Questions and Answers: Pests and Insects

• Can you give me some tips on controlling insects on indoor plants?

  First, carefully examine new plants to be sure they are insect-free before bringing them home. Isolating a new plant for a month before putting it with your other plants is good. Always use sterilized soil for potting. Take your plants outside about every two weeks and spray them with a forceful stream of room-temperature water. Do tops and bottoms of leaves to wash off bugs. Inspect your plants on a constant basis, and if none of this helps, use a solution of soap and water (two tablespoons to one-gallon water) and spray them. Make certain the soap does not contain degreaser.

• I see butterflies occasionally passing through my yard. What can I do to make them stay?

  Keep an area of your yard mowed, since butterflies are most active in open areas. Plant lots of flowers that provide nectar and plants that are considered larva or caterpillar food. Butterflies need a place that is kept moist. Nightly roosting shelter can be provided by planting vines or shrubs. Some species like rocky areas to rest on. A feeder can be made by placing rotting fruit or tree sap on a plate.

• How can I tell the good bugs from the bad ones?

  There are many excellent identification books on the market. A good book will have lots of pictures, plus a description that includes the areas they are most likely to be found, the different like stages and what they eat. With a good book and a little practice, you should be able to tell the difference between the most common and beneficial bugs.

• I have seen a few lovebugs, and I am concerned. Do they bite? Are they destructive?

  Lovebugs are harmless. They do not bite or sting, however, when they are hit by your car, their fatty remains can permanently destroy the finish, if they are not removed in a day or two. You can purchase a bug screen to cover your grill. You can travel at night or before 10 a.m. Some people spread a thin film of Baby oil on the hood, the bumpers and above the windshield. This does not keep them away, it just makes removing them easier.

• I have mole tunnels all over my yard. I don't believe in killing any animal. Is there something I can do to keep them form tunneling to my garden?

  When you see their tunnels headed for your plants, you can put garden stakes through the tunnels and put empty plastic jars on them. Place these noisemakers at regular intervals. The bottles move when the wind blows, making noise, which frightens the moles away. Use peanut butter or relish jars, not soda bottles.

• I found some very small worms on my fennel and was going to kill them when my neighbor told me not to. She said they were the first instars of butterfly caterpillar. What are instars?

  Instars are the stages a caterpillar goes through. They go through four to seven instars before they change from a caterpillar into a pupa. The caterpillars will devour your fennel before they change, but they will live only a few days and usually leave enough of the fennel for it to survive and grow. If you want both fennel and butterflies, buy more fennel plants than you think you will need.

• The center of my African violet is dwarfed, furled and puckered. What is causing this to happen?

  The mite that caused this is too small to be seen with the naked eye, but the skeletons are cast off and can be seen as a gray powder resembling ashes. This is the fearsome pest called cyclamen mite. The best thing to do is to remove three of four leaves for rooting, and destroy the rest of the plant. The leaves for rooting should be dipped in a weak solution of dimite before rooting. Kelthane and cythion are also good miticides. These little mites are transferred from plant to plant by arms and hands (especially sleeves).

• What are some ways to control pests on plants?

  The easiest non-chemical way is to use a forceful stream of water. Insecticidal soaps and horticultural oils are good, also. Remember, don't use oil in hot weather or you'll burn your plants and shrubs. Bacillus theringensis (B.T.) is great for caterpillars. If you elect to use chemical sprays, make sure you use the insecticide that is recommended for the plant you have, as well as the pest you have. Only use the amount recommended: More is not better.

• What insects are best controlled by systemic insecticide?

  Small-sucking insects such as aphids, whiteflies, scale, mealybugs, spider mites and lacebugs.

• I have fairly large mounds that run like a snake. Are they moles?

  It sounds like moles, and they're most likely feeding on grubs and insects in your lawn. If you get rid of the insects, the moles will leave.

• How do I keep squirrels from getting to a birdhouse mounted on a pole?

  Make sure the pole is not near a tree, bush or anything from which the squirrel can jump. Also, there are squirrel-proof baffles that you can purchase for the pole.

• What is dormant oil and when should I apply it?

  It's a miscible oil, a safe, easy to use, and very effective insecticide that no bug can develop an immunity to. Its mode of action is very simple. As you spray your plant, preferably from the top down, it coats the twigs and branches, running into little crevices in the bark, quietly smothering any overwintering insect eggs. The eggs cannot get air, they do not hatch and viola! You have just eliminated preexisting problems.

