Understanding Wildflower Seed Mixes

Wildflower seed mixes are an alluring concept. You may encounter these in a seed catalog, a garden center, or as a giveaway. Pictures often depict flowers in a variety of colors and shapes, blooming all at once. Before you plant a wildflower mix, consider the following.

What is a wildflower versus a native plant?

Not all wildflowers are native plants. Though there is no technical definition for a wildflower, it is generally thought of as a plant that naturalizes easily. Think of common roadside plants such as Queen Anne's lace and chicory, which are not native to North America. Unless a wildflower seed mix is specifically labeled as native to your region, it will contain non-native plants. I examined a number of wildflower seed mixes and found the proportions were roughly half native and half non-native plants.

How to select a wildflower seed mix

Look for a seed mix that is formulated for your planting site. Seed mixes exist specifically for sun, shade, riparian areas, dry meadows, woodlands, and other conditions.  Many are designated as pollinator and bird-friendly. Choose a mix designated for your garden's USDA Plant Hardiness Zone. If you want only native plants, ensure the mix is labeled as such.

Where to plant wildflower mixes

A mixture of seeds will take some time to get established, so avoid planting it in a featured part of your landscape. It will not outcompete weeds or turfgrass, so you must eliminate those to create a clean slate for planting seeds. To convert an area of lawn or weeds for a wildflower seed mix, consider smothering the current vegetation by covering it with cardboard or newspaper and then a layer of organic material.  It's best to do this in late summer to plant in the following season. Instructions are in the article Create New Garden Beds with Sheet Composting and Sheet Mulching.

Words of caution

• Wildflower seed mixes usually contain both annuals and perennials unless indicated otherwise. Annuals will be most visible in the first year and may or may not self-seed in subsequent years. Perennials in the mix may not germinate until they have undergone a cold period (called stratification).
• Annuals in the mix may bloom all season, but perennials will not. Each type of perennial will have a bloom period of several weeks. Bloom periods may be staggered, but no perennial will bloom all season.
• Many who have tried wildflower mixes report that one variety of plants takes over after the first year or two.
• Be sure to check what specific plants are in the seed mix. The mix may contain weeds or even invasive species. Some sellers state that their mix does not contain invasive plants, but suggest that you check with your local extension office to make sure.
• Seed mixes should include botanical names so that you are sure what plants you are getting.
• Be especially cautious of seed mixes that are not labeled. You might receive these as wedding favors or embedded in whimsical paper shapes. Planting these in a container may be prudent, just to see what comes up.
• Learn to recognize the plants in the mix so that you will notice weeds that creep into the planting area. It is important to be able to recognize common weeds in your area.
• Though it may take more time, money, and effort, one option for those who want a wildflower area is to choose a carefully planned mix of individual potted plants and/or seed packets that contain only one plant.

Common plants included in wildflower mixes

The following is a list of plants often contained in wildflower mixes, including information on whether they are grown as annuals or perennials in Pennsylvania, whether they are native or not, and their typical bloom color.

• Black-eyed Susan (Rudbeckia hirta) – perennial, native, yellow
• Butterfly milkweed or butterfly weed (Asclepias tuberosa) – perennial, native, orange
• Chinese forget-me-not (Cynoglossum amabile) – annual, non-native, blue
• Coreopsis or tickseed (Coreopsis lanceolata or Coreopsis tinctoria) – perennial, native, yellow
• Flax (Linum spp.) – annual and perennial varieties, non-native, blue
• Indian blanket (Gaillardia pulchella) – annual, native, yellow to red
• Poppy, Icelandic (Papaver nudicaule) – annual or short-lived perennial, non-native, white, yellow, orange, salmon
• Prairie coneflower (Ratibida columnifera) – perennial, native to central and western North America, yellow to red-brown
• Purple coneflower (Echinacea purpurea) – perennial, native, dark pink
• Siberian wallflower (Cheiranthus allionii) – biennial or perennial, non-native, orange
• Shasta daisy (Leucanthemum × superbum) – perennial, non-native, white
• Sweet alyssum (Lobularia maritima) – annual, non-native, white to purple
• Sweet William (Dianthus barbatus) – annual or short-lived perennial, non-native, white, pink, red

If you are considering planting a wildflower mix, consult the Garden Hotline of your county Master Gardener program.  Though they cannot recommend a specific seed company, they can help you evaluate a wildflower mix or help you choose one that is appropriate for your garden.