In the garden, a little knowledge can be very dangerous indeed. I vividly remember the day our neighbor complained that his vegetable plants mysteriously started shriveling soon after he sprayed them for bugs. I asked when he'd used that spayer before. "Oh, it was about a week ago," he replied. "I sprayed the grass for weeds.

Well it didn't take Isaac Newton to surmise what had happened. Our neighbor neglected to clean out his sprayer. Now the same chemical he had used to hammer his dandelions was stir-frying tomatoes.

All of which goes to show that when it comes to dealing with bugs, weeds, fungi, and critters, it's not enough to get most things right. You have to get them all right.

Each part of a well-designed landscape has its own function. The front yard reflects how you present yourself to friends, neighbors, and passerby. It should clearly guide guests to the entry. It should also anchor the house so it blends well with the natural landscape. The backyard–whether it contains a child's play area, a lush perennial border, a treasured collection of plants, beautiful garden accessories, or simply a comfortable sitting area–should be your private space. All houses need practical service areas where you can conceal items such as trash receptacles, potting benches, and tools. . Here, we will focus on the front yard. Not just this space but the plants that we suggest you never ever plant for reasons that Grumpy will tell you about.

Sometimes in order to get people to do something good, you have to make them understand what's bad. With that thought in mind, I've selected five of the worst things you can plant in front of your house. Some are ugly; some are monstrous; some get bugs and disease; and some manage to do all of these things.

Undoubtedly, some of you have these plants in front of your house and will shortly be greatly offended. That's OK. Feel free to make disparaging remarks about my worthless, parasitic cat. He won't know. He can't read (though he does watch TV). Kinda like Rick Sanchez on CNN.

Awfulest of the Awful -- Golden Euonymus


If you plant this in front of your house, you probably gave your girlfriend a pop-top for an engagement ring. I used to call golden euonymus a "gas station plant," until gas stations cleaned up their act and substituted plastic palms. Plants like this do nothing for the housing market. They are a sign that says, "For Sale by People with Absolutely No Taste."

So what's wrong with golden euonymus (Euonymus japonicus' Aureomarginatus')? Let me count the ways:

1. Mildew and scale eat it up.

2. The foliage often reverts to green, so you wind up with a bush that's half green and half yellow.

3. The garish foliage is about as subtle as a working girl's wardrobe.

4. Out-to-lunch people pair it with 'Rosy Glow' barberry, a look much favored by legendary garden designer Ernest T. Bass.

Awful Plant #2 -- Bradford Pear


Every Grumpian should have seen this one coming. I hate Bradford pear (Pyrus calleryana 'Bradford')! It's everywhere. Bragging about having one in your front yard is like bragging you have a toilet in your house. Bradford Pear is fast growing, easy to transplant, easy to grow, with showy spring flowers and spectacular red fall foliage. These attributes have led it to become one of the South's most overplanted trees. Lacks a central leader; main branches emerge from a common point on trunk, often causing tree to split in storms. Bradford pear grows much bigger than people usually envision: in 20 years, it can reach 50 feet high, 40 feet wide. Newer pears, such as 'Chanticleer' and 'Trinity', are better choices for most gardens.

This is why I despise it:

1. It gets too big for the average yard — 50 feet high and 40 feet wide. The only excuse for planting a row of them is if you're trying to block the view of a highway overpass.

2. Surface roots and dense shade makes it impossible to grow grass beneath it. Of course, if you've already blacktopped your yard, this won't be a problem.

3. Weak branching structure makes it very prone to storm damage. Photograph it when it's pretty. It won't stay that way long.

4. Its spring flowers smell like fish.

5. Although its flowers are self-sterile, they can cross-pollinate with other selections of callery pear, such as 'Aristocrat' and 'Cleveland Select.' When they do, they produce thousands of tiny pears, which give rise to thousands of thorny seedlings are are now invading the countryside.

Awful Plant #3 -- Redtip Photinia


Now I know what a lot of you are saying. "How can he hate such a purty plant? I love those shiny red leaves and the white flowers. What a churlish Grump!"

The popularity of Fraser photinia just goes to show that nothing succeeds like being obvious. A chance seedling discovered around 1940 at Fraser Nursery in Birmingham, Alabama, Fraser photinia (or redtip, as it is also known) displayed new leaves of bright red rather than the usual green. People flocked to buy it. Today, more homes probably have Fraser photinias than indoor plumbing.

Here's my beef with Fraser photinia (Photinia x fraseri):

1. Like Bradford pear, it's planted everywhere in the South. Find me a trailer park, parking lot, or chain-link fence without one. It's about as common as clipping your toenails during the sermon.

2. It grows fast and big — up to 15 feet tall and wide, much too big for the front of your house, unless you're hiding from the law. So you have to shear it often, which brings us to problem #3.

3. Most people grow it for the bright red new leaves that gradually turn green. The more you prune, the more red leaves you get. Trouble is, the new growth is extremely susceptible to a disfiguring disease, called Entomosporium leaf spot. Small spots appear on young leaves. As the spots age, the centers turn grayish with a dark purple border. Severely infected leaves drop prematurely.

The solution? The fungus that causes this leaf spot only attacks new, red growth. Mature green leaves are immune. Splashing water and wind spread the disease from leaf to leaf. To prevent it, remove and destroy infected leaves. Do not wet leaves when watering. Avoid summer pruning, which results in a flush of susceptible new leaves. Spray the plant with chlorothalonil (Daconil) every 10 to 14 days from bud break in spring until all new foliage has matured.

