There are safe and effective alternatives to using pesticides and chemical fertilizers on your lawn and garden. In fact, organic gardening methods protect the long-term health of the soil – the foundation for growing healthy plants that have higher natural resistance to weeds, pests, and disease.
Natural Pest Control Tips
Tips for Healthy Lawns
Alaska Community Action on Toxics offers workshops to share knowledge and tips for successful organic gardening in Southcentral Alaska. Our workshops are led by Alaskans with extensive experience growing food organically in our northern climate. More info can be found on our facebook page and www.yarducopia.org
You can prevent or minimize pest damage and weed problems by promoting overall soil health, providing plants with adequate nutrients from organic sources, watering deeply, increasing plant diversity, and detecting and responding to problems early.
- Healthy plants are naturally more resistant to weeds, pests and disease.Weaker, unhealthy plants are more prone to disease and more susceptible to being taken over by weeds or ravaged by pests than are healthy ones. This is true of turf grass, flowers, vegetables, trees, and shrubs.
- Promote plant health by maintaining healthy soil, providing adequate organic nutrients, and proper watering.
- Healthy soils support healthy plants.Healthy soils contain plenty of organic matter, have adequate nutrients, and are alive with beneficial soil food-web organisms such as bacteria, microorganisms, fungi, nematodes, and earthworms.
- Know your soil! Get a soil test. The Alaska Cooperative Extension Service can tell you how.
- Provide your plants with organic sources of nitrogen, phosphorous, and potassium in sufficient quantities to cultivate strong healthy plants. See organic fertilizers vs. chemical fertilizers
- Add compost or other organic matter to build and maintain soil health.
- Most insects are beneficial – not harmful—to plants.Beneficial insects include pollinators and those that feed on pest species.
- Grow herb and flower varieties in your garden that attract beneficial insects. Examples that do well in Alaska include: cosmos, catmint, coriander.
- Avoid the use of pesticides as they do not discern between the harmful insects and the beneficial ones – they poison all of them, as well as other animals, and people.
- Planting a diversity of vegetables, herbs, and flowers supports overall garden health. Growing a wide array of vegetables, herbs, and flowers together can help to prevent pest problems as well as increase productivity.
- Utilize companion planting techniques. Companion planting is the practice of placing two or more different types of plants next to one another to achieve a benefit. Some plants are known to enhance the flavor or growth rate of other varieties and many herbs and flowers have the natural ability to repel pest insects or attract beneficial insects.
- Grow herbs and flowers that suppress or repel pests. Some examples that thrive in Alaska include: chives, nasturtium, and marigolds.
- Plant a number of different varieties of your favorite crops. Some varieties may do better than others. Increasing diversity will help to protect against the loss of any one type of plant to pests, disease, or unfavorable conditions.
- Know your pests.Slugs eat virtually anything, whereas root maggots target cole crops (broccoli, cabbage, turnips for example.) Understanding the life cycle, diet, and preferred habitat of pests will go a long way in preventing problems.
- Rotate crops each year to prevent pests that have overwintered from the previous year from destroying this year’s crop.
- Plant a variety of vegetables, herbs, and flowers together to make it more difficult for pests to find their target species. Intercropping confuses pests.
- Remove pests by hand early in the season. Early detection and response can significantly minimize damage later.
- When problems do arise, utilize Natural Pest Control Methods.
All plants require adequate nitrogen (N), phosphorus (P), and potassium (K) for healthy growth. In addition to these three key nutrients, plants also need calcium, sulfur, magnesium and certain trace minerals to thrive.
Here are some of the key differences between organic fertilizers and chemical fertilizers:
- Organic fertilizers come from organic materials such as cottonseed meal, fish emulsion, manure, bone meal, kelp, etc. whereas chemical fertilizers are synthesized from inorganic materials.
- Organic nutrients can improve the long-term health of the soil whereas chemical fertilizers will gradually deplete and degrade the soil, eventually resulting in reduced productivity.
- Organic nutrients increase the abundance of microorganisms in the soil whereas chemical fertilizers will kill important living organisms in the soil. (For example, the sulfuric and hydrochloric acids found in many chemical fertilizers destroy certain bacteria that make nitrogen available to plants.)
- Organic sources of nutrients replenish trace minerals taken up by plants, whereas chemical fertilizers do not.
- Over-fertilizing plants with chemical fertilizers will harm them and can even kill them. With the exception of certain manures (chicken, for example), it is difficult to over-fertilize with organic fertilizers.
- Use of chemical fertilizers can lead to weakened plants that are more vulnerable to pests (leading gardeners to turn to pesticides) and prone to disease, whereas use of organic fertilizers builds healthy soils that support strong plants with better natural resistance to pests and disease.
- Organic fertilizers release their nutrients more slowly than chemical fertilizers.
Of all of the differences between organic and chemical fertilizers, the slow release of nutrients from organic sources is the one that gives gardeners trouble, but it doesn’t have to. In Alaska, if you add organic fertilizer in the fall, the nutrients will be available in the soil by the time the danger of frost has passed and you are ready to plant in the spring. You can also apply organic liquid fertilizers to give your plants a nutrient boost during the growing season.
Compost is decomposed organic matter. It is primarily used as a soil amendment to improve soil structure. The nutrient content of compost depends on what is in it. Even in Alaska’s relatively cool climate, it’s possible to make your own compost in just 6 – 8 weeks.
- Alaska Methods for successful composting– from Good Earth Garden School
- Publications by the UAF Cooperative Extension Service
Healthy soil requires abundance and diversity of beneficial food-web organisms. Compost tea is a highly effective and completely organic concentrated solution full of these living beneficial microorganisms.
