Bentley Seed Co. Blog

In our last post, Natural Bug Repellents, we discussed the benefits and How To’s of making your own “natural” sprays to stop insect pests from attacking your garden plants—using other plants you’ve grown from seed. In this installment (third in the series), we discuss homegrown solutions for discouraging insect pests from entering your yard, in the first place, as well as keeping them off your skin. Some people swear by essential oils, made from plants like peppermint, for example, a topic we touched on in the last post, but there are some other plant-based repellents you can grow and use to good effect as well. Basil Basil is not only delicious in just about any dish imaginable, it’s a particularly wonderful herb to plant because house flies and mosquitoes hate it. If you live where your growing season includes hot, dry and sunny conditions, basil is easy to plant all around your yard where it will repel those insect pests that are not only a nuisance but are capable of transmitting disease as well. If possible, plant it adjacent to outdoor seating areas and doorways into the house. You can also make an insect repellent spray using fresh basil leaves, as follows: Pick six ounces of fresh basil leaves, clean them thoroughly and place them in a container such as a pitcher or glass jar. Pour four ounces of boiling water over the leaves and let the mixture steep for several hours. Remove the leaves and squeeze their remaining juices into the liquid. Pour the liquid into a spray bottle. Add four ounces of vodka (yes, we said vodka—it functions as a carrier) to the liquid and shake the mixture gently; your homemade insect repellent is ready to be sprayed on skin and clothing. Take care to keep this “adult” DIY repellent out of the reach of children and don’t get the spray in your eyes, nose or mouth. Mint Mint can be used the same way as basil to repel pests. To keep ants and mice out of the house, plant it all around your foundation. Be aware that it spreads readily and can take over your garden if you don’t keep it in check. Catnip A member of the mint family, catnip is a vigorous perennial distinguished more by its attractive foliage than by its unassuming purple flowers—a favorite among pollinators, in spite of their modest appearance. Hardy and drought-tolerant, catnip readily reseeds and can be a bit of a nuisance in a formal flower border, but it can be very useful for a variety of other purposes, including pest control. Catnip contains nepetalactone, an essential oil that gives it its characteristic odor, which researchers have found is significantly more effective than DEET in repelling mosquitoes. (Attention, urban dwellers, it is also effective at repelling cockroaches.) To use it to keep mosquitoes off your skin, you can simply crush it in your hands and rub it on your skin. For longer lasting protection, applying a spray containing catnip’s essential oil is more effective (and, admittedly, a lot more work as we describe in our last post in this series). Marigolds Though hardy, easy to grow, and ubiquitously beautiful in summer annual borders, marigolds don’t always get the respect they deserve. One thing that should earn them respect is that mosquitoes and many destructive insect pests absolutely abhor their scent, so they keep their distance. Marigolds contain pyrethrum, a compound used in many commercial insect repellents with a similar repellent benefit as DEET without being toxic to humans. You can easily make your own pesticide spray as follows: Collect one packed cup of marigold stems, leaves and flowers Mix them in a blender with two cups of water Place the mixture in a glass jar, capped tightly, and let steep for 24-48 hours. Shake it gently a few times while it steeps Strain out the pulp using a rag or cheesecloth Add six cups of water plus ½ tsp. Of Castile Soap to the liquid mixture and put in spray bottle and spray on the non-edible parts of plants to keep pests away. There is a variety of other flowers and herbs you can grow to both repel insects in the garden simply through their very presence or by using them in combination with other ingredients to produce insect repellent sprays. Stay tuned for more in future posts.