• My camellias have a white cottony stuff on the underside of the leaf. The leaves have a yellow discoloration. What is my problem?

  This is an insect called Tea Scale -- the worst pest on camellias. Oil sprays which suffocate the insects or systemic insecticides are recommended.

• My gladiolas bend over. Sometimes the weight of the flowers is responsible, other times they just seem to bend?

  Use a stake and tie them up. Use strips from old pantyhose, as this will not hurt the plant. You can also put horizontal latticework behind them to "prop" them up.

• I was given some kalanchoe plants. Are they houseplants? Can I use them in my yard?

  Kalanchoes are a herbaceous perennial that can be used as ground cover in a frost-free area. They can be used in planters and in rock gardens. In Kalanchoes blossfeldiana, the flowers are showy terminal clusters that bloom in the warm months. Several kalanchoe species grown in Marion County. You can pot them and bring them indoors for the winter, if you like. They are related to the jade family.

• My window boxes are looking rather worn. The flowers are still healthy, but they don't have the spark they did when I first planted them. I really don't want to replace them. What can I do?

  One a week, add some liquid fertilizer, Be sure to remove all spent blooms, yellowed leaves and scraggly branches. This will help keep you planting lush.

• My fresh-cut flower bouquets do not last long. The water gets smelly and the plants rot. What can I do to prevent this?

  Remove all the leaves on the stem that might be under water. Give the flowers fresh water every other day. Trim the stem every few days.

• What is causing the buds on my hibiscus to drop off without opening?

  There are a number of things that could be the culprit, such as thrips, caterpillars or nematodes. It could be a deficiency or overabundance of nutrients, or it could be caused by poor drainage, too much water or too little water. Examine your plant and the area for any of the above. If none of the above exists, be comforted in that it is the hibiscus' nature to prematurely drop buds, especially the doubles. Some varieties will do well for only a portion of the year. During excessively hot and dry weather, bud drop is often caused because the plant is not able to absorb the water it needs to compensate for the water lost through transpiration.

• The center of my African violet is dwarfed, furled and puckered. What is causing this to happen?

  The mite that caused this is too small to be seen with the naked eye, but the skeletons are cast off and can be seen as a gray powder resembling ashes. This is the fearsome pest called cyclamen mite. The best thing to do is to remove three of four leaves for rooting, and destroy the rest of the plant. The leaves for rooting should be dipped in a weak solution of dimite before rooting. Kelthane and cythion are also good miticides. These little mites are transferred from plant to plant by arms and hands (especially sleeves).

• Does poison ivy grow here in Marion County?

  Oh, yes, there is poison ivy here. You may not see trees covered with it as you did up north, but it is here. It looks like the plant you are familiar with, having the three leaves, and it definitely can cause a rash.

• My crotons have become tall and spindly and do not look nice at all. I really don't want to get rid of them, but they are not at all attractive.

  Crotons that have become too leggy may be "Beheaded" to force them to sprout lower. The removed heads can be used as cuttings to create additional plants.

• Last year, I had a problem with mildew on my zinnias. What can I do to prevent it from happening again?

  Don't water zinnia plants by top sprinkling. That increased the danger of mildew and fungus. Instead, water by flooding the ground. Occasional spraying with a fungicide is also a good prevention method.

• What do I do for my houseplants while we're on vacation?

  Depending on the type of plants. My first thought is to put them outside in an area with filtered light or partial shade. Nature does wonders for plants. Some people put them in the kitchen sink on a towel that is soaked in water.

• If I don't cut off the dead blossoms on my flowers, will the plants die?

  No, but you'll have less flowers than the plant would normally produce.

• How often should I inspect my plants?

  A good rule of thumb is to inspect weekly. Catching a problem early makes it much easier to treat. Check both the top and bottom of the leaves, and check the soil surrounding the plant.

• What makes some hydranges blue and some pink?

  The acidity of the soil causes the color difference. Blue is produced by acid, and pink by lime. Aluminum sulfate for blue and lime for pink.

• How can I get blue flowers on my hydrangea?

