Organic Weed Control
Win the war against your weeds!
Organic weed control calls for timely applications of corn gluten to prevent germination, plus spot treatments to address perennial weeds and annuals which have already sprouted. To clear a wide area in preparation for a new bed, try sheet mulching.
NO method of weed control is permanent or perfect. Weeds can blow in with the wind, or be deposited by birds or animals. Some weed seeds can lie dormant for up to 20 years or more before germinating, and some weeds can root underground and travel great distances. Remember: Weeds are often an indication of a poor, disturbed, or bare soil. Following good organic maintenance practices will create a healthy turf and landscape.
- Avoid compaction, or unnecessary tilling and digging of the soil.
- In addition, never leave any soil bare, rather cover bare soil with at least two or three inches of mulch to prevent weeds and protect soil from erosion, heat, and drought.
Natural Weed Prevention
Corn gluten is a natural pre-emergent herbicide to help control annual lawn and garden weeds. Corn gluten prevents a majority of annual weed seeds from sprouting. The dry corn gluten is also a fertilizer containing 9% nitrogen.
Timing is the most important factor in the effectiveness of corn gluten. Corn gluten must be present on the soil before weed seeds sprout (germinate) in order to be effective. Apply corn gluten in late winter and late summer/early fall:
- Mid-January – This application of corn gluten helps control spring and summer weeds, such as crabgrass and sandbur. As the soil begins to warm in late winter is the correct time to apply corn gluten. Especially with sandburs, multiple applications may be necessary. Corn gluten may be applied every 6 weeks through September.
- Mid-September – This application helps control fall and winter weeds, such as annual bluegrass, rescuegrass, henbit, chickweed, bur clover, mustards, and annual thistles. This is the proper time to fertilize lawns, so corn gluten will suffice as the fall fertilizer, too. The best time to apply is when we feel the first break in the hot weather of summer – at the first hint of cooler weather.
Weed seeds can germinate at any time of year. In cases of severe weed infestation apply corn gluten every 6 weeks during the growing season.
The recommended application rate is 20 pounds per 1000 square feet or 2 pounds per 100 square feet. Do not apply compost, compost tea, or soil activator for 6 – 8 weeks after applying corn gluten, as it may interfere with the effectiveness of the corn gluten. In garden beds, hand pull existing weeds, and then apply corn gluten. Reapply whenever the soil is turned. On a lawn, a drop spreader is ideal for spreading corn gluten. After application, water the area and then allow it to dry for several days. Corn gluten is most effective under these conditions, so avoid applying prior to a rainy period. Do not distribute seeds into the area. Corn gluten will prevent their germination for the next 6-8 weeks!
Off with their heads!
Certain products are designed to desiccate the top growth of weeds, and are most effective on annual weeds, though repeated applications can work on perennial plants. These liquids are best applied on a sunny day, and function by removing the protective coating from the surface of the leaf, causing it to dry out. The principle behind it is simple: a plant without leaves cannot make food, and no plant can survive without food. Apply with care, as they are non-selective and will work equally well on weeds or tomatoes. Once dry, they are safe for kids or pets, and do not leave any soil residue.
Out by the roots!
While perhaps not the easiest or fastest solution, pulling the weeds out by the roots is both highly effective and organic! To eliminate bending and reaching, look for specialized tools, such as the foot-operated Grandpa’s Weeder.
Browse our extensive tool selection & find great gadgets to make your life easier as you tidy your garden.
Weeds in Lawn Grass
Control of broad leaved weeds in lawn grass is possible using products, such as Pulverize, that contain the organically acceptable ingredient Iron HEDTA. This type of product works because broadleaf weeds absorb and use iron differently to lawn grasses. Broadleaf plants take it up in far greater quantities than the grass, which leads to tissue death, so the weeds turn brown or black and die, while the grass is unaffected. It works well on younger weeds but well established mature weeds are better controlled by manual pulling. Multiple applications may be needed to control persistent weeds. As with all liquid products, do not use when the daytime temperature is above 85°F.
Start over frome scratch
Sheet mulching can be used where a gardener wants to start from scratch. It is an efficient method of eliminating weeds. Sheet mulching is most effective when done during the active growing season, but can still be practical during the winter, though it may take longer. Here are the steps:
- Mow or use a string trimmer to cut the grass and/or weeds down to the ground. Leave the clippings.
- Spread ½” – 1” of good compost over freshly trimmed area. Water in this layer.
- Layer over the compost with several layers of paper materials. Leave at least 4 inches of overlap between pieces, and make sure there are no gaps. Water this layer until thoroughly wet. You can mix and match the following:
- Newspapers (about a quarter inch thickness, about 10 – 15 sheets)
- Plain brown corrugated cardboard (remove plastic tape and metal staples)
- Brown paper (such as paint masking paper)
- At this point you have two options:
- If you are creating a raised bed, build your border, then fill the bed with a prepared soil, and proceed to plant!
- If you’re not ready to plant yet, cover the cardboard layer with two or more inches of any mulch. Leave the layers undisturbed for at least two or three months. Water the area regularly – once every week or two if you can.
- If you are creating a raised bed, build your border, then fill the bed with a prepared soil, and proceed to plant!
These layers can be built around plants in an existing bed too, but keep them at least 2” – 3” away from the stem of the plant to prevent rotting. Weeds will still need to be diligently pulled from the area around the stem.