Properly brewed compost tea will:
|Compost tea is made from high quality compost, a microbial food source, oxygen, and de-chlorinated water. We brew our own “Fertili-Tea” compost tea every week throughout the summer. Look for ACAT’s compost tea at Farmer’s Markets in Anchorage.|
|Compost Tea Information Sheet|
While they may provide a quick fix, synthetic chemical fertilizers and pesticides decrease soil health over time resulting in a vicious cycle requiring that more and more chemicals be used to achieve the same results.
Build your lawn’s natural resistance to weeds and pests by encouraging healthy soil through proper watering and mowing as well as lawn aeration.
- Get a soil test to find out what nutrients may be needed. Address any deficiencies using organic fertilizers. Apply ¼ inch of compost as a top dressing each spring. Apply compost tea a few times during the growing season.
- In spring, reseed bare patches or thin areas of your lawn. Healthy turf will out-compete weeds.
- Be sure to remove excess thatch which is a dense layer of dead root material that can build up between the roots and the grass. You can remove thatch with a thatch rake or rent a dethatcher.
- Aerate your lawn if needed. Aeration involves making holes in the lawn either by extracting plugs of soil or pushing a rod into the soil. Aeration helps oxygen, water, and nutrients reach turf roots.
- Water deeply, but less often. Deeper watering promotes healthier root growth.
- Mow high – increase mowing height to 2 ½ to 3 inches. Mowing high increases drought resistance and allows fro better photosynthesis. Mow frequently enough to remove no more than one third of the grass height in any mowing.
- Hand-pull weeds. Make it a family affair!
- A spot treatment with a 50% mix of household vinegar and hot water can be effective against dandelions, but be careful not to allow it to get on other plants.
- Apply natural pre-emergent herbicides such as corn gluten meal to weed-prone areas, especially to prevent dandelions.
- Use non-toxic alternatives to chemical sprays.
There is no doubt that certain pests can wreak havoc in an Alaskan garden. In addition to following the preventive tips outlined above, here are suggested non-chemical methods of dealing with pests common to Alaska.
- Tolerate low numbers of aphids. Most plants can handle a low to moderate number.
- Plant a variety of flowering plants to attract beneficial insects that feed on aphids.
- Use a high pressure spray of water frequently to dislodge aphids.
- Manually rub aphids off of plants with your fingers.
- Prune away heavily infested plant parts, but avoid excessive pruning.
- Avoid high nitrogen quick release fertilizers because aphids reproduce more quickly on plants with high levels of nitrogen in their leaves and buds.
- Ensure that your plants are receiving adequate water and light so they will be healthier and can resist aphids.
- Use floating row cover (a spun polyester fabric available at most garden supply stores), to exclude pests while allowing light and nutrients to reach the plants.
- Rotate crops and plant in ground that was free of root maggots and their host plant from the previous year.
- Do not compost plants that were infested by root maggots as these may introduce root maggots into your soil when you use the compost.
- Floating row covers and waterproof collars around the plant stem can reduce infestation. Be sure to bury the edges of the row cover in the soil.
- Ellen Vande Visse of Good Earth Gardening School recommends the use of “trap crops.” She suggests planting a circle of sacrificial radishes around your cole crops. The root maggots will feed on the radishes first, giving your other crops more time to grow.
- If possible, delay planting until soil warms to avoid planting during peak egg laying periods.
- Introduce or encourage predation by beneficial nematodes.
- Monitoring your garden in early spring can make a big impact. If you find a plant that has been severed at the stalk, scratch the soil near the plant to find the cutworms. You will find more cutworms if you monitor your garden at night as this is the time when they are most active.
- Keep areas surrounding garden free of weeds and sod to decrease cutworm habitat.
- Turn the soil in the spring and fall to expose them to weather and predators.
- Make collars to protect young transplants. You can use cardboard, stiff paper, aluminum foil, plastic or tin cans with both ends removed to fashion a collar. The collar should extend 1-2” into the soil and 2-3” above the soil.
- Putting a wooden stick next to your plant will prevent cutworms from completely encircling your plant and biting it off at the stalk.
- Floating row covers can be placed around developing plants to keep cutworms out, but this will not prevent damage from cutworms that overwintered in the soil. Reusable fabric row covers are recommended.
- Encourage the cutworms’ natural predators which include ground beetles, rove beetles, spiders, wasps, toads, parasitic nematodes and birds.
Birch leaf rollers:
- Maintain tree health and vigor by ensuring that the trees are properly irrigated.
- Prevent bark, limb and root injuries by keeping lawnmowers and weed whackers away from trees.
- Avoid damaging the root system by driving on roots, putting excessive weight on roots, or removing soil above the roots.
- Properly prune heavily infested twigs.
- Slugs like to hide in moist, shaded locations, underneath pots, boards, logs, cardboard boxes, weeds, and rocks. One of the first things you can try is eliminating these hiding places from your garden.
- Create your own hiding places to trap slugs. Turn a flower pot upside down or use pebbles to prop up a pot or board off the ground by 1 inch. You can place beer or wilted weeds under the traps to attract slugs. Check the trap once a day and dispose of slugs that you find.
- Place a ring of coffee grounds, finely ground egg shells or wood ash a few inches away from your seedlings to repel slugs.
- Hunt for slugs on cloudy days or at night and use kitchen tongs to remove them from plants.
The following websites provide more information about non-toxic methods of pest control: