Applying botanical insecticides, horticultural oils, and insecticidal soaps to your plants can deter hungry insects. For more detailed information, read the articles Insect Management in the Home Garden and Natural Products for Insect Pest Management. If you need help choosing the right treatment for your plants or locating the recommended products, contact your county Extension office.

It could be a lack of humidity that is the cause. Try using a humidifier if you live in a drier part of the world. Also, check for pests carefully. Sometimes, believe it or not, if the leaf isn't broken too badly you can use some scotch tape to hold it in place until it's time for it to naturally die back. I can't promise this will work but I have done it and it did work. If the leaf is too badly broken there may be no hope. Don't cut it back. Wait for it to do what it needs to do by itself.

Two Possibilities: Citrus Leaf Miner Damage - This insect is the maggot of a tiny fly that lays eggs into the leaves. Maggots hatch from the eggs and "mine" their way through the leaves causing them to cup and crinkle. "Squiggly" lines can also be seen in the affected leaves. This insect is not harmful to the health or fruit production of established trees. Young citrus trees may benefit from sprays of horticulture oil which interfere with the fly's ability to lay eggs into the leaf.

Citrus are usually fertilized three times a year - Valentine's Day, Memorial Day and Labor Day. newly planted trees do not need fertilizer the first 1-2 years. Use Ammonium Sulfate, Ammonium Phosphate or Citrus Food fertilizer. The amount of fertilizer need per year depends on the age, the size, and the type of tree. For example, a medium-sized adult tree 5-6 years after planting needs 6.2 pounds of Ammonium Sulfate per year (split into three applications).

Thrice is nice. That's the recommendation on a bag of citrus fertilizer from Arizona's Best. And it makes sense if you think about it. First feeding comes near the end of winter which means February while the tree is somewhat dormant possibly looking a little under the weather because of a number of unexpected freezing nights so the leaves look a bit dried and discolored.

Leaves curl up at the margin and tip in an attempt to retain water. If they are curling up, this would indicate slight environmental problem: Either your light is a little too close to the plant or your oscillating fans are drawing too much moisture from the leaves. To remedy this problem, move your light up and make sure oscillating fans are not blowing too heavily on the leaves.

The trees should be fertilized at least three times a year in October, February and June. For any type of citrus, measure the circumference at the base of the trunk and calculate one pound of citrus fertilizer for every inch measured. Then divide this amount into three applications. Keep the area underneath the tree clear of all grass, weeks and mulch.

No, only trees that are stressed for various health reasons (for example, fungal disease or drought) will turn colors first.

Normally the arc plasma that occurs between the two electrodes of a lamp is approximately a straight line. When curling occurs the arc plasma instead of being a straight line forms a helix around the inside surface of the lamp causing the lamp to curl. The resonance that typically causes this curling effect occurs at arc lengths of 42", 55" and 77" for 50Hz and between 38" and 42"for additive lamps. Systems with these arc lengths should be avoided if possible.

The general rule for pruning citrus trees is DON'T. Only prune dead or crossing branches and a wayward branch. Do not prune in the summer, you could leave branches or trunk exposed to the sun which may cause sunburn. Never prune more than 15% at one time.

The more tropical citrus fruits like Key Lime, Tahiti Lime and Pummelo, all the other citrus varieties do well but are more cold hardy. On oranges, you may not get good orange color because of the lack of cool weather, but the fruit is fine. The most important factor when selecting a citrus for your yard is the root stock - use lemon types (rough lemon and macrophylla are the best) for our alkaline soils.

Since this site talks about conifer trees, we don't usually answer questions about deciduous trees. However, this is a question we get a lot! You may know that the green of deciduous leaves comes from the chlorophyll that is needed to make food for the tree. What you may not know is that there are other colors "hidden" in the leaves. They are hidden in the spring and summer because the chlorophyll is busy doing its job and the green color sort of takes over.

There are a lot of trees here on Vancouver Island although the majority of them are second or third growth. The loggers have raped and pillaged the forests here and even when city folk move out into the country the first thing they do is clear at least a 30m square piece of land to build their house on. Then they build a concrete foundation and up from there. The destruction mounts quickly. I wanted something different.

Symptoms on leaves and fruit are brown, raised lesions surrounded by an oily, water-soaked margin and a yellow ring or halo. Old lesions in leaves may fall out, creating a shot-hole effect.

Sooty Mold - Appears as a black, sooty growth on the upper side of leaves. Is harmless, but indicates that an insect was or is present (usually aphids, whiteflies or scales). Whiteflies. As these piercing-sucking insects feed on the undersides of the leaves, they secrete a sticky, clear fluid that drops onto the leaves below. Sooty mold grows upon this secretion. Sooty Mold Water or Varietal Problem. The problem of splitting fruits usually occurs in the early fall.

Chewing insect - Usually either a grasshopper or caterpillar. Damage is usually contained to a small proportion of leaves and should be ignored. The caterpillar is called an Orange Dog, and is the larval stage of the beautiful Giant Swallowtail butterfly.

Spring is an ideal time to plant new citrus trees. Garden centers have a good supply to pick from, and the trees are ready to begin root and shoot growth. Make sure you give the new tree a sunny site and space the trees at least 12 to 15 feet apart. If you miss the spring planting season, don't worry. Container-grown trees are available year-round. They can be added to the landscape anytime.