How to Grow Wildflower Mixes in Australia

The Butterfly Wildflower Mix and the Beneficial Bug Mix blend flowers, many from the daisy family (Asteraceae), such as rudbeckia (Rudbeckia) and calendula (Calendula officinalis). Sown as one patch, they feed butterflies, bees and the hoverflies, lacewings and small wasps that hunt garden pests. Most patches that fail are lost before sowing, in a bed still full of weed seed.

Three mistakes that matter

1. Sowing into a weedy bed. Weed seedlings come up with the flowers and soon outgrow them, because young wildflowers cannot compete. Clear the bed and flush out a crop of weeds before sowing, as set out in Site, soil and setup.
2. Burying the seed. The mixes hold seed of many sizes, and some, such as alyssum, need light to germinate. Seed raked in deep often comes up thin and patchy, so tickle it in lightly, as set out in Sowing Seeds.
3. Letting the surface dry out. Germinating seed and young seedlings sit in the top few millimetres of soil, which a hot, windy day dries first. Keep the surface damp for the first four to six weeks, as set out in Care by growth stage.

When to plant

Sow in spring once the frosts are over, the window both listings give. The hardy annuals in the Beneficial Bug Mix also suit autumn sowing in milder zones, sitting through winter and taking off in spring. A second sowing into bare gaps a few weeks after the first keeps flowers coming.

Avoid sowing in the heat of midsummer unless you can water every day. Where frosts are hard, hold the Butterfly Wildflower Mix until the last frost has passed, as zinnias do not like frost.

Site, soil and setup

Pick an open spot with at least six hours of direct sun, clear of trees and shrubs that would overshadow it. Both listings suggest a garden edge or fence line that can go a little wild. Among other plants, leave a clear patch at least 50 cm across.

Choose a spot that can stay put. The perennials in the Butterfly Wildflower Mix need more than one season, so keep the patch out of vegie beds that are dug and rotated.

What the state weed lists say

A few of the plants the two listings name escape gardens in parts of Australia, and Victoria declares one kind of lavender. The listings rarely name a species, so the table covers weedy species sharing a listed genus or common name, which the mixes may not hold.

A plant regarded as an environmental weed can still be grown, but it can spread into bushland. Near bush, creeks or roadside reserves, cut seed heads before they ripen, and ask your council weed officer which plants are a problem locally.

Sowing Seeds

Scatter the seed by hand straight onto the prepared bed, where the plants will flower.

Choosing a mix

Sowing direct

• Sow about 1 g of seed per square metre, the rate the 25 g pack works to.
• Stir the seed through about 1 kg of dry sand per square metre, so it spreads evenly and shows where it has landed.
• Scatter half the mix walking one way and the other half at right angles.
• Tickle the seed in with your fingers or the back of a rake, so none lies deeper than 5 mm.
• Press the bed down with your feet or a board, then water gently with a fine spray.
• Seedlings usually appear in 8 to 14 days.

Leave the stand dense, thinning only crowded clumps, and over-sow any bare patches with the same mix. Melbourne's city flower meadow was over-sown this way so no gaps were left.

Care by growth stage

Water decides a wildflower patch far more than feeding does, and most of the work falls in the first six weeks. Weeks count from sowing.

If growth stalls in very poor soil, a light dose of controlled release all-purpose granular (NPK around 14-5-10) scratched into the surface can help. Rich feeding is not usually needed and pushes soft growth that aphids favour.

Cutting Back

Cutting through the season keeps the annuals flowering, and one cut at the end of it sets the patch up for the next year.

• Through the season: deadhead faded flowers you have not picked, so the plants keep making buds.
• Self-seeding: where you want the annuals back, let some seed heads ripen and drop their seed first.
• End of season: once flowering winds down in autumn, cut the annuals to about 15 cm and clear the cuttings away.
• Perennials: leave their crowns and roots undisturbed, and never dig the patch over.
• Near bushland: skip self-seeding and cut seed heads before they ripen, as Site, soil and setup explains.
• Milkweed: wear gloves, because its sap is poisonous and can irritate skin and eyes.

