There are a number of varieties of weeds that you would do well to be aware of. Weed control is one of the main tasks you need to carry out often to maintain your garden. A garden free of weeds is healthier, more attractive, and indicates better management than one that has been invaded and worse still, overgrown with weeds.
Different regions report different weeds as being the most difficult to manage. Even different garden types and golf courses differ in their list of most annoying weeds. Nonetheless there is more or less a common consensus on the typical offending weed types, at least based on my research. Some of the most commonly reported weeds are Bermuda grass, crabgrass, marestail, dandelion, johnsongrass, giant ragweed, and yellow oxalis.
Organic herbicides are gaining popularity as safer alternatives to the conventional, chemical weed killers. There are a number of organic herbicides like Burnout, Scythe, Nature’s Avenger, plain household vinegar, and WeedPharm with varying degrees of success. The drawback of organic herbicides is that they (generally) don’t work as quickly as a conventional herbicide; let’s say glyphosate (Roundup). But, that is a choice for everyone to make.
Bermuda grass (Cynodon dactylon) is the scourge of lawns and flower beds, but depending on how you view it, it can be a weed, or cultivated as a turf grass. It goes by many names, and the odd thing is that in Bermuda it is NOT a native species. It is prevalent in much of the world, although native to Asia and warm areas of the Old World.
Bermuda grass spreads by means of rhizomes, seeds and runners, and it is a creeping type of grass with an extensive root system that can reach 1 meter deep into the soil, although most of the roots stay within 50 cm of the surface.
The rhizomes and runners can invade shrub and flower beds, and once established, are difficult to control due to its deep roots. Removing them calls for removing the entire underground stem, so make sure to dig them up properly using a shovel and fork. Troublesome clumps can be eradicated gradually with the range of organic herbicides and methods available.
Blackberry (Rosaceae) is a perennial native of Europe, but thrives in all similar climates around the world. There are several hundred species of blackberry, and it is considered an invasive weed in Australia, New Zealand, and some American states like Oregon and Washington (“Himalaya” variety). Ironically, the fruits of blackberry are rich in antioxidants and therefore it is cultivated in Oregon for its fruit harvest, proving that a weed is only a weed as long it is regarded as such.
Most blackberry varieties are scrambling bushes growing to about 1-2 m high, and have stems that reach 7 m in length. It spreads rapidly by means of underground runners and seed dispersal (birds eat and spread its seeds).
In spring, pull out the young plants before they establish feeder roots, and cut back established plants and dig up the roots during the summer. Organic herbicides with acid solutions above 20% concentration appear to be effective in controlling blackberry; as does Greenergy’s Blackberry and Brush Block. Spray on new shoots when they are 6-12 inches tall.
Dandelion (Taraxacum) is a widespread, hardy, lawn weed that comprises about 60 species. Common dandelion (Taraxacum officinale) can thrive almost anywhere in the world’s mild climate regions. Dandelion spreads by wind-borne seed dispersal and sprouting root crowns. After pollination and flowering, dandelion releases its seeds from parachutes within the dead flower heads.
Flowering occurs all year round until the arrival of cold weather and the seeds can easily germinate all year round even after long periods of dormancy; while it can easily thrive in poor soils, making dandelion a superb colonizer – and notorious lawn weed.
The problem with dandelion is its fleshy taproots that grow deep and break off when being pulled. The best way to control them is to mow your lawn frequently. This stops the flowers from maturing into seed pods. Don’t mow too much though, as this weakens your existing lawn grass and encourages dandelions to invade. Also, leave some cover of grass clippings behind to reduce sunlight availability.
There are specialized tools for digging up dandelions, although it is not an easy task (especially if you have a large infestation).
Using organic herbicides is a better way of dealing with dandelions if pulling them out is not your cup of tea. Apply herbicides in spring or fall, when the dandelions are busy transferring nutrients from their leaves down to their roots. This raises the chances of killing the entire plant.