lessons from weeds a close look at non-native opportunistic plants
TRANSCRIPT
Lessons from WeedsA close look at non-native opportunistic plants
“Why do people want to kill plants that want to grow and grow plants that want to die?”
Weeds?
Non-natives Hard working & opportunistic Indicators of soil or environmental conditions
pH, N – P – K, water, compaction
Pros and Cons?
Negative contributions
Positive contributions
Contributions of hard working plants
Reduce soil erosion Mitigate soil compaction Improve soil (N fixing, biodynamic accumulation) Food source and habitat for beneficial insects Potential source of food and medicine Indicator of soil conditions
Classification review
Broadleaf (dicots) Grasses (monocots)
“control” Cultural (change the environment) Physical (get down there and pull) Biological (invasivores?) Chemical (the last resort)
Being an “invasivore”
Positive identification Understanding of growing conditions Free access Ethical foraging (rule of 3)
Chickweed - Broadleaf
INDICATORS: - High N - If stunted, low P, moisture
LIKELY SITES: - Shady - Fertilized CONTRIBUTION: - Food - Medicine
B, P
Stellaria media
Sow Thistle - Asteraceae
INDICATORS: - High N - neutral pH
LIKELY SITES: - Disturbed - Fertilized CONTRIBUTION: - Food, forage
Sonchus asper
Dandelion - Asteraceae
INDICATORS: - Moisture - Acidic soil
LIKELY SITES: - Disturbed - Fertilized CONTRIBUTION: Food, Medicine, Insectiary
Taraxacum officinale
Poison Hemlock - Apiaceae
INDICATORS: - Herbicide application
LIKELY SITES: - Disturbed - Fertilized CONTRIBUTION: Insectiary, Poison
Conium maculatum
Groundsel - Asteraceae
INDICATORS: - High fertility
LIKELY SITES: - Cultivated CONTRIBUTION: Medicinal, wildlife food and habitat.
1 plant = 25,000+ seeds
Mechanical
Senecio vulgaris
Nutsedge, Tigernut - Cyperaeceae - Grass (monocot)
INDICATORS: - Wet soil, poor drainage - acid pH
LIKELY SITES: - Overwatered - Neglected CONTRIBUTION: Nutritional tuber, medicinal, oil, cosmetics
Deep fragile roots
Cyperus esculentus
Mallow, Cheeseweed - Malvaceae
INDICATORS: - Deep N - Disturbed soil
LIKELY SITES: - Disturbed - Neglected CONTRIBUTION: - Food - Medicine
P, B
Malva parviflora
Nettle, Annual nettle, Small nettle - Urticaceae
INDICATORS: - Deep NPK LIKELY SITES: - Disturbed CONTRIBUTION: Insectiary, Biodynamic accumulatorMedicine, Food
Urtica urens
Pellitory of the Wall - Urticaceae
INDICATORS: - Heavy metals?
LIKELY SITES: - Neglected - the Wall CONTRIBUTION: Medicinal
Parietaria officinalis
Purslane, Verdolaga -Portulacaceae
INDICATORS: Deep moisture and soil nutrients. LIKELY SITES: - Compacted, - Cultivated sites CONTRIBUTION: Food (linoleic acid), medicinal, companion plant
Portulaca oleracea
Getting a handle on BROOMScotch broom
(Cytisus scoparius)
French broom(Genista
monspessulana)
Spanish broom
(Spartium junceum)
Portuguese broom
(Cytisus striatus)
Stems: 5-sided; star-shaped cross sectionLeaves: compound, 3 leaflets, deciduous, sometimes single on new twigs
Stems: 8 to 10 ridges; round cross sectionLeaves: compound, 3 leaflets, evergreen, usually dense
Stems: smooth or finely ribbed; round cross sectionLeaves: simple, deciduous, sparse
Stems: 8 to 10 ridges; round cross sectionLeaves: compound, 3 leaflets, deciduous, sometimes single on new twigs
Flowers at leaf axils
Flowers at branch tips
Flowers at branch tips
Flowers at leaf axils
Cytisus Scoparius SCOTCH BROOM
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74147.html
French Broom - Fabaceae
INDICATORS: - Low N
LIKELY SITES: - Disturbed - Eroded CONTRIBUTION: - Forage, dye - Prevents erosion
Mechanical. Seeds viable for 30+ yrs
Genista monspessulana
Sourgrass, Bermuda buttercup - Broadleaf
INDICATORS: - High N - neutral pH
LIKELY SITES: - Disturbed - Available CONTRIBUTION: - Food - Prevents erosion
Oxalis pes caprae