In our first post in this series, we outlined various ways to get rid of garden insect pests without resorting to commercial chemical pesticides which can create more problems than they solve. Mother Nature, in her inimitable wisdom, has provided us with an ingenious system of checks and balances in the garden whereby pests are kept in check by their natural predators. However, this system goes awry when powerful chemical insecticides are introduced because they can end up indiscriminately killing the beneficial insects—priceless pollinators, for example—along with the pests. One alternative we touched on previously is to make your own (DIY) garden bug repellents using herb and vegetable plants you’ve grown from seed. While not a panacea for your garden woes, they can provide some measure of relief—both in the garden and elsewhere. Peppermint – Essential Oil Garden Spray Peppermint’s popularity as a garden plant is a testament to the fact that it’s easy to grow and cultivate. In fact, it spreads easily and can become invasive if you’re not careful. You can harvest it and extract its essential oil to repel destructive garden insects including aphids, squash bugs, whiteflies, and beetles to name a few. You can also use it around the house to keep out mosquitoes, flies, ants, and other uninvited creepy crawlies. For ease of application, after you have extracted the oil, you can make a spray, diluting the oil with equal amounts of distilled water and witch hazel in a glass spray bottle. To create essential oil of peppermint, you will need the following: Peppermint leaves (fresh and unblemished) Base oil (aka “carrier oil”) such as almond, wheatgerm or grapeseed. Muslin or cheesecloth (for filtering) Mallet, pestle or similar tool Glass jar with tight-fitting lid Then follow these steps to create the essential oil: Harvest plant leaves before flowering. For best results, harvest leaves just after daybreak while they still have dew on them. Wash with cool water and let them air dry. Gently tap the leaves to release their oils without bruising or shredding the leaves which will make separating them from the liquid more difficult. Place the leaves in the jar and pour in base oil to cover them. Shake to blend. Leave jar in a warm place, out of direct sunlight for 24 hours or so. Strain oil through the muslin or cheesecloth, removing all the peppermint and discard. Add a new, fresh batch of peppermint leaves to the existing oil and leave for another 24 hours. Strain out the peppermint, as before. Repeat this 1-2 more times to achieve the desired oil strength Make sure no plant material remains in the oil mixture or it will spoil prematurely. Tomato Leaf Spray Another useful garden pest repellent can be made out of the leaves of your tomato plants simply and easily as follows: Harvest two cups of fresh tomato leaves. Chop the leaves into one quart of water and let them steep them overnight. Similar to the peppermint oil above, strain out the plant material and use the remaining liquid as a spray. As a member of the “nightshade” family, tomato plants’ leaves contain toxic compounds called alkaloids which kills destructive aphids but won’t harm beneficial insects. These are just two of the many natural pest repellents you can create on your own. Stay tuned for future posts covering additional ideas.

Do you hate bugs? You’re not alone. Most of us recall feeling similarly before we started working the earth; our outlook changed after learning, firsthand, how beneficial insects can be to our gardening efforts. For example, lady bugs, ground beetles, lacewings, damsel bugs, and tachinid flies are a few examples of insects who provide benefit in the garden by preying on parasitic insect pests. Opposite of the “good” bugs, garden insect pests such as leafminers, spider mites, mealybugs, and slugs and snails can wreak havoc in the garden in a matter of days in their relentless quest for nourishment which they typically get by sucking the juices out of plant leaves. In a perfect, balanced world, the good garden bugs keep the bad garden bugs in check. The problem is, in their haste to eradicate pests at the first sign of a problem, many people turn to man-made chemical insecticides for a quick fix. Unfortunately, these insecticides only exacerbate the problem over the long run: the pesticides kill off the beneficial insects while the garden pests remain, quickly developing resistance to the chemicals. The pests’ numbers quickly multiply in the absence of predators and they become an infestation causing major damage to our plants. It makes much more sense to figure out ways to deal with garden pests using safe, non-toxic, “natural” methods which will be sustainable over the long run. Preventing Garden Pests from Taking Over That old saw, “An ounce of prevention is worth a pound of cure” is apt for dealing with garden insect pests. Starting with rich, well drained soil, enhanced, if necessary, with organic compost will help ensure strong, healthy plants with a greater ability to fend off predators than weak ones. Regular application of organic fertilizer and deep watering will also contribute to plant health. Companion planting, rotating “crops” and regular weeding will also help keep pests at bay. “Natural” Pesticides and Repellents Many people choose to procure or create their own “natural” pesticides and repellents without using harsh chemicals including the following: Oil sprays Soap sprays Garlic or chile pepper spray (repellents) All-in-one sprays Neem oil Other “home” remedies such as milky spore and diatomaceous earth. Unfortunately, many “natural” pesticides have limited effectiveness and can leave harmful residue on garden crops, and harm beneficial insects; they should be used sparingly. Beneficial Garden Insects Otherwise, you can resort to biological methods to reduce the threat of pests, by populating