The fungal spores of mycorrhizal fungi are ubiquitous, which means they will colonize containers without our help so long as the cultural conditions in the containers and the symbiotic partner (plant/tree) are appropriate.

I do 175-200 repots each year, so I've had an up close and personal look at the condition of many thousands of trees. I find most of my trees show conspicuous visual evidence of their relationship with certain fungi from late fall through mid-late spring, then the fungi die during the hot months before returning again in Oct-Nov.

Mycorrhizal fungi relationships aren't necessarily all on the upside. The relationship reduces the amount of rootage a plant needs, so if anything happens to cause the fungi to lose viability under conventional container culture, and that can occur for a variety of reasons, the plant is suddenly left with a root system ill-prepared to satisfy water/nutrient demands. Simply using a fungicide prophylactically can wreck the relationship in minutes.

If one follows the directions on a fertilizer label, there is very little chance that roots or foliage can/will be burned. Many times I've seen roots finer than a spider web strand clinging to controlled or slow release fertilizer prills in the grow medium. Any evidence of plasmolysis would be the result of grower error - applying too much at one time or watering in such a way that ensures a build-up of dissolved solids in the soil solution. Fertilizer instructions are always provided so the solution strength is will within the bounds of being safe for plants. I suppose what I'm saying is, if a fertilizer burns plants, it's not 'fertilizer error', it's 'grower error'.

@Soumil Yarlagadda asks: whats a good fertiliser regimen for these plants? I currently have Dyna gro foliage pro (superthrive) 9-3-6, but i havent used it yet. Any good fertilizer regimen must take into account the product being applied, the grower's watering habits, and the physical properties of the grow medium. Without that knowledge any advice offered wouldn't even rise to the level of a SWAG. You have chosen an excellent fertilizer product and it represents complete nutrition from a single package. Precious few fertilizers can make that claim.

A healthy root system is an absolute prerequisite to a healthy plant, and you simply cannot have the later w/o the former. You should be able to water a planting to beyond the point of saturation, at will, without having to worry that your soil will remain waterlogged so long that excess water in the soil will deprive the root system of oxygen, and in doing so limit normal root function and/or negatively impact root health. Water uptake (and therefore nutrient uptake) is an energy-driven process that must take place in the presence of oxygen, an element essential to the 'burning' of the plant's food (sugar/ glucose) that produces energy for roots' metabolic functions. If your soil is too water-retentive to water in this fashion w/o the plant(s) having to pay a saturation tax, you might want to consider a more forgiving soil, or learn some new tricks that limit how much water a water-retentive soil can hold. CAN hold is different than WILL hold. Ideally, you would be using a grow medium that passively allows enough water to drain from soils that you needn't worry about root function/health issues. If it doesn't happen passively, you should take the active role to MAKE it happen; or, be willing to accept the limitations and issues that accompany soggy soils.

If we can assume you're using a medium that allows you to water correctly, fertilizing is monkey easy. Just follow the fertilizer instructions and apply about every 3rd or 4th time you water in the summer, and every 4th or 5th time you water in winter. When you only water, drop a marble, button, .... in the pot. When it's time to drop in the 4th marble (if you're fertilizing every 4th time you water) fertilize instead and pick up the 3 marbles in the pot. By this method you can precisely monitor who needs fertilizer and when.

If you aren't using a medium that allows you to flush the soil w/o limiting root function or root health (due to long periods of soggy soil) fertilizing become little more than a guessing game. You'll never know what is available to the plant or the ratio at which the nutrients are unless you can flush the soil with regularity. The flushing eliminates build-ups of salts from tapwater and fertilizer solutions and prevents the ratio of nutrients in the soil from becoming badly skewed, which causes antagonistic deficiencies - occurs when too much of nutrient A affects/limits uptake of nutrient B and/or C,D,E ...... This is very common for growers forced to water in sips because their grow medium is too water-retentive.

Al