Cedar trees, in their various forms, have become a popular part of today's landscaping, but caring for the trees can be more difficult than caring for some other trees because of the specific soil conditions that are necessary to maintain a healthy cedar tree. Cedars prefer slightly basic soil pH, so adding lime to the soil at the time of planting might be a good idea, just make sure the soil conditions are right.
Cultivated cedar can be grown in most climates, but in nature cedar trees prefer soil that contains lime, with a very neutral or even slightly basic pH. The trees need nitrogen, as most plants do, but do not require annual fertilization unless the foliage begins to turn yellowish. This may be an indication that the tree is not getting sufficient nitrogen. Creating more basic soil can help the trees absorb the nitrogen they need and stay healthier.
Many nurseries and farm supply stores will provide the basic materials for at-home soil pH testing or can offer references to regional laboratories that will analyze a soil sample. Before choosing to plant cedars it is always a good idea to have the soil tested and observe the natural groundwater patterns of the proposed cedar site. Cedars do not like standing water, so if the proposed site stays wet for more than two consecutive weeks in a year, install drainage before planting your cedars. The water drainage patterns will also affect the need for lime and fertilizer treatments. If the land stays wet or has an unusually wet season, consider retesting the soil sample to adjust your cedar care. When sending a sample to be tested, make sure the lab understands what you are planting so their recommended treatments are appropriate for your trees.
Some tree resellers are under the mistaken impression that the soil for cedars must always be treated with lime before planting. Others recommend annual application of lime to enhance the tree's growth. While it is true that cedar trees prefer slightly basic soil, annual treatment may be far more than your soil requires. Periodic soil testing can help you determine the frequency with which to apply lime or if it is necessary at all for your trees.
Cedars Add Acidity
The detritus, leaves and other materials falling off your cedar tree, can actually increase the acidity of the soil surrounding the tree. If you have a particularly heavy layer of detritus around the trees, consider raking the materials away from your cedar trees or using an agricultural lime to counteract the acid released into the soil as the detritus decays. Prevention is generally better than treatment, however, so removing the materials is a preferred option to lime treatment. If lime treatment becomes necessary, be sure to use the amount recommended via the local soil laboratory.
The two most common options for lime application are pulverized limestone and pelletized lime. Pulverized limestone, sometimes call chalk, is messy and dusty, presenting some hazard that it will blow or be breathed in while applying. Pelletized lime is a little more expensive, but spreads easily with the use of a lawn spreader. The pellets melt with rain or irrigation and the mess of adding lime is avoided. Soil testing will indicate how much lime to apply, but results are not instantaneous. Changing the pH level around your cedar trees can take up to six years. Lime is generally best applied in spring or fall, but can be applied year-round.