GARDEN PESTS AND PROBLEMS



There is no permanent solution for getting rid of garden pests. It is an ongoing task, requiring constant diligence and patience.

SLUGS AND SNAILS


The following material was taken from Rodale's Landscape Problem Solver by Jeff and Liz Ball.

BEST CONTROL STRATEGY

Set up a barrier to keep slugs off vulnerable plants or out of your garden. Handpicking will work if you begin early in the season.

SLUG TRAPS

The following are some examples of slug traps:

  • containers
  • trap crops
  • other devices.

    Use small covered containers filled with beer or slug poison. I will go into more detail on this later.

    Slugs are especially fond of hostas. This would be an example of a trap crop. Plant a few that you won't mind sacrificing to lure slugs away from other ornamental plantings. Collect and destroy slugs every evening.

    Snails will crawl under upturned clay flower pots, flat stones, or boards. Check underneath such items regularly. Place the pots on the shady side of your plants and elevate one edge to make it easy for snails to crawl inside. Check them twice a day; remove and destroy the pests.

    CONTROLLING SLUGS AND SNAILS

    The use of natural sprays, such as bug juice (so named because it is made from the pests themselves), are one way to control these garden pests. This is really good if you are feeling especially angry toward these pests. Here is the recipe: Crush some of the slugs, mix them with water, and spray the strained liquid on infested plants. This concoction is reputed to kill or repel slugs.

    As I mentioned earlier small containers filled with beer can be used to control slugs. Here is how to do it. Take a shallow dish, such as a pie plate, fill it with beer, and place it in the garden. Sink the pan into the soil to provide easy access. Slugs are attracted by the yeast; they will dive right in and drown. Replace the beer every few days or after a rain. So the next time you pop open a beer after a long hard day in the garden pour a little in your garden and do yourself a favor. Another method is to use 1 teaspoon of baker's yeast in 3 ounces of water. This is for those of you who don't like beer.

    A cover trap is anything that produces a cool, shady environment. Lay pieces of boards, old carpets, stones, or cabbage leaves in the garden, out of view. Check twice daily and remove and destroy any pests you find.

    Another method is to place hollowed out halves of gapefruit, open side down, in your garden. Check them several times a day and remove any slugs you find. This is effective for 2 to 3 days. Then you will have to replace them with fresh ones again. You can also try cantaloupe shells.

    Finally, if you don't mind grabbing their fat, slimy bodies, handpicking makes a sizable dent in slug populations right away. Just go out at night, with a flashlight and a container half filled with either kerosene or soapy water. Check the plants, boards, mulched areas, and walkways. You can use tweezers, wooden chopsticks, or forceps if you don't want to touch them. Or you can sprinkle table salt on them if you want to kill them without picking them up. (This is a somewhat gruesome method, however. It is not a pretty sight as the little buggers twist and writhe in agony. But quite satisfactory if they have been doing serious damage to your garden.) The salt, because it is used in negligible amounts, does not harm your garden.

    PREVENTION

    The primitive plant "horsetail" (Equisitum arvense), which grows wild throughout most of North America, contains sbstances that repel slugs. The recipe for making this solution follows:

    Place 1-2 ounces of the dried herb in a pot with a gallon of water. Bring the water to a boil, then simmer for 20 minutes. For extra punch add cayenne peppers to the pot. Cool the solution and strain; Then spray on vulnerable plants.

    BARRIERS

    British research indicates that aluminum sulfate, which is used to acidify the soil, is also a very effective repeelent for slugs. Work it into the soil, applying about 1/2 pound for every 100 square feet of ground. In this quantity it will not affect the pH of the soil very much, but will repel slugs. For a quick application, sprinkle a small handful around the base of a vulnerable plant. You will need to reapply after a heavy rain.

    Another barrier, this one for raised beds, is copper flashing. Tack a 2 inch strip of copper around the outside, about 1 inch from the top of the bed. The reason that this works is that copper always carries a very mild electric charge, undetectable to us, but it gives a little jolt to slugs.

    Another barrier for boxed raised beds is hardware cloth. Tack hardware cloth with sharp points onto the outside of the box. Extend the hardware cloth about 2 inches above the boards. Slugs are unable to crawl over this little fence.

    The sharp grains of diatomaceous earth will cut the soft bellies of slugs. Spread it around vulnerable plants. You'll need to reapply it after a rainfall. Eggshells work in the same way as diatomaceous earth. Spread crushed eggshells thickly around vulnerable plants. Sand, on the other hand doesn't bother mature slugs and snails. However, it does irritate baby slugs. Spread sand as a barrier early in spring when slugs are tiny.

