WEEDS!

1. WEEDS! Paul Benda Argonne Garden Club May 2013

2. Or rather… The cons outweigh the uses.

3. Why are some plants weeds? • Most noxious weeds are of Eurasian origin. • Introduced for forage, erosion control, wildlife (Crownvetch). Culinary uses (Garlic mustard). • Accidental contamination of cereal grain supplies (Canada Thistle, Velvetleaf). • Many not considered “weeds” back home (Purslane). • Grow early/late compared to natives/crops. • Able to grow well where other plants cannot. • No major pests, diseases. • No major economic uses, just damage.

4. Some Useful Weeds Creeping Charlie, Gill-over-the-ground – Glechomahederacea, perennial, mint family. • Beer clarifier & preservative, predates hops. • Herbal tea. • Cooked & fresh leaf. • Leaves high in Vitamin C. • Groundcover. • Brittle stems root easily.

5. Some Useful Weeds • Dandelion – Taraxacumofficinale, perennial, lettuce family. • Single plant can make over 5000 seeds/year. • Leaves usually cooked, high in vitamins, minerals. • Wine from flowers. • Root tea is digestive tonic and diuretic. • Roots resist shallow weeding.

6. Some Useful Weeds • Lambs Quarters – Chenopodium album, annual, beet family. • Important food plant in ancient Europe & modern India. • Nutritious leaves raw or cooked, similar to spinach. • Seeds nutritious, similar to Quinoa.

7. Some Useful Weeds • Purslane– Portulacaoleracea, annual, purslane (moss rose) family. • Widely eaten in Europe & Mexico - nutritious leaves raw or cooked, high in vitamins, Omega-3 fatty acids. • Very drought tolerant, can switch to CAM. • Traps CO2 at night, • Converts to malic acid then glucose in day. • Morning picked leaves the most sour.

8. Weed Propagation: Roots & Stems • Mainly perennials. • Very hard to control due to extensive underground reserves. • Root: Crownvetch, Canada thistle, bindweed. • Roots may go over 10 feet down. • Stem: creeping charlie, quackgrass. • Weave into turf, among cultivated plants.

9. Weed Propagation: Seeds • Mainly annuals/biennials. • Fast growing early in season (cool season). • Produce thousands of seeds, usually wind dispersed. • Seeds may last to 15-40 years (up to 100 years) in soil. • Plenty of seedy perennial weeds (Thistles). “One years seeding makes seven years weeding.”

10. The Nastiest Weeds of Argonne Subject to debate by area & gardener. • Crownvetch • Canada thistle • Spotted spurge & purslane • Prickly lettuce & dandelion • Bindweed • Creeping Charlie • Quackgrass , orchardgrass& crabgrass. • Add yours here…

11. The Nastiest at Argonne: Crownvetch • Coronillavaria, perennial, bean family. • Imported from Europe for erosion control. • Extensively planted by US & state government on mine spoils, highway embankments. • Roots grow over 10 feet. • Seeds last 15 years in soil.

12. The Nastiest at Argonne: Canada Thistle • Cirsiumarvense, perennial, lettuce family. • Vast root system stores nutrients. • Repeated pulling/mowing to deplete reserves. • Prolific seed producer: wind dispersal.

13. The Nastiest at Argonne: Spotted or Prostrate Spurge • Euphorbia maculata, annual, spurge family. • Native to N America. • Stems fragile, milky sap irritating to skin. • Strong fibrous roots, hard to pull.

14. The Nastiest at Argonne: Prickly Lettuce • Latucaserriola, annual/biennial. • Extensive brittle tap root. • High seed production: wind. • Gets very spiny with age. • Bitter milky sap is soporific and analgesic.

15. The Nastiest at Argonne: Bindweed • Convolvulus arvensis, perennial, Morning Glory family. • Extensive brittle root system. • Major agricultural weed. • Choking vine produces seed.

16. The Nastiest at Argonne: Grasses • Quackgrass: creeping perennial, extensive brittle root system. • Orchardgrass: bunching perennial, very tough. • Crabgrass: warm annual, brittle stems.

17. Weed Control: Methods • Cultivation, weeding, pulling • Trenching, edging • Mulch, covering • Mowing • Chemicals • Fire

18. Weeding Tools • Cultivation: hoe, cultivators. • Digging: weeders, trowels, spades, pitchforks. • Trenching, edging: flat spades, edgers.

19. Hand Pulling is…Labor Intensive …but very effective.

20. Weed Control: Edging and Trenching • Edging: clean look, best for turfgrasses. • Trenching: best for crownvetch, bindweed, quackgrass, orchardgrass.

21. Weed Control:Mulching

22. Don’t give up!