Tulips - Common Tulip Pests

Tulips are very hardy plants but, like any, have a number of pests small and large that need to be guarded against.

Several bugs commonly infest tulips, not least of which is the common aphid. Green Peach and other types are typical. They're white to greenish and about 1/8 of an inch long. Because of their color and small size they can be harder to detect, especially since they tend to hang out on the undersides of the leaves, where we often fail to inspect regularly.

Aphids feed on the leaves, sucking the juices out and causing them to curl. The flowers become deformed. They can also transmit viruses, as well as secrete a substance that attracts ants.

Fortunately, aphids are relatively easy to manage. They can be killed with a simple spray of malathion or rotenone. Some organic gardeners prefer a dilute nicotine sulfate, but this has to be used with care since nicotine is toxic to humans. For those who want to play it really safe, short term treatment is possible simply by spraying the underside of the leaves with water. Hose pressure is enough to remove them.

Japanese beetles are another common invader. They're about 1/2 inch long and have a kind of shiny brown color. They chew on the leaves, producing irregularly shaped holes that are characteristic and easy to spot. They tend to be more active on warm and sunny days, which tulips really like.

Spraying the plant with malathion or methoxychlor will kill even heavy infestations. When the problem is milder, it's possible to deal with it by simply knocking the beetles off by hand into an empty coffee can filled with water. Special traps are available as well. They're effective, but only at ground level. If the beetle bypasses it and makes it up the stock, it's necessary to employ one of the other methods.

Wireworms are occasionally a problem for gardeners who love to cultivate tulips. Long, segmented larvae are light brown to yellow and may be up to 3/4 inch long. They're the offspring of click beetles and they're a little harder to deal with since they live in the soil. Even inspecting the soil may make them hard to see, since they're down near the bulbs where we're naturally reluctant to go digging.

Wireworms feed on the bulbs, which damages the plant of course. Worse, they burrow into the bulb and travel up the stem, feeding there, too. That quickly kills the plant if there is any number of worms. Even one can do considerable damage. Evidence of an invasion may become obvious too late when the stalk falls over.

Dusting with chlordane, then working it into the top six or eight inches of soil, will kill wireworm larvae. Doing so before planting the bulbs is best. The bulbs themselves can also be dusted without harm. Developing plants can also be sprayed with malathion.

Slugs are another creature that can be found on the surface or just under it. Evidence of their presence can be seen in the silvery slime trails they leave. They can be anywhere from 3/4 inch to 2 inches or more. They feed mostly at night so you may wake up to tulip damage before you know they're there. But you won't miss the ragged holes they produce in leaves near the ground.

Spraying young plants with metalhyde or sprinkling some pellets around will keep the problem at bay. For those adverse to using artificial chemical control on plants, a bowl of grape juice left on the ground nearby may lure them away. Spreading a barrier of coarse sand around may also provide some protection. Salt dries them, of course, but it tends to dissolve into ground where it's harmless to the slug but may be a problem for the plant.

Larger pests, like rabbit and deer, can devastate a tulip garden. Physical barriers are the only effective means of keeping them at bay. Chicken wire around the base of the garden, even protruding a few inches below the surface can help.