Habitat for butterflies

I delight in the butterflies that flit around my garden.  They add beauty and can be encouraged to be regular guests in any garden if you design it, or at least part of it, for them.  To demonstrate creating a butterfly friendly garden in my show display I am using nectar rich flowers and have giant metal butterflies flying above the garden as well as a butterfly silhouette and a butterfly wall designed for talking selfies.

Decline of butterflies

There are more than 40 butterflies in the Adelaide Region, with twenty commonly seen in urban gardens.  Despite this most adults would say there are less butterflies around than there were when they were a child.  While this may possibly due to the fact that they were more observant when they were children, there are many factors that have contributed to an overall decline in butterflies.  The use of chemical pesticides and herbicides has a big impact on butterflies and it is ironic that gardeners love butterflies and yet often hate caterpillars.  They forget that you cannot have butterflies without caterpillars, and if you want to attract butterflies back into their gardens it is necessary to accept some leaf chewing and damage for a greater benefit.

Two plant requirements

There are two types of plants you need in a ‘Habitat’ garden to attract butterflies – nectar-rich flowering plants for the adult butterflies and the correct food plants for their caterpillars.  You must have food available in spring, summer and autumn and choose a range of plants that flower through these seasons.  Butterflies love colourful flowers and those with daisy or pea flower forms, preferably single rather than double flowers, as they are easier to get nectar from.

While butterflies can use nectar from many different types of flowering plants as their source of energy, their caterpillars require specific food plants.  Female butterflies will only lay their eggs on these plants and therefore will only breed if the specific caterpillar food plant is present.  It is necessary to accept the fact that these plants will be subject to a certain amount of leaf chewing and damage, and obviously the use of garden chemicals must be avoided.

Food and habitat plants

A great way to attract native butterflies is to grow a wide variety of locally native plants ranging from trees and shrubs, down to grasses, groundcovers and climbers.  There are a number of exotic plants that they also love including as Butterfly bushes (Buddleja species), Ageratum, Veronicas (Hebe species) and Cherry pie (Heliotropium arborescens).  Some caterpillar food plants are actually weeds, such as cape weed and stinging nettles.  You may choose to allow a controlled patch of these weeds to exist in your garden where they cannot cause any harm by spreading into the greater environment.

Below is a list of five native butterflies and their food sources.

1. Australian Painted Lady Butterfly – Everlasting daisies such as the native Chrysocephalum species, as well as weed species such as cape weed.
2. Meadow Argus Butterfly – Goodenia species, Fan flowers (Scaevola sp.), or snapdragon.
3. Australian Admiral Butterfly – Stinging nettles (Urtica species) and baby’s tears.
4. Two Spotted Line Blue – wattles (Acacia species).
5. Common Grass Blue – herbs and low bushes with pea flowers such as native lilac (Hardenbergia species), Australia indigo (Indigofera australis), Bush-pea (Pultenaea species), clovers and peas and beans in the vegie patch.

Another common butterfly in Adelaide gardens is the Monarch or Wanderer butterfly.  This is not a native butterfly and arrived from North America in the 1870s but they are still a delight in the garden.  They breed on cotton bush or milkweed species which have a toxic milky sap and which can become weedy.  I grow the swan plant (Asclepias fruticosus) as the caterpillar food source and monitor it so it does not become a weed.

By learning how to identify butterflies such as these and their larvae, you can distinguish between welcome guests and those that are not and need removal, such as cabbage white butterflies which devour the brassicas in our vegie patches, woolly bears, and looper caterpillars.

Other key factors for a butterfly garden apart from appropriate plant selection are:

1. Warmth – There are two aspects to this requirement.  Butterflies are cold blooded and need to warm up in the sun before they can take flight.  As a result they are most active from mid-morning to mid-afternoon so locate your butterfly food plants where they get sun during this period as butterflies rarely will feed in the shade.  Butterflies also use the sun for orientation.  They love to rest and sun themselves to warm up, basking on paved paths or flat stones positioned in the sun yet protected from wind.  In extremely hot weather, they will retreat to cooler shadier places for the heat of the day.
2. Shelter from the wind – This is important at butterfly wings can be damaged by strong winds.  By using a range of butterfly attracting plants of different heights you can use the taller varieties as wind breaks.
3. Water – While gardeners often think about having water bowls for birds, they often forget about insects such as butterflies and bees.  If you have not got a fish or frog pond, leave shallow bowls of water out for these smaller creatures and add some stones, sticks or branches to act as landing platforms.
4. Plant diversity – The current minimalistic landscaping style uses mass plantings of minimal plant varieties and this does not provide enough nor the right sort food plants for butterflies.  Butterflies are seen on warm days in spring summer and autumn so make sure that you have a range of plants which are flowering during this period as well as the rest of the year.
5. Leave things a little wild – Butterflies are likely to visit your garden, and perhaps even stay and breed if you maintain some wild or informal areas such as is found in a cottage style garden.  An intensely-maintained, manicured garden is inhospitable to wildlife because it is constantly being mowed, pruned and tidied.  Many native butterflies and moths lay their larvae on native grasses and the caterpillars need to feed on these plants.  Mowing, slashing or spraying these grasses will destroy the caterpillars.

Accept a little damage

Not only does butterfly gardening mean setting aside a part of your garden for its wildlife value, but it also means accepting some caterpillar damage for a greater purpose.  Gardeners can make a huge difference to urban biodiversity by creating a butterfly garden in their backyards.

More information

For more information read Attracting Butterflies to your Garden – What to grow and Conserve in the Adelaide Region by Hunt, Grund, Keane & Forrest.  The Butterfly Conservation South Australia Inc group has a great website and interesting meetings.  Visit  http://butterflyconservationsa.net.au/