Brass buttons is a unique New Zealand perennial that can adapt easily to a variety of climates. At only 1/2-2 inches high, it gives gardeners an alternative groundcover plant to add interest to terrariums, fairy gardens, and flowerbeds. It's also used as a turf substitute in mild climates, as well as a filler between paving stones, as it tolerates light foot traffic. The purple-gray and green ferny foliage is ornamental on its own, but the contrasting blooms of yellow daisy-like discs are the icing on the cake and give the plant its common name.
Brass buttons can be planted in the spring or fall, generally from potted nursery starts or root divisions. Its rhizomes spread quickly to form dense mats, and it is listed as somewhat invasive in parts of California.
|Common Name||Brass buttons, buttonweed, golden buttons|
|Botanical Name||Leptinella squalida, formerly known as Cotula squalida|
|Plant Type||Perennial, groundcover|
|Mature Size||1/2-2 in. tall; 8-18 in. wide|
|Hardiness Zones||4-10 (USDA)|
|Native Area||New Zealand|
Brass Buttons Care
Brass buttons plant is appealing to beginning gardeners, because it tolerates a wide variety of light and soil situations. However, it will do best in medium-moisture, well-drained soils, and is not fond of dry conditions. Because it spreads quickly, space brass buttons plants 9 to 12 inches apart to give them space to fill in. Given room, they will spread almost indefinitely. In zones 9-10, brass buttons may be evergreen year-round, but in colder climates it will die back, then quickly restore to full green groundcover by late spring.
Over time, as the soil becomes compacted, a colony may lose its vigor and die back. This is the signal to dig up the area, loosen the soil with organic material, and replant the divisions to restore the groundcover.
In the cool climate of New Zealand, brass button plants thrive in the sun, but in areas with hot summers, brass buttons needs afternoon shade. In fact, brass buttons can grow in full shade, although flowers will be sparse.
Brass buttons plants have shallow roots and need light, loose soil that has been well-worked before planting. Heavy soils or clay will slow down the plant's growth, limiting its ability to act as a ground cover. If your landscape has compacted soil, amend generously with compost or leaf mold before planting. Brass buttons plants prefer an acidic soil pH (5.5-6.8).
In its native habitat, brass buttons plant grows in damp areas. Keep your plants consistently moist to get the best color and plant health, but don't overwater, or root rot can set in. Mulch for the winter to keep roots moist.
Temperature and Humidity
The best climate for growing brass buttons plants is cool and drizzly, like your typical spring day in Seattle or London. But this kind of climate isn't widespread, so it's fortunate that brass buttons plants are tolerant of a wide variety of growing conditions. In hot, dry areas, help plants cope by giving them a shadier locale and an occasional misting.
When you provide the right kind of soil, fertilizing brass buttons plants is unnecessary. In areas with lean soils, an occasional side dressing of compost will be enough to enrich the plants.
Types of Brass Button
Besides the common Leptinella squalida with light green, evergreen foliage, there are a few other types of brass button plant you can grow.
- 'Platt's Black': Named after Jane Platt, a gardener who discovered the plant in her landscape, this variety has dark, almost black foliage with pale green leaf tips.
- Leptinella gruveri: Known commonly as miniature brass buttons, mini fairy fern, or dwarf New Zealand brass buttons, this plant has tiny greenish flowers and is often used as a grass alternative because of its consistent color.
- Leptinella minor: Also named 'Alpine brass buttons', these tiny ferns have deep green and bronze tinges and only grow about an inch tall into a deep carpet that also subs as a lawn.
Because of its short stature, deadheading isn't necessary for brass buttons plants. If you grow the plant as a lawn alternative, you can mow it at the end of summer to tidy the plants.
Propagating Brass Buttons
It's extremely easy to propagate brass buttons, as the plants spread vigorously by rhizomes when growing conditions are ideal. Spring is the best time for propagating brass buttons. Follow these quick and simple steps:
- Dig up and divide a patch of the plant with roots attached.
- Replant the divided plant in the soil.
- Keep the transplant moist but not soggy while it becomes established.
How to Grow Brass Buttons from Seed
You can sow seeds indoors in a seed-starting mix roughly eight weeks before your area's last projected frost date in the spring. Keep the seed tray warm (about 70 degrees Fahrenheit) for best results. Germination takes place in 2 to 3 weeks.
The seeds are extremely small, found inside the tiny fruits left behind from the golden flowers. It can be troublesome to collect and plant these seeds, so root division is the much more common means of propagation.
Potting and Repotting Brass Buttons
Brass buttons plants grow well in just about any commercial potting mix, whether soil-free, sandy cactus mix, or rich loam. When potting up the plants, don't dig a hole, as the shallow roots don't need a large volume of soil cover. Lay the plants on the soil surface, and gently pat and scoop the soil around the plants to secure them in place.
Brass buttons plants add interest to terrariums and fairy gardens, where their ferny foliage and purplish hue contrast nicely with other petite plants such as baby's tears or kalanchoe. In the pampered environment of a container, plants will spread quickly, so divide them as needed to keep them in bounds.
Common Pests & Plant Diseases
This plant has almost zero problems with pests and diseases. Aphids can be a nuisance on newly emerging foliage in the spring. Blast them away with a strong jet of water. Plants stressed by dry conditions are susceptible to mites.
Common Problems With Brass Buttons
Brass buttons are easy to grow but can have minor problems. If you see any of the following, take steps to amend the issue.
Leaves Turning Brown
Brass buttons plants are not drought tolerant and those that dry out may exhibit browning of leaf edges or loss of foliage.
Brass buttons don't like growing in too much sun. Avoid very hot, sunny spots, as this plant can scorch and does need a somewhat humid environment.
Are brass buttons and tansy the same plant?
With their similar fern-like foliage and yellow disc flowers, the tansy plant (Tanacetum vulgare) looks like a close relative of the brass buttons plant. A perennial herb hardy in zones 3 to 11, tansy quickly distinguishes itself from brass buttons with its stature: Tansy plants grow to 4 feet, while brass buttons never exceed a few inches. If you add some tansy plants to your garden, deadhead the flowers after they bloom to keep the numerous volunteers from taking over your flowerbed.
Can I buy seeds for brass buttons plants?
Brass button plant seeds may be difficult to find. Your best bet is to buy a starter plant from a retailer or propagate using cuttings as detailed above.
What color do brass button plants turn in the fall and winter?
Brass buttons foliage turns a brassy bronze or purplish color in the fall. In cooler climates, the foliage should die back to the ground for the winter until it regenerates in the spring.
How is this plant best used in the landscape?
The deeply divided foliage and vibrant yellow spring flowers of brass buttons form a dense and sturdy mat underfoot. Brass buttons plants are ideal as path edging, a way to fill the void between stepping stones, or even as lawn alternatives that withstand foot traffic.
Cotula coronopifolia. California Invasive Plant Council.