I’ve been asked by a few gardeners about some of the common weeds we seem to have in our small city gardens, and what is the best way to eliminate them. Here is a list of the common offenders you might see. This list is not all inclusive.
Keep in mind that just pulling from the top of the plant or cutting the tops off the weeds will not kill most weeds. You have to dig into the ground and pull out the roots. This may take a few seasons to eradicate weeds completely. One of my horticulture mentors told me “If you hear it snap when weeding, then you did not get the whole weed.”
See the photos below to help you identify what might be in your garden.
Cinquefoil (Potentilla) – This is a perennial plant with five palmately compound leaflets. It has a small yellow flower with 5 petals. The plant has a long taproot, and it will spread via underground runners (called stolons).
How to treat it: You can remove it by removing the tap root and removing the plant before it flowers and goes to seed. If you select to smother it, you must first remove the entire plant and then cover it with organic material. This will take several seasons to completely eradicate it.
Tall Morning Glory/Small White Morning Glory (Impomoea) – These are vines whose seedlings will develop a taproot. The growth of these is rapid. It branches and twines onto anything it can get it’s hands on. If it flowers, one plant can create up to 10,000 seeds. Seeds have a long dormancy period and grow rapidly in disturbed soil.
How to treat it: It is important to remove the vine by hand method and as much of the root as possible. Smothering with organic material so the leaves do not photosynthesize is recommended.
Yellow Nutsedge (Cyperus rotundus) – this grass-like sedge is spreading rapidly in Maryland. The plant grows and creates small nut-like tubers. These nutlets can lay dormant for up to 3 years before spouting.
How to treat it: The best way is to dig up the plan while young before it has developed underground nutlets. Older plants will require a bit of sifting to remove the grass and any nutlets you may find.
Wiregrass, Devil’s Grass, Bermuda Grass (Cynodon dactylon) – This grass is in lots of our plots and walkways. The blades are grey-green in color The stems are slightly flattened. As the stems reach new ground, they will reroot from the stems and from underground stolons.
How to treat it: By consistently manually pulling, cutting, and digging up the rhizomes and stolons. You need to be consistently removing it to remove it.
Canada Thistle (Circium arvense): We all have this one! This plant emerges as a rosette in fall and spring. The plant continuously produces new shoots. There are spines or sharp hair along the older stems. You will find a deep, fibrous taproot and lateral roots sprouting from the plant. New younger plants will sprout from the lateral roots in a circular patch and form a dense cluster of plants. Any portion of a root fragment can sprout a new plant.
How to treat it: Mechanical removal by digging out the roots. Do not let it go to seed. In off seasons, plant cover crops in the off season to smother out the plant. Cover unused garden space with organic material if not being planted.
These are just a few of the more common weeds we are all dealing with. I hope this is helpful in giving you directions on how to identify and remove the weeds.
The key is being consistent and persistent in your weeding practice.
Happy Gardening!