranged on the stem, 50–100 mm long, with a 15–20 mm stem. Ivy has two types of leaves, five-lobed juvenile leaves on creeping and climbing stems, and unlobed adult leaves on fertile flowering stems exposed to full sun, usually high in the canopy of trees or at the top of structures. The flowers are produced from late summer until late autumn, individually small, in 3–5 cm diameter heads, greenish-yellow, and very rich in nectar, an important late autumn food source for bees and other insects. The fruit are purple-black berries 6–8 mm in diameter, ripening in late winter, and are an important food for many birds, though somewhat poisonous to humans.

Cultural Methods Of Control

Ivy does not tolerate being cut back therefore if it is surrounded by an area that is regularly mowed it can be constrained however because of its aerial roots it quite happily grows over and around barriers. It can also be controlled by placing it in a pot suspended away from the floor this will prevent is spreading however placing it into a deep open pot, a method used by gardeners to control certain invasive species from spreading, is not effective with Ivy simply because it will grow over the pot.

Chemical Methods Of Control

Professional Herbicides

Ivy has an exceptionally thick waxy cuticle, which prevents many foliar applied herbicides being very effective. Glyphosate, the active ingredient in Roundup Pro ProVantage can be used and the following notes will aid its efficacy;

To maximise control in areas where an alternative residual weed control is not possible or where re-cropping of the area is planned it may be necessary to use a non-residual, environmentally acceptable herbicide, the following will optimise control with Roundup Pro Biactive.

Foliar Application

  • Wait until the shoots have some new, soft leaf growth in the spring, usually May at the earliest. Over-wintered leaves have tough, thickened wax layers as they are hardened in the cold weather, which are more difficult to penetrate.
  • Apply the highest rate of Roundup Pro Biactive recommended
  • Add up to 2% Mixture B to increase penetration of the cuticle.
  • A weedwiper could also be used where decorative plants are growing intimately with the ivy.
  • Monitor and re-treat the sites as necessary over a period of three years.
  • Cut Stump / Stem Injection Treatment

Where ivy is mature and growing up masonry or trees there may be a woody trunk which can be treated as trees in the dormant season. This method is very effective on ivy.

Application To Mature Ivy

Ivy must be dormant, this usually occurs between November and February, although in some seasons and in the most northern parts of the country this could extend until the end of March.

Cut Stump Method

Application of Roundup Pro Biactive must be made to a fresh cut so that uptake into the phloem is maximised.

Use a paintbrush and apply immediately after cutting. (Uptake is almost immediate from a fresh cut and will be rainfast within 10 minutes. Application to a cut that has partially sealed means absorption is slow and rain within 6 hours will wash some of the product off.)

Chemical Thinning

Neat Roundup Pro Biactive is introduced straight into the phloem through a axe cut into the bark of the ivy leaving the plant intact. A Spot gun with a solid stream nozzle is recommended and it is advisable to make a second cut under the first to catch any surplus herbicide. Work out how many hatchet cuts are needed according to the diameter of the trunk and space them round the girth. e.g. trunk of 20cm diameter requires 2 cuts. Alternatively the concentrate can be introduced through an 8mm drill hole, about 40mm long, aimed slightly downwards and radially towards the centre of the stem.

Domestic Weed Killer

Ivy has an exceptionally thick waxy cuticle, which prevents many foliar applied herbicides being very effective. Glyphosate, the active ingredient in Asteroid Biocare can be used and the following notes will aid its efficacy. Asteroid Biocare is a very effective herbicide that starts to degrade almost as soon as it is applied however it is not selective and will kill any plant it comes into contact with.

To maximise control in areas where an alternative residual weed control is not possible or where re-cropping of the area is planned it may be necessary to use a non-residual, environmentally acceptable herbicide, the following will optimise control with Asteroid Biocare.

Foliar Application

  • Wait until the shoots have some new, soft leaf growth in the spring, usually May at the earliest. Over-wintered leaves have tough, thickened wax layers as they are hardened in the cold weather, which are more difficult to penetrate.
  • Monitor and re-treat the sites as necessary over a period of three years.
ICL image
Campey Turf Care Advert image
John Deere Advert image
Pitchcare Ireland Advertise with us image