Answer: Citrus trees are sometimes a challenge in the landscape, so don't feel too bad about not providing exactly the right cultural and environmental conditions for your trees. They need full sunshine, moist yet well draining soils, and a regular diet of essential minerals. There is a functional balance between the above and below ground portions of the tree. This is referred to as the shoot:root ratio. It represents the balance between the amount of shoot the root system can adequately supply with water and mineral nutrients, and the amount of roots the shoot can support with organic compounds derived from the photosynthetic process.
As citrus trees mature the scaffold framework and foliage area become greater and the shoot:root ratio increases. As foliage is shaded out, defoliation can occur and branches and twigs may die. The development of a certain amount of such dead wood is natural in the normal development of a citrus tree, and represents the tree's ability to maintain the appropriate shoot:root ratio.
Excessive dead wood, particularly in the tree interior and base of the canopy, may indicate a need for pruning to allow the penetration of more sunlight to these parts of the canopy. Routine hedging and topping programs will help prevent the development of leaf and twig dieback in interior canopy locations. Excessive twig dieback on the outside of canopies may result from a number of factors which cause defoliation including freezes, drought, nematodes, decline diseases such as blight, root loss due to water damage, copper toxicity, greasy spot defoliation and spray burn, among others. Soil cultivation directly beneath the tree can sever surface feeder roots, and will sometimes lead to leaf wilt and twig dieback.
I'd monitor the water your trees are receiving. One deep soaking per week is all they should require. More frequent watering can keep the soil too waterlogged for healthy root growth. Try changing your watering habits and see if that doesn't make a difference later in the season.
Q&A Library Searching Tips