your garden with the aforementioned beneficial insects. You can either attract these good bugs by growing their favorite plants, or buy them from a commercial provider and release them into the garden. Following is a sampling of common garden insect pests and some effective ways to get rid of them. You may encounter different types of pests, depending on the region in which you live. We will address additional common garden pests in future posts as part of a series. As always, we recommend contacting your local county extension cooperative for additional information. Common Garden Insect Pests Mealy Bugs – Related to scale insects, these are small, soft-bodied wingless insects which appear as white cottony masses on plants in warmer climates. In large numbers they can weaken plants by leaving a sticky residue, called Honeydew, making them vulnerable to sooty mold fungus. Symptoms: They can cause leaves to turn yellow and fall off prematurely. Susceptible Plants: Citrus and ornamental plants such as begonia and coleus. How to Control: Keep your plants healthy through regular fertilization and watering. Blast them with a spray of water from the garden hose with a sprayer attachment Insecticidal soap Neem oil All-in-one “kitchen insect spray” Spider Mites – A common threat to both indoor and outdoor plants, this member of the arachnid family can cause substantial destruction in a short period of time by sucking the fluids out of plant leaves. This pest overwinters as eggs in the leaves and bark of host plants and molts and proliferates in hot, dry conditions. They are easily transported by the wind, quickly expanding their area of infestation unless you stop them. Symptoms: You can barely see these tiny pests and probably won’t notice visible damage until there’s a large infestation. At first, the leaves will show tiny spots and then may turn yellow, curl and fall off. If you look closely, you can see their tight webs formed under leaves and along stems. Susceptible Plants: Squash, melons, sugar peas and beans and various ornamentals. How to Control: Chemical pesticides are counterproductive because they actually encourage the spread of these pests by killing off beneficial insects that prey on them. Moreover, it has been found that these pests quickly develop resistance. Here are some better suggestions: Stressed plants are more susceptible to pest infestation: be sure your plants are well-fertilized and well-watered. Prune leaves, stems and other infested parts of plants (including whole plants, if necessary) and discard in trash – not compost pile. Blast the plants with water from the hose, using a sprayer attachment. You should do this regularly throughout the season to prevent them from laying eggs and establishing colonies. Use Insecticidal soap to spot treat heavy infestations Obtain and release beneficial insects in the garden to prey on the mites. Keep a close eye out for repeat infestations during warm weather Leafminers – Larvae, appearing as small raised spots, deposited by various flies, moths, beetles and sawflies on the undersides of plant leaves which, upon hatching, “create mines” between the upper and lower surfaces in the process of sucking the fluid out of the leaves. This activity mars the plant’s appearance and can restrict growth. Mature larvae overwinter in the soil under host plants and mature through various lifecycle stages as the weather warms up in the spring. Several generations are produced each year. Symptoms: Winding tunnel patterns appear on the leaves which rarely out-and-out destroys most plants, but leave some vegetable crops desiccated, robbing them of much of their appeal and nutritional value. Susceptible Plants: Unfortunately, leafminers attack many different types of plants, including fruits, vegetables, flowers, trees and shrubs. They are particularly destructive to susceptible leafy greens such as swiss chard and spinach. How to Control: This is a tough one since the leaf miners are protected by the plant leaves for most of their life. Prevention is your best bet through the use of floating row covers, secured to the ground so no adults can get at the plants to lay their eggs. Otherwise, you can do the following: As always, healthy vigorous plants are better equipped to keep pests at bay. Keep your plants well fertilized and well watered throughout the season. Keep a close eye on your plants: at the first sign of tunneling, use your fingers to squeeze the tunnels in order to crush the larvae. If you are vigilant and do this regularly, you may be able to keep the infestation under control. Pick off and discard heavily damaged/infested leaves. Cover soil under infested plants with plastic mulch to prevent larvae from reaching the ground and reproducing. Slugs and Snails – Gardeners who live in a moist climate or have a moist shady section of the garden are probably well familiar with these destructive creatures. They have voracious appetites, are not picky eaters and leave a trail of slime in their wake of nightly destruction. Symptoms: Leaves that are torn and have gaping holes. Slime trails. Susceptible Plants: Most everything in the garden. How to Control – Commercial pesticides while widely available, can be toxic to birds, other wildlife and family pets; non-toxic methods are preferable of which there are many. For example, beer traps and grapefruit traps work well, as does diatomaceous earth. Preventative measures such as watering early in the day leaving the garden relatively dry at night when they do their foraging will discourage them. When pests attack your plants it can be really distressing to see all your hard work go down the drain. But you can keep them in check with some preventative maintenance along with careful, consistent monitoring of your plants and early intervention with non-toxic remedies. Stay tuned for Part Two in the series.