By STEVEN WITHROW

Many of us do not like to find spiders and other bugs in the house—but are we too quick to get rid of them? Are there “good” spiders we should leave in peace?

And what about certain plants outside? Few people are fond of poison ivy, oak and sumac, for instance. What can we do to discourage their growth while protecting the plants that attract butterflies and bees without using herbicides and insecticides?

Here we look at the span of which species are benign, if not desirable, and which are clearly unwelcome.

Sparing Good Spiders 

First, let us acknowledge that there are types of arachnids that are harmful to humans, as their venomous bites can cause tissue damage. The brown recluse, black widow and northern black widow are examples. They help give the word “arachnophobia” its fearsome power.

Spiders will bite if they feel threatened, and spider venom causes a variety of reactions, including a stinging red mark, localized swelling or an injury requiring hospitalization.

However, most spiders we find on Cape Cod are harmless and, in fact, beneficial to people. They should be spared the vacuum or an insecticide, many insect experts say.

“Spiders feed on common indoor pests, such as roaches, earwigs, mosquitoes, flies and clothes moths,” a Bayer CropScience fact sheet explains. “If left alone, spiders will consume most of the insects in your home, providing effective home pest control.” By eating fleas, mosquitoes and cockroaches, spiders help limit the spread of diseases.

Spiders also kill other spiders. For example, the long-legged cellar spider is known to kill the black widow.

With a two-year average lifespan, spiders typically reproduce in spring and their young mature in summer.

Here are three ways to minimize the number of spiders in your home without using an insecticide: First, block points of entry for spiders and other insects, focusing on doors and windows, removing any cobwebs you find. Second, keep firewood and debris away from your house. Third, store seasonal clothing in plastic tubs with tight-fitting lids.

Attracting Pollinators

Bees, butterflies and hummingbirds are among the animals that are essential for pollinating plants. 

Unless we plan to hand-pollinate, we need bees for growing vegetables, crops such as melons and squashes, and tree fruits such as apples, among countless other examples.

To create a pollinator-friendly garden, many experts recommend choosing nectar- and pollen-rich plants such as wildflowers and a succession of blooming annuals, perennials and shrubs. Also, butterfly larvae feed on plants such as dill, fennel and milkweed. Pollinator gardens can be of any size and can thrive in cities, suburbs and rural areas.

To reduce the potential dangers of pesticides—including those labeled “organic”—experts recommend applying pesticides carefully and selectively, avoiding using chemicals on open blossoms or when bees or other pollinators are present. 

Pollinators need shelter from predators and the elements and to raise their young. A wild-growing hedgerow is beneficial for ground-nesting bees, for example. Installing a water garden, bird bath or catch basin for rain is useful.

Putting up a hummingbird feeder or nesting box, although it can attract squirrels, is an excellent way to attract these beautiful, helpful birds to your yard. 

Some experts also recommend learning about backyard beekeeping—a hobby that can be practiced even in small outdoor spaces. 

Plants that attract butterflies and caterpillars include aster, bee balm, borage, buddleia, calendula, daylily, delphinium, dianthus, fennel, goldenrod, hollyhock, lavender, lupine, marigold, milkweed, nasturtium, nettle, oregano, phlox, purple coneflower, Queen Anne’s lace, thistle, verbena, willow, yarrow and zinnia.

Plants that attract hummingbirds include begonia, canna, columbine, dahlia, foxglove, fuchsia, geranium, gladiolus, impatiens, iris, lily, paintbrush, petunia and salvia.

Annuals and perennials that attract bees include allium, basil, bergamot, blanket flower, cosmos, goldenrod, helianthus, hyssop, joe-pye weed, marjoram, mint, mullein, poppy, rosemary, skullcap, sunflower, thyme, wallflower and wild rose.

Other Beneficial Bugs

In addition to pollinators, several other insect species are beneficial for gardeners. 

Lacewings are predators that feed on aphids, scales, thrips, mealybugs and caterpillars. They are attracted to sweet alyssum, coreopsis and cosmos.

Ground beetles dig into mulch by day and hunt slugs, snails, cutworms and other pests by night. To protect ground beetles, experts recommend planning perennials as a place for them to overwinter, making sure to provide enough mulch for the winter months.

Soldier beetles help control pests such as aphids and many types of caterpillars. They are attracted to goldenrod and catnip.

Adult ladybugs eat aphids, mealybugs and mites, and their larvae can help control an aphid or mite infestation. They are attracted to members of the parsley family: carrots, parsley, dill, fennel and yarrow.

Goats To Gobble Problem Plants

“Allow it to cool, then add eight drops of liquid dish soap and put the mixture in a spray bottle. You can spray the poison ivy or pour it directly on the plant. This will kill all vegetation, so be sure to apply it only to the poison ivy,” the site said.

Planting grass seed to grow a lawn will also limit where poison ivy will grow.

Another method of natural brush clearing and poison ivy control is to use goats, and Meghan J. Hanawalt of Falmouth is doing just that with her company, Get My Goats (www.getmygoatscapecod.com).

Foraging goats offer an alternative to pesticides or machinery to get rid of unwanted underbrush or pesky plants such as poison ivy, catbrier or bittersweet. Poison ivy does not affect goats as it does humans, causing a blistery rash. The reason is unclear.

When Ms. Hanawalt moved to Falmouth 15 years ago, she had to clear out large areas of poison ivy from her yard. She had concerns about spraying pesticide to kill the poison ivy growing back.

“I thought, ‘Why can’t we rent a goat?'” she said in an Enterprise interview in 2015. “We don’t want to spread poison. This is a much kinder way.”

“Goats definitely have preferences when it comes to brush clearing. Not all leaves are the same. Some don’t appeal, some are toxic and some are intoxicating. Poison ivy leaves are almost irresistible to them. The goats eat the leaves, and I remove the branches. No mess. No fuss,” Ms. Hanawalt wrote on her website.

Ms. Hanawalt’s Nigerian dwarf goats can eat through a 20-by-20-foot space in half a day.

Other companies include The Goatscaping Company (www.gogreengoat.com) in Plympton and and GOat Green Cape Cod (goatgreencapecod.wordpress.com) in Centerville.