  The color of the non-white varieties of Bigleaf Hydrangea, Hydrangea macrophylla, is directly affected by the availability of aluminum in the soil. When the pH is between 4.5 to 5.5, an acid soil, aluminum is readily available to the plant and colors the flowers blue. Aluminum is locked up in alkaline soil with a pH of 7 to 7.5, so expect pink flowers. When the range falls between 5.5 and 7 the color varies from a washed out blue to a mauvish pink.

• Where can I get information on poisonous plants?

  Call the Master Gardeners at 671-8400. Also there is a bulletin, #175D, put out by the Florida Cooperative Extension Service, that is available at the County Extension Office. You must come down to pick it up, and it's best to call first to make sure they have it in stock.

• We have a border of very attractive, big, blue liriope. However, this summer it never really got green and lush, and there were barely any flowers. We pulled out a lot of brown blades from the center, but that didn't seem to help.

  To encourage lush liriope with a profusion of spears, early in the spring, cut the whole thing back to just above the ground with scissors, lawn mower or nylon edge cutter. In no time the plants will improve dramatically.

• My heavenly bamboo (Nandina) never seems to have many berries even though the plant is growing well?

  Either you are letting the plant dry out or it is getting too much nitrogen fertilizer. Water deeply during the dry season and reduce the amount of fertilizer. This plant usually does very well with little feeding. Even though Nandina does not have to be pruned, a light shaping in the winter will encourage berry production.

• How can I get my pineapple plant to produce fruit?

  Pineapple is a popular fruit and they can be grown outside in warm climates, especially in Florida. When you purchase your fruit from the grocery store and prepare it for eating, save the top with the leaves. You can grow another pineapple from this removed part. Here is how you do it. Secure a three-gallon pot. Fill it with a good potting mix and plant the removed top in the soil. The base of the removed top should be set in the soil about three or four inches deep. Water once a week but do not over water. Keep the soil in the pot moist. Pineapples are a member of the bromeliad family and too much water will rot the roots of the plant once they begin to grow. The plant will need to grow at least a year and a half or two years before it will produce fruit. When the plant is two years old place a whole apple down in the center of the plant. The gas released by the apple will stimulate the plant to initiate growth that will produce a fruit. Once the fruit is initiated it will take several months before it is ready to pick. Visit the web site listed below for other ways to force fruiting.

• How should I protect my tender plants from a late freeze?

  The most practical way for homeowners to protect their plants is to cover them. Cardboard boxes, blankets, newspapers, plastic, etc. can be used. The cover must extend all the way to the soil to trap the heat given off from the soil. Homeowners should not try to use sprinkler systems to protect plants. Home irrigation systems cannot apply enough water fast enough to do the job. Instead, more harm than good is usually done.

• When is the best time to plant or transplant my plants?

  Container-grown plants can be transplanted any time of the year. The critical factor is keeping the soil moist to prevent the root ball from drying out. To dig and move hardy plants that are growing in the landscape, it is best to wait until the dormant period between December and February. If the plant is considered tender to cold, it is best to delay planting or transplanting until after cold weather passes (March/April).

• When should I prune my plants?

  Pruning depends on plant growth and blooming habit. In general, shrubs and trees which bloom during the winter and spring should be pruned immediately after they flower. This type of plant sets its flower buds in late summer, so do not prune after August. Shrubs which bloom during the summer and fall produce flowers on the current season's growth. Therefore, the best time for pruning would be in late winter or very early spring before new growth starts to develop. Evergreen shrubs and trees which are grown primarily for their foliage may be pruned any time. Shrubs and trees which lose their leaves during the winter months may be pruned while bare of leaves.

• Should I mulch my plants?

  Mulching is considered a beneficial practice for all ornamental plants. Mulching conserves soil moisture insulates the soil (keeps it cooler in summer and warmer in winter) and suppresses weeds. Organic mulches such as shredded wood, pine needles or oak leaves are preferred to inorganic mulches such as pebbles and stone. The desired depth of the mulch is 2" 3" after settling. The area immediately around the stem of the plant should be left free of mulch.

• How often should I water my spring annuals?

  Plants need about 1" of water per week during the growing season. This can come from rainfall, irrigation or a combination of the two. This can be achieved by leaving a sprinkler on the plants for approximately one(1) hour. To check, bury a can at soil level and measure the amount in the cup after one hour. Then adjust time accordingly.