Q. Last week we planted several fruit trees and have established trees as well. Would you recommend applying fertilizer around these trees now? Spikes or granular type of fertilizer? A. Fertilizers will benefit fruit trees the most if applied to the soil just before spring growth. But if you haven’t applied any, then do it now during spring growth.             The least expensive way is using granular fertilizers in a single application in the spring.             Fertilizer stakes or spikes are granular fertilizers compressed into a stake you can drive into the ground. They are not messy, convenient, and no open bags that can spill but more expensive per pound of fertilizer. Jobes does a good job with fertilizer stakes but a bit on the expensive side.             Drive them into the ground near drip emitters or in the irrigation basin; one for each emitter. They release nutrients slowly. Apply them only once in the spring. This is a cheaper version we were using at the orchard for trials. The soil should be wetted and the plastic cap put on top and the stake pounded into wet soil just under the emitter or in the irrigation basin. Small trees two will do. Larger trees would require four or more, one in each quadrant of the basin or under an emitter.             For new trees, if you mixed in good quality compost with the soil in the planting hole you can skip a fertilizer application this season. If you put a smidgen in the ground then apply a fertilizer now if you haven’t.             You can split granular fertilizer applications in half if you want. Apply half now and the other half after you harvest or in a couple of months if there is no fruit. Fruit trees that are tender to winter cold should not be fertilized after mid-summer so apply the second half earlier than this.             If you are using organic fertilizers that release nutrients slowly then apply it once in the early spring.  Young fruit tree fertilized with compost at the orchard. The tree is watered with an irrigation basin and a bubbler. The water from the bubbler moves the compost into the basin through the mulch. The compost acts like a “fertilizer tea”.             Foliar sprays of fertilizers are a great way to fertilize trees if they are in difficult places. Foliar applications should be done more frequently because their results are short-lived. Apply foliar sprays every 6 to 8 weeks until it gets hot.             Keep fertilizers away from tree trunks but in contact with water. Apply them no closer than a foot from the trunk and just under the soil surface. Make sure they are watered in thoroughly after application. Compost applied to the base of the fruit trees by volunteers at the Orchard. Two five gallon buckets are applied to each of the larger trees. One five gallon bucket for the smaller ones.             I have seen new trees killed by applications of fertilizers applied too close to the trunk. Salt damage from fertilizers can kill newly planted trees.             Don’t forget iron. Newly planted trees normally don’t need it the first couple of years but may develop iron shortages beginning in the third to the fifth years. This plum tree had iron chlorosis really severe after it leafed out in the spring. Four applications of iron sprays, spaced one week apart, turned it completely green again. Next year it received iron chelate applied to the soil in January to prevent this.