Like most community gardens, PAHL’s HBCG has big problems controlling nutsedge and Bermuda grass. These two weeds thrive in the moist, tilled soils of the garden. And while cardboard and mulch is a great way to provide beautiful walkways in the garden, this management style nurtures Bermuda grass (and fire ants). Nutsedge thrives in any moist environment Once these take hold in an organic garden, it can be extremely difficult to control without herbicides. Maintenance is not too bad though, once these weeds are under control. Use the tips here to get your garden and walkways weed-free and fabulous.
Nutsedge: Nutsedge is the easier of the two to control if you are vigilant about pulling it out. The best way to control nutsedge is to not let it get established in the first place. It is often introduced to the garden through contaminated topsoil or other soil amendments or materials.
Once you see patches of nutsedge growing in your garden, the sooner you take action, the better. Nutsedge survival is dependent on the underground tubers that store energy for the plant (shown below). Pull those tubers up!
For effective control: Remove small nutsedge plants before they have 5 to 6 leaves. This limits tuber production and in summer this is about every 2 to 3 weeks. Removing as much of the plant as possible will force the tuber to produce a new plant, drawing its energy reserves to produce new leaves. Repeated pulling of the nutsedge is important because the tubers become weakened over time. Once the tubers are weakened, other mechanical methods of control such as cardboard and mulch become much more effective.
Bermuda Grass: Karen Contreras (San Diego) effectively removes Bermuda grass by simply digging it out. Well, digging it out is not so simple. She digs down 4 to 6 inches when the soil is moist and turns over the soil to remove the plant and entire root.
The entire plant above and below ground needs to be removed because Bermuda grass spreads through underground rhizomes. Digging out Bermuda grass is time consuming and labor intensive but very effective. If you are removing it from a raised bed, be sure to remove as much as possible from seams in the bed, where the grass can hide.