Unless you spray regularly with a fungicide, the disease eventually kills the plant — which, come to think of it, isn't so bad.

Awful Plant #4 -- Leyland Cypress


Very few people who plant this monster have any idea how big it gets — more than 70 feet tall and up to 15 feet wide. And because it can easily grow 3 feet a year, it doesn't take long to resemble a Saturn 5 rocket. Still, people love planting this thing on the corner of the house. The only house big enough for this is Biltmore. In recent years, Leyland cypress (x Cupressus leylandii) has come under widespread attack by a potentially fatal fungus, seridium canker, which often causes trees to gradually die from the top down. Drought stress favors development of this disease. Leyland cypress has become the South's number one choice for tall screens. Once established, it can easily grow three to four feet a year. Just remember, though, that it eventually grows 60 to 70 feet tall if unpruned.

Problem one with Leyland Cypress is called Seridium canker. Older interior foliage yellows, them browns. Twigs and branches die. Sunken reddish, dark brown, or purplish cankers form on the bark and ooze sap. Infection usually affects the lower branches first, then travels up the tree.

There is no chemical control for this disease. Avoid wounding the bark. Any type of wound provides an entry point for the seridium fungus. Prune out diseased branches, cutting 6 inches below the site of infection. Space plants adequately so that air can freely circulate among them.

Problem two with Leyland Cypress is needle or tip blight. During warm, wet weather the needles closest to the inside of the tree turn tan or gray, then die, leaving the inside of the plant bare while the outside remains green. Or needles on the tips of branches turn brown and die, and tiny black dots appear on dead needles and stems.

These problems usually affect plants growing too close together. The dense foliage restricts air circulation, so foliage doesn't dry quickly. This makes things easy for either of two pathogens – Cercosphora, which also causes needle blight on Japanese cryptomeria and related species; and Phomopsis, which also causes twig blight of juniper. To control these problems, space Leylands eight to ten feet apart. Avoid wetting the foliage.

Awful Plant # 5 -- Privet


I know a guy named Dr. Dirt who calls these shrubs "privy plants." He doesn't know how right he is. I'll admit that some of the broadleaf species, such as waxleaf privet (Ligustrum lucidum) and Japanese privet (L. japonicum) have some use in the landscape as limbed-up trees, but the small-leaf hedging types, such as California privet(L. ovalifolium) and Chinese privet (L. sinense) are absolute garbage that belong in a privy. Provet is a fast-growing plant often used in screens and hedges. Some species are invasive. Many people refer to privet by its botanical name, Ligustrum. A more accurate name is "Disgustum." How come?

1. In spring, privet produces white flowers, whose sickeningly sweet odor reminds me of the deadly dikironium cloud creature on "Star Trek." To be fair, the cloud killed people by robbing their blood of iron. Privet flowers just cause allergies.

2. The flowers give rise to hundreds of blue-black berries relished by birds, who spread them all over the universe. As a result, privets are incredibly invasive and weedy. Plus, they grow really fast and need trimming about every two minutes or they'll swallow your house and dog.

Now here's the weird thing. Of all the variegated plants in the world, I think variegated Chinese privet (show above) is one of the better-looking. In fact, it's perfect for next to your privy. But if I could snap my fingers and make all the privet in the world disappear, I would. I'd do the same for spammers.

A problem with privet are scales. White, yellowish, gray, reddish, or brown bumps encrust stems and undersides of leaves. Leaves yellow, brown, and then drop. Stems die back. These bumps are scales–sap-sucking insects that weaken the plant. Spray with horticultural oil, making sure to coat all leaf and stem surfaces. Or apply a systemic insecticide, such as acephate (Orthene).

Another problem is leaf spot. Irregularly shaped tan spots surrounded by dark brown border appear on leaf margins and at the tip. The spots become sunken with age. Caused by a fungus, leaf spot is unattractive but not life-threatening to the plant. Selectively prune (thin) dense hedges to improve air circulation through the plants. Avoid overhead sprinkling. Water plants early in the day to allow them to dry completely before evening. If practical, pick off and destroyed spotted leaves. On plants previously affected, spray new healthy leaves in spring with a Bordeaux mixture, chlorothalonil (Daconil), or maneb.

You can't blame everything that goes wrong in your garden on a bug, blight, or critter. Some things may be your fault. Seven other things to keep in mind:

1. Crowding plants. Jamming plants together may give your garden a mature look intitially, but it reduces air circulation around leaves and stems, promoting disease. And it weakens plants by forcing them to compete for sunlight, water, and nutrients.

2. Improper watering. If you really want to kill a plant, giving it too much or too little water is a great way to do it.

3. Nicking the bark. Barks works like your skin: It keeps good things in and bad things out. Accidentally wounding the bark of a shrub or tree with a string trimmer, lawn mower, saw, or hockey stick promotes ready access for insects, fungi, bacteria, and viruses.

4. Monoculture. This term means planting large numbers of the same plant close together. All of the plants have the same susceptibility to certain pests. So if those pests show up, instead of one or two plants dying, all do.

5. Overfeeding. Giving a plant too much food, particularly nitrogen, encourages lush, soft growth that insects and diseases relish.

6. Topping trees. Read our lips. Topping trees is always a bad idea. It not only ruins their appearance, but also makes them prone to insect and fungi attack, as well as storm damage.

7. Scalping the lawn. So think cutting the grass down to the soil line means you won't have to mow it often? Well, you're right, because doing so repeatedly weakens the grass so much it might die. Unfortunately, the weeds that soon replace it like close cutting. So you'll end up mowing those instead