War on Weeds 鈥� Weeds are Everybody鈥檚 Problem
Pineappleweed
Pineappleweed (Chamomilla suaveolens) is a common summer annual broadleaf plant. Found commonly in gardens, lawns, cropland and open spaces, pineappleweed thrives in harsh soil conditions such as compacted soils and high traffic areas, but not in shade. Pineappleweed germinates in early spring and continues to germinate throughout the year. Flowers can be present all year beginning in late spring.
With lacey leaves and a pineapple smell, pineappleweed is easily identified. Cotyledons are bright green, narrow, thick, and fleshy, pointed or rounded at the tip, hairless, and are about 1/12 to 1/2 of an inch long and 1/25 of an inch wide. The leaves of the first pair are opposite to one another on the stem, hairless, and their leaf edges range from smooth to deeply lobed. Subsequent leaves are alternate to one another along the stem, deeply lobed to deeply divided into narrow fingerlike lobes, and form a stem. Seedlings grow as a rosette, then the plant branches upward into a small bush (6-12 inches high). Flower heads are found at the ends of stems, are egg shaped, and are composed of densely packed, tiny, non-showy, yellowish green flowers.
Integrated Pest Management (IPM) options
- Prevention — Learn to identify this plant. Never transport unknown plant material. Effective prevention includes maintaining healthy, competitive desirable vegetation.
- Mechanical — Hand-pull plants in planting beds prior to seed development.
- Chemical — Pre-emergent herbicides may not be effective since pineappleweed germinates year-round. 魅影直播 an appropriate post-emergent herbicide directly to target weeds. Many restricted and non-restricted use herbicides are 魅影直播, for more information visit then search “pineappleweed” in the weed section. Always read and follow herbicide label directions.
Idaho is a wonderful place with awesome natural resources, landscapes, agriculture and recreational opportunities. Weeds threaten all the things that we love about Idaho. To detect, contain and control weeds in Idaho we have declared “War on Weeds.” These short articles are designed to give a brief description of each species, an explanation about why it’s a problem, insights into identification and Integrated Pest Management control options. — Justin Hatch
View or Download (pdf)
- Pineappleweed, 8-15
2024-2025 (pdf)
- Bur buttercup, 1-22
- Buckhorn plantain, 1-29
- Kochia, 2-5
- Feathered mosquito fern, 2-12
- Flowering rush, 2-17
- Jointed goatgrass, 2-24
- Giant hogweed, 3-2
- Hoary alyssum, 3-9
- Hydrilla, 3-16
- Giant knotweed, 3-23
- Johnsongrass, 3-30
- Quackgrass toms, 4-6
- Meadow hawkweed, 4-13
- Meadow knapweed, 4-20
- Mediterranean sage, 4-29
- Milium, 5-6
- Orange hawkweed, 5-11
- Parrotfeather milfoil, 5-24
- Perennial pepperweed, 6-1
- Dryer's woad, 6-8
- Purple starthistle, 6-29
- Saltcedar, 7-6
- Black Henbane, 7-24
- Scotch Broom, 8-3
- Squarrose knapweed, 8-10
- Syrian beancaper, 8-17
- Tall hawkweed, 10-5
- Water chestnut, 10-12
- Russian thistle, 10-19
- Musk thistle, 10-26
- Water hyacinth, 11-2
- Yellow devil hawkweed, 11-9
- Yellow flag iris, 11-16
- Eurasian watermilfoil, 11-23
- Yellow floating heart, 11-30
- Yellow starthistle, 12-7
- Phragmites, 12-14
- Common frogbit, 12-28
- Bittersweet nightshade, 1-4-25
- Diffuse knapweed, 1-11
- Russian knapweed, 2-12
- Spotted knapweed, 2-22
- Scotch thistle, 3-8
- White bryony, 3-15
- Canada thistle, 3-22
- Western salsify, 3-29
- Leafy spurge, 4-5
- Common burdock, 4-12
- Siberian elm, 4-19
- Field bindweed, 4-26
- Annual bluegrass, 5-17
- Large crabgrass, 5-24
- Congongrass, 5-31
- Turkish thistle, 6-7
- Buffalobur, 7-19
- Small bugloss, 7-26
- Puncturevine, 8-9
- Pineappleweed, 8-15
Photo courtesy of Caleb Slemmons, National Ecological Observatory Network, Bugwood.org.