Solving Tulip Problems

Tulip Problems
SymptomProbable Cause
Bulbs Unearthed; Gnawed; Flowers; Foliage ChewedCritters
Spots on Leaves; Stems and FoliageEnvironment
Flowers and Leaves Spotted; Stems RotTulip Fire Disease
Foliage and Buds Do Not OpenAphids
Foliage Distorted; Bulbs DecayedBulb Mites
Southern Plants StuntedNeed Cold


Bulbs Unearthed, Gnawed; Flowers, Foliage Chewed by Critters
Rodents Unearth, Gnaw on Tulip Bulbs - During the winter small rodents such as mice, voles, and squirrels eat bulbs. Mice use abandoned mole tunnels to get at the bulbs. Squirrels dig them up when the ground is not frozen. If you have this problem, line each bulb planting hole with a small basket of 1/4-inch hardware cloth cut to fit. Or, try planting individual bulbs in tin can “sleeves” cut open at both ends and sunk into the soil so that the top rim is just covered by soil. Set bulbs near the bottom of the can to allow the roots to spread into the soil beneath.

Deer Chew on Tulip Flowers and Foliage
Whitetail deer absolutely love tulips. Discourage them by planting tulips in containers that you can bring in or cover when deer are about. Enclose tulip beds with an electric fence to discourage the occasional deer visitor. If you have lots of deer enclose your entire yard with black polynetting deer fence or do not grow tulips. See the file on Controlling Deer for more information about how to dope with this situation.

Spots on Leaves, Stems and Foliage Are Due to Environmental Problems
Frost Causes Brown Spots On Leaves, Stems - Tulips caught by late spring frosts may show small brown spots that later merge into blotches. Sometimes leaves split and look ragged. Prevent this by spreading a 2-inch layer of organic material such as chopped leaves on the soil over tulip bulbs in the late fall right after the ground freezes.

Calcium Deficiency Causes Watersoaked Spots on Foliage
Garden soils or soil mixes poor in calcium sometimes cause tulip flower stems to topple over and glassy spots to appear on stems and leaves. Remedy this by adding ground limestone to the soil, or spray growing plants with a 2% solution of calcium nitrate. When forcing tulips for use indoors, avoid overwatering and sudden temperature changes.

Flowers and Leaves Spotted, Stems Rotted Signal Tulip Fire Disease
This disease, caused by the Botrytis fungus, is a mold that induces blotching on a tulip's tissues and failure of its buds to open. Patches of infection distort stems, leaves and buds, sometimes showing a visible red tinge at the site of the partially dead tissue.
Suspect tulip fire if your bulbs have clusters of black, seedlike specks on them. Handle healthy bulbs carefully and in dry weather to prevent wounds or injuries that would invite this fungus. Dig out any diseased bulbs along with their nearby soil. Do not plant bulbs there again for awhile. This disease eventually occurs in soil where tulips are planted repeatedly. It dies out by itself if the soil is free of tulips for 4 years. It is specific to tulips, no need to worry that it will spread to other plants.

Foliage and Buds Do Not Open Due to Aphid Infestation
Aphids are soft-bodied, pear-shaped sucking insects, about the size of the head of a pin. They come in a variety of colors including green, brown, and pink. Tulip aphids cluster on leaves and shoots, preventing new growth from unfolding. Lily aphids occasionally attack tulips in greenhouses. The green peach aphid is not a threat by itself, but transmits virus diseases.

So, control any aphids by spraying tulips with a forceful stream of water to wash them away or spray them with an insecticide product featuring insecticidal soap as directed on the product label. For more information see the files on Controlling Aphids

Foliage Distorted; Bulbs Decayed Indicates Bulb Mites
Bulb mites, about 1/50 inch long, are barely visible. They have four pairs of legs, piercing-sucking mouthparts, and very compact bodies. Below ground, or while bulbs are in storage, mite infestations cause them to become hard and light chocolate-brown colored. Hundreds of mites feed on their dry and crumbly pulp. This damage also opens the way for other pests and diseases. Control mites by destroying all badly infested bulbs, and soaking other dormant bulbs for 3 hours in hot water (110°to 115°F) with some household bleach added prior to planting. For more information see the file on Controlling Mites

Southern Tulips Are Stunted Without Cold Treatment
Tulips grow well in the South, but they require a period of chilling which they do not get outdoors in the warm climate. Purchase pre-chilled bulbs, or give them a cold treatment of 8 weeks’ exposure to 40°F (the bottom shelf of your refrigerator works nicely) before planting them outside in late fall. This treatment ensures they will grow to their normal height.