Weeds & Pests
Can they really be managed?
The struggle is real on finding organic solutions to manage weeds and pests on 3 acres of land. Since the beginning of my gardening journey, I’ve hand pulled weeds and sprayed soapy water on most pests. It was manageable on my small lot in the burbs, but then became an increasing source of pain at the community garden where pathways of crusher fines began to get weeds growing on top, and now the thought of pests damaging an entire expensive dahlia crop is a real threat that keeps me up at night. It is a completely different ballgame now and I sympathize with farmers who grow on 25 acres or hundreds of acres.
I learned from my CSU Master Gardener Training that there is a difference between weed “control” and weed “management.” Every gardener needs to wrap their mind around this because it can save you feelings of guilt. Here’s the secret—you never really control anything in life…including weeds! They are part of nature and will find ways into your garden by way of wind, birds, tilling, etc but you can manage them. (Just like that…insert sigh of relief and another life lesson from the garden). Shifting how you approach weeds is important. So what does managing weeds and pests organically look like? First, it requires you to be proactive and begin the management process in March and April, before weeds germinate or bugs hatch and grow into adults. And secondly, it requires you to develop a consistent management strategy every year. Technically, this is referred to as an Integrated Weed or Pest Management Program.
If you came to our property this summer, you saw a lot of weeds. When we bought our property, weeds were growing up the fence line, in the rocks, grass, and field, and once I plowed the soil I brought up thousands of weed seeds that have been laying dormant for hundreds of years. Thats how weed seeds work. They can live deep in the soil for years but as soon as you start working the soil you bring them to the surface where they find the right conditions to germinate. They also fly in from neighboring lots or open spaces where weeds go to seed. This is how weeds grow on top of the areas you rocked or mulched. This summer I resorted to telling visitors if they saw weeds they knew it was safe to come in—but deep down, lets be honest, I despise weeds!
This year we are putting a weed and pest management plan in place that is equally important to the plan we have for our flower fields. Here are some important elements that you may also want to consider for your own property:
Weed Management
In building our hardscape areas and treating current pathways, we are doing the following:
Weed Fabric & Rocks or Crusher Fines on all pathways in our backyard area (not fields)
Pre-Emergent every spring of Corn Gluten— This is a natural pre-emergent that works by drying out the weed as soon as it cracks open. If you put it down after the roots have developed it will not work. This is available in a liquid or granular form and is OMNI rated. It must be spread early in the season, and at the correct rate so follow the instructions well. Read about The Magic of Corn Gluten here. It can be purchased online at Arbico Organic. We are planning to use this on our lawn and mulched areas of landscape and field as well.
In building our landscape areas with perennials of lavender, roses, woodies, shrubs and trees, we are doing this:
Compost & Fertilizer on beds
Planting healthy plants only (if they look sad at the beginning toss them out)
Cardboard around all plants (instead of fabric)
Drip Irrigation lines (the expensive kind that has emitters)
Mulch - 2-3” of untreated mulch
For our flower fields, we use a different approach:
Fabric on Annual Crops - We buy Dewitt Sunbelt 6’x300’ rolls of landscape fabric 3.2 oz, which we burn planting holes into. Then we pull it back in the fall and store for the next season. We buy our fabric locally from ACW Supply in Denver. (Ask for Jake!)
Cover Crops - Winter Rye Grass has grown well for us as a seasonally cover crop to build organic matter in a new fields and to suppress some weeds. We’ve planted in August and November and both have germinated well. I haven’t found a local source yet so we are buying 50 lb bags from Johnny’s. If there is a local nursery, I’d love to know about it.
Silage Tarp - We plan to invest in silage tarps to cover rows that are dormant for the season. See this video from Johnny’s on how to use a Silage Tarp.
Hand Pulling - We will still have to hand pull weeds weekly, and will hire skilled labor 1x month if needed. Our favorite hand tools are the 5” stirrup hoe and a hori hori to scrape or pull weeds around fabric areas. Johnny’s or A.M Leonard are great places to find these.
Spot Spraying Natural Pesticides - Instead of spraying toxic chemicals we are trying non-selective pesticides commonly made from citrus oil or agriculture vinegar. I haven’t had much luck with agricultural vinegar so this season we are testing Avenger which is citrus based. This must be sprayed when there is no wind, and it’s a hot sunny day because it burns the weeds.