    Slugs and snails seem to be repelled by seaweed. Rinse the seaweed with fresh water and spread it around susceptible plants, or around the outside of your flower beds. A side benefit of using a seaweed mulch as a barrier is that it also adds nutrients to the soil as it decomposes.

    If slugs and snails take a liking to your shrubs, trees, or vines, try applying a 3 inch wide band of Tanglefoot or a similar sticky substance to the trunks and stems of vulnerable plants.

    Wood ashes act as a barrier to slugs and snails also. Sprinkle two handfuls of wood ashes around the base of each plant when the plants or vines are about 4 to 5 inches tall. Or you can dig a trench a few inches deep and 3-4 inches wide. Fill the trench with ashes. To prevent damage to your plants avoid piling ashes right against the stems, and don't get any ashes on the leaves. Wood ashes can also have a very dramatic effect on soil pH and nutrient levels, so use sparingly.

    ANIMAL PREDATORS

    Downy woodpeckers, robins, and other garden birds are happy to bite into a nice juicy slug. Spread cracked corn and sunflower seeds to encourage birds to feed there, and to avoid adding weeds to your garden as could happen if you were to use other types of seed mixtures.

    Garter snakes are also important predators. If you use black plastic, they will crawl under it and eat up all the slugs and slug eggs. Some other slug enemies include: grass snakes, salamanders, shrews, toads, and turtles. Ducks will also eat slugs.

    INSECT PREDATORS

    Some insect predators of slugs and snails include black rove beetles, centipedes, firefly larvae, ground beetles,and soldier beetles.

    OTHER PREVENTIVE STEPS

    One of the surest ways to control slugs and snails in your garden is to prevent nitrogen deficiencies in your plants. Slugs prefer to eat soft, slightly rotting leaves. When plants are deficient in nitrogen, their lower leaves turn yellow and gradually decay, making them quite vulnerable to slug attack. Keep your plants well fed. If they look a bit undernourished, give them a quick boost with manure tea.

    Finally, eliminate hiding places. Slugs live and breed in cool dark places such as under boards, under leafy groundcovers, in weedy patches, and among rubble. Consider removing mulch on garden paths, the boards around raised beds, and other such potential shelters.

    Good luck and happy gardening.

    I've been having some puter problems this past week so I've gotten a bit behind in responding to questions and problems sent to me by my Garden Friends. Hopefully they are resolved now. My sincerest apologies to those Friends who have by waiting to hear from me.

    Here goes. Garden Friend Cheryl suggested that I talk about compost. Because that is such a vast subject, with so many options, I have decided to make that a topic for future discussion, after I have done some research.

    Cheryl's question was about very old lilac trees and how to care for them. My advice is to do only minimal pruning of new shoots and removal of broken branches, and otherwise leave them alone. They have survived for 100+ years and apparently are doing quite well. I don't know if Cheryl's Lilacs have only a single trunk or are more bush-like in appearance. My own venerable old lilac tree, also 100+ years old, has a single trunk. All I do to this old specimen is prune away any new shoots that appear each year and to check for any broken branches that might have resulted from heavy snow loads or strong winds. I don't even remove the old flower heads when it finishes blooming. I find that loving neglect works best for these old trees. My younger, newer lilacs, on the other hand, receive much more attention. What I do to, and for, them will be reflected when they, too, become venerable old trees, many years from now.

    On the other hand, if Cheryl's old lilacs are more the bushy type, and are taking over her Garden, my advice would be to prune away most of the smaller, newer growth around the base area until she is comfortable with their appearance. This is a trial-and-error method, and depends on the eye of the beholder. I have a sort of rule that I go by whenever I use this method. If I feel unsure about removing it I leave it alone. I can always go back and remove it later, after I've thought about it for awhile. Remember, once you cut it away, it's gone. You can't put it back. So my rule for pruning is don't cut it away unless you are absolutely sure that you want it gone. Use prudence when pruning.

    I hope that this has been helpful, Cheryl. Let me know how it turns out.

