How to build a garden for monarch butterflies

Monarch butterflies are well known and loved. These butterflies inform our scientific literacy from a young age as we study metamorphosis and their unique relationship with milkweed (their host plant). I always look forward to seeing their beauty each and every season as they migrate north from their overwintering grounds in northern Mexico and fly throughout our region of Central Kansas before returning south later in the year.

The annual monarch census has shown a trend of declines in the monarch butterfly population for many years which is why it is important that we understand how best to provide habitat in our local gardens to help them survive and thrive.

Monarch populations are in decline

Reasons for decline

Primary reasons for monarch butterfly decline include the loss of stems of milkweed and the loss of habitat in general due to urbanization and land use changes. Milkweed is the host plant for the monarch butterfly and without it monarch butterflies have no way to reproduce and provide food for their larvae (caterpillars).

It is estimated that an additional 1.8 billion stems of milkweed are needed to conserve our monarch butterflies!

Monarch garden structure

New research is providing some great information on how we can best build our monarch butterfly gardens in our backyards and home landscapes.

Research done at the University of Kentucky has discovered that monarchs will use and thrive in even small gardens that are designed with a few key things in mind.

Milkweed planted on the exterior of the butterfly garden

First, monarchs prefer an easy to find and accessible milkweed plant. When milkweed was planted at the perimeter (edge) of the monarch butterfly garden, research found that it supported 2.5 to 4 times more monarchs.

The image shows an example. The milkweed (m) is planted in clumps on the exterior of the butterfly garden where it is easy to find. Monarchs use visual cues such as leaf shape to locate milkweed and when milkweed is planted on the exterior of the garden it was much more easily found by the butterflies. The nectar plants can be intermixed as desired and planted inside the milkweed.

Isolated milkweed plants are colonized by monarchs much more readily than milkweed that is intermixed with many other types of plants. In fact, it was even better to plant milkweed in individual clumps on the edge of the garden and set them off with mulch.

Milkweed planted on the edge of the Monarch Butterfly Garden and set off with mulch

The research also discovered that monarch butterfly gardens that were placed in an area with open and easy north/south access were more attractive to the butterflies. When possible, plant monarch gardens in a way that allow easy and unobstructed north/south access since this is their natural migration path.

Key points:

  1. Monarchs will use even very small gardens
  2. Avoid ‘hiding’ milkweed among other plants
  3. Plant gardens where there is easy north/south access to incoming butterflies
  4. Isolated and taller varieties of milkweed plants are preferred by monarch butterflies, set them off with mulch
  5. Plant milkweeds on exterior of gardens
  6. Plant several species of milkweed native to our region but avoid using tropical milkweed in Kansas. When native milkweed stops blooming, it is a cue for the monarch to migrate. Since tropical milkweed blooms much later than our native milkweeds it can interfere with the cue monarchs rely on to migrate at the proper time.

Other monarch butterfly garden components

Don’t forget other key ways to make butterflies feel at home in your garden.

Nectar is the fuel for adult butterflies and every monarch garden should include a variety of nectar producing flowers that bloom throughout the season. The color, as well as the shape, of a flower’s blooms attracts butterflies. While a wide variety of color will attract a greater variety of butterflies, it’s also important to plant your flowers in masses using three or more plants of one variety but remember to keep the milkweed on the perimeter. Here are some examples of plants that can provide nectar.

Aster (Aster)
Bee balm (Monarda)
Black-eyed Susan (Rudbeckia)
Blazing star/gayfeather (Liatris)
Catmint (Nepeta)
Coneflower (Echinacea purpurea)
Coreopsis (Coreopsis)
Goldenrod (Solidago)
Joe Pye weed (Eupatorium)
Milkweed (Asclepias)
Phlox (Phlox paniculata)
Pincushion flower (Scabiosa)
Sedum, tall varieties (Sedum)
Yarrow (Achillea)
Alyssum (Lobularia)
Globe amaranth (Gomphrena)
Heliotrope (Heliotropum arborescens)
Verbena (Verbena. bonariensis)
Pentas (Pentas lanceolata)
Cosmos (Cosmos bipinnatus)
French marigold (Tagetes patula)
Lantana (Lantana camara)
Cosmos (Cosmos sulphurus)
Sneezeweed (Helenium amarum) ‘Dakota Gold’
Salvia (various)
Zinnia (Zinnia elegans)
Lilac (Syringa)
Mock orange (Philadelphus)
Butterfly bush (Buddleia)
Buttonbush (Cephalanthus)
Abelia (Abelia)
Blue spirea (Caryopteris)
Spirea (Spirea)
Chives (Allium schoenoprasum)
Dill (Anethum graveolens)
Lavender (Lavandula)
Marjoram (Origanum majorana)
Oregano (Origanum vulgare)
Sage (Salvia)
Thyme (Thymus)
Fennel (Foeniculum dulce)

Water or a ‘puddling’ space is beneficial to monarch butterflies. Provide a “puddling” space by burying a shallow container of sand and keeping it moist. The butterflies will congregate on damp sand to extract needed salts and minerals.

Add a few light-colored stones protected from the wind on which the cold-blooded butterflies can bask in the sun.

Avoid pesticide use. The chemicals that kill undesirable insects will also kill butterflies and their caterpillars.

Deadhead spent blossoms. Not only will this practice encourage more blooms, it also helps control plants that can become invasive by removing seed heads.