For destroying weeds after they are pulled, we are going to explore this approach:
Peppering or “Ashing” - Instead of trying to compost weeds, or send them to the landfill, we are going to explore a biodynamic method of burning weeds and pests as a means for eradicating them from an area. See this article from the Biodynamic Association for an educational bulletin.
Pest Management
The pests that are top of mind for our farm are Cucumber Beetles, Grasshoppers, and Japanese Beetles. The beetles love roses and dahlias and the grasshoppers love lavender. While I have not seen many Japanese Beetles in Arvada, I know they are in Denver so I want to be proactive, and the grasshoppers are the one pest that go after lavender. Last year I tried a biological control and I saw a dramatic decrease in grasshoppers after I used it in the spring so I plan to use it again, as well as a few other biocontrols. Just as in managing weeds, you must develop an Integrated Pest Management Program. Here is what we are doing to manage pest on our property:
Compost Tea & Biodynamic Preps - Keeping plants healthy with weekly spraying of compost tea and seasonal spraying of Biodynamic Preparations (500, 501, 508) go a long way in strengthen plants own abilities to fight off pests. We use biodynamic compost and worm castings purchased from Paonia Soil to make our tea, and buy Biodynamic Preparations online from Josephine Porter Institute. Here is a quick explanation of the Biodynamic Preps. I mix them in our compost tea brewer and spray them with a battery operated sprayer.
Biodynamic Prep #500 Horn Manure is sprayed on soil or cover crops before they are tilled in at the beginning of the season (April/May).
Biodynamic Prep #501 Horn Silica is sprayed on foliage and helps the plants mature (June/July). I’ve seen visible changes in the strength of plants within a week after I spray this.
Biodynamic Prep #508 is sprayed as needed to control fungal disease like powdering mildew (August/September).
Cleaning Tools - I confess I haven’t been diligent at this but making sure tools are clean is important so you don’t spread disease from one plant to the next weakening their abilities to fight off pest or disease. At the beginning of the season, we’ll wash all snips and field hand tools in soapy water, or bleach water, and will continue to wash throughout the season.
Irrigate Properly - We grow in clay soils so learning to irrigate properly has been a learning curve. Clay soils retain water and does not allow water to spread out to surrounding areas as quickly as sandy soils so we’ve learned that placing drip lines closer together works better. When plants are young we water more frequently and as they mature we water more deeply (longer) and less frequent. Ensuring all drip lines work properly and replacing when needed is important so water isn’t pooling which weakens plants and gives pests a place to party.
Biological controls - These are living solutions found in nature. Think of them simply as an expansion of what you learned in Kindergarten by releasing Ladybugs. These solutions are alive so purchase them right when you plan to use them.
NemaSeek Beneficial Nematodes - Nematodes put down once the soil temperature reaches 40 degrees. Nematodes are beneficial microscopic organisms that kill insect pests that have a pupal larva stage (i.e. beetles). I’ve seen this applied by simply putting the powdering substance in the end of a cardboard tube that has duct tape on the bottom. Make a few holes in the duct tape to allow the powder to come out then walk your land and tap the tube on the ground spreading the substance as you walk.
NemAttack Beneficial Nematodes - This one goes after thrips which are common with dahlias.
Nolo Bail - This biocontrol infects grasshoppers, locusts, and crickets and we used it last year with noticeable results on our lavender.
Beneficial Insects - Assassin Bugs for our hot dry climate and the gardeners best friend—the Praying Mantis. Both of these predators came naturally to our fields last year but they can also be purchased through Arbico or your local nursery.
Chickens - We plan to increase our flock this spring and will be letting them roam free more often to eat bugs in our field.
Natural Pesticides - These are made from natural materials and are sprinkled around the perimeter of growing areas to kill specific insects. The two that we’ve used with success for earwigs are Bonide Bug Killer and Diatomaceious Earth.
Ultimately, the goal is to care for the land without having to use harmful chemicals. When I started my blog, I did so with the intention to courageously share my struggles just as much as I humbly share my successes. I hope by reading this article you feel relieved that you are not alone with battling weeds and pests. They are both part of the underbelly of gardening and will always be present. Its more about finding the right grip—not too tight and not too loose, just consistent. Sounds similar to a parenting talk I once heard that stuck with me… “parents need to be the loving brick walls for their children.” I guess no matter what you are growing, consistent boundaries always prevail.
Thanks for reading,
Gina