    My next topic is from Franc, who wants to plant crocuses in his lawn and is concerned about how the use of weed killers will affect them. Generally speaking, Franc, most herbicides (weed killers) are non-selective, which means that they will kill everything that they come in contact with. So, if you use herbicides in the area where you plant crocuses they will die, unless you use precautions. If you plant crocuses in only a small area of your lawn you can cover them with a tarp or plastic sheet before you use weed killer on the rest of the area. This should provide adequate protection for them as long as you are careful. If you plant crocuses throughout your entire lawn area then you might try covering each individual plant with a plastic pot lined with a plastic bag. This may be difficult to do, however, if you don't remember where each plant is.

    Remember, herbicides should only be used as a last resort against persistant weeds, and then only to spot-treat. If you must use an herbicide, choose one that is less toxic and as environmentally friendly as possible. Personally, I dislike using herbicides. I try to use alternative methods as much as possible, such as pulling by hand, planting ground covers, mulching, and, sometimes, deciding that I can live with a few uninvited species.

    If you must use weed killers, two that are less harmful to the environment are Glyphosate and superfast. These should be available at your local garden center. Please keep in mind, however, that I am not endosing or recommending either of these products. I have never used either one. I incude them only as another possible solution to your problem, Franc. Glyphosate, in the soil, is broken down by microorganisms into carbon dioxide, nitrogen, phosphate, and water. It does not leach through the soil into the ground water. Superfast is made of soap-based fatty acids, which dry out the plant quickly. Treated plants lose their moisture within a few minutes and die within hours. It breaks down on the plant. Both of these weed killers are reputed to be safe in the environment, but I am a sceptic by nature. A word of caution, Franc. Read the labels carefully, wear the proper protective clothing and equipment, and apply them strictly according to the instructions on the labels.

    Try the alternative methods of weed control first, Franc, and use the chemicals only as a last resort. A few "weeds" in your lawn may be worth the beauty of crocuses in the springtime. Best of luck to you.

    The next topic deals with pruning clematis vines. Jessica has two 12x12 trellises covered with clematis vines and wishes to know how to prepare them for winter.

    Well, Jessica, here goes. Clematis are generally divided into three groups depending on when they bloom. Since I do not know which type you have I will cover all three.

    The first group produce flowers early in the season on stems that have ripened during the previous season and need no routine pruning. However, if they become too vigorous or grow in a tangled, thick mass they can be pruned shortly after flowering to keep them in check.

    Newer cultivars (developed in recent years) that produce large flowers early in the season on the previous season's growth should be lightly pruned in very early spring before the plant starts to grow. The object is to remove straggly, diseased, or dying stems. Then cut back the remaining stems by about a third, to just above a healthy pair of green buds. The stems that grow from these buds will provide the first flush of blooms in the coming season.

    Hard pruning is used on those clematis species and cultivars that produce flowers late in the season on the current year's stems. In early spring, before the plant starts to produce new shoots, all of the previous year's growth should be pruned back to just above the lowest pair of strong, healthy buds (about 6 to 12 inches above ground level). As new growth develops, tie it to the trellis at regular intervals into the shape that you want. Be careful when you do this, however, because the new stems can be very brittle.

    Check the trellises at the time you do the pruning, cleaning and repairing them as needed. I hope this addresses your questions, Jessica. Best of luck to you in your new yard. May you have many hours of pleasure and enjoyment in it.

    I also heard from Debbie, who lives in Zone 5. Hers is a rather unusual problem. Someone gave her several flats of pansies just this past week (mid-November) and she tells me that she is not sure what to do with them. Well, Debbie, unless you have access to either a hot frame or a greenhouse there is not much you can do with them. You have simply run out of growing season for them. I, too, live in Zone 5, on the western shore of Lake Michigan. Winter comes early, stays around too long, and spring is usually cold and wet, so I know what you are going through.

    Pansies, one of my favorite flowers by the way, are considered annuals. However, they are self-seeding and will continue to grow for years if undisturbed. Unfortunately you need an entire growing season to get them to this stage. Here in Zone 5 we are fresh out of growing season.

    However, if you have the space in your garden you could cheat Mother Nature by constructing a hot frame and growing them inside. Simply put, a hot frame is a wooden box with no bottom and a glass top. It's sort of like a small greenhouse and it protects plants from cold temperatures. The top can be propped open during the daytime when the sun is shining to prevent excessive heat from building up inside the frame. If this is a possibility for you, Debbie, check your local library for books that give more detail on constructing hot frames.

    If this is the course you chose to take, Debbie, let me know how it works out. I've never had this particular experience and I don't know anyone who has either. So this could be a case where the student teaches the teacher, so to speak. Good luck to you.



    NormGnome's Garden

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