Companion planting

A wildflower patch earns its place beside crops that suffer from aphids and caterpillars, because many of the insects it feeds hunt those pests.

Grows well with

• Vegetable beds: adult hoverflies feed on the flowers, and their larvae eat aphids on nearby crops.
• Extra alyssum along the edge: its haze of tiny flowers draws hoverflies and parasitic wasps.
• The Pollinator and Beneficial Insect Mix: a third insect mix, grown as set out in Cover Crop Mixes.

Keep apart

• Kikuyu and other running lawn grasses: their runners creep into the bed, and a spade-cut V edge about 10 cm deep slows them.
• Trees and large shrubs: their shade cuts flowering, as most of these flowers need full sun.

Flowering and Cutting

The first annuals usually open 8 to 14 weeks after sowing, while the perennials in the Butterfly Wildflower Mix spend their first season building roots.

• Pick stems freely for small posies, since regular cutting brings more flowers.
• Leave most blooms on the plants for the insects the patch is there to feed.
• Leave some echinacea heads standing to ripen seed for birds.

Keep leftover seed for follow-up sowings in an airtight, labelled jar in the fridge crisper at about 4°C.

Common problems

Seed washed into one corner. Heavy rain or a hard spray shifts fine seed before it germinates. On slopes or before storms, spread a thin layer of sugar cane mulch and press it down.

Seedlings vanish in the first weeks. Birds, slugs and snails all take young seedlings, and the meadow at the Royal Botanic Garden Sydney was netted for about two months. Use only white, taut, wildlife-safe netting with mesh too small for a finger.

Seedlings topple at soil level. Damping off (a soil-borne fungal disease) pinches stems at the base in crowded, soggy patches; sow thinly and keep the surface damp, not wet. Read more

Few flowers in the first summer. A Butterfly Wildflower Mix patch is mostly perennials, which flower from their second season, as the table in Flowering and Cutting shows.

The patch looks tired by late summer. Many annuals reach the end of their run by then, often with mildew on the old leaves. Cut back and resow as set out in Cutting Back.

Pests and diseases

Slugs and snails matter most while seedlings are small; once the patch flowers, the predators it feeds often keep sap-suckers in check.

Common garden snail (Cornu aspersum) and grey field slug (Deroceras reticulatum). Both feed at night and after rain, leaving silvery slime trails and seedlings chewed to stalks. Read more

Aphids (family Aphididae). Small sap-suckers cluster on soft shoots of calendula, cornflower, zinnia and milkweed, leaving sticky honeydew, until ladybirds and hoverfly larvae move in. Read more

Powdery mildew (Podosphaera, Oidium and related fungi). A white, floury film spreads over the leaves of bee balm, zinnia, calendula and Chinese forget-me-not, mostly in warm, humid weather.

Wanderer butterfly (Danaus plexippus). Its caterpillars feed on milkweed leaves, which is why the Butterfly Wildflower Mix includes milkweed, so leave them to it.

Prevention first

• Water at the base in the morning, so leaves dry before night.
• Clear away the damp hideouts slugs and snails use by day; if seedlings still vanish, scatter iron-based bait at the label rate, never metaldehyde.
• Hose aphids off shoot tips with a firm jet, going gently on seedlings.
• Avoid broad-spectrum insecticides; pyrethrum harms bees, so if you use it, spray late in the day away from open flowers.

Tips

1. Each year, sow a strip of the Beneficial Bug Mix along the front of an established Butterfly Wildflower Mix patch. It adds quick colour without disturbing the perennials.
2. Grow both mixes, so the quick annuals flower while the perennials establish. A hungry gap with nothing in flower sends beneficial insects elsewhere.
3. Leave a few hollow perennial stems standing over winter, because native bees nest in them.

Due to quarantine restrictions and our shipping policy, we cannot send the Butterfly Wildflower Mix or the Beneficial Bug Mix to Western Australia or Tasmania.