Do you have an easy recipe of making your own mix for a gardening-beginner? Yes. I would recommend using what is known around here as 'Al's 5-1-1 mix' for annuals and perennials grown for just a year or two before being repotted. For plants that will stay in the same container/mix for more than 2 years I would recommend what is known around here as 'Al's Gritty mix'. The 5:1:1 mix is 5 parts pine bark (very small pieces), 1 part perlite and 1 part peat. The gritty mix is 1 part pine bark fines, 1 part Turface MVP and 1 part grower grit (#2 sized). For more information on this I will refer you to this thread. Don't get too hung up on specific ingredients and percentages. The principle is using ingredients that will be of a large enough size (above 1/16th inch) for as long as the plant will be in the mix. This provides superior aeration. The higher the percentage of organic matter such as peat or bark, the faster the mix breaks down and aeration suffers. The bark breaks down much slower than peat though. Anyway, read the thread and you will learn a lot. If you can't find suitable ingredients to make your own mix in time to get the season started then just get the regular MG potting mix and take until next year to learn more and locate sources for ingredients you want.

The reason you can't trust the volume of nursery pots, Jim, is that those black nursery containers are all "nominal" sizes. That means the volume of the pots is vaguely related to the stated gallon size. A "5 galllon" nursery can is 10.5 in. diameter and 12 in. tall. My online calculator says that is only 3.75 gallons if you pot 2 inches from the top of the pot. That isn't large enough for any rose past the first year or so if it puts on vigorous growth. The foot stomping is an old landscaper practice. It's just a cheap way of determining settlement without taking the time to water a plant in. I wouldn't do it. Water your plant in to settle the soil. I've seen people planting roses into dry potting soil. I wouldn't do it. Many potting soils have peat moss which sheds water once dry. Those of you in climates with steady rain year round may not have this problem, but in the desert West, once peat dries out, it takes a concerted effort to dampen it. I open the bag of soil, stick the hose in, fill it up and mix. Then I pot with dripping wet potting soil and also water it in. It's mud pies for grownups. It assures that the soil comes to the optimal height in the pot (about 2 inches down) and fills major air pockets. I unpot roses all the time and have never found an air pocket. I don't drop pots on purpose. Our summers are too hot to grow a lot of roses in pots well. We can't keep the roots cool enough through June and July. I overpot extensively. A 3 x 3 rose goes in an ornamental pot that is 22-24 inches high. I use various decorative pots from the big box store and always buy the biggest size. Why? They bring to rose up to height and look more in scale with a landscape. It's funny how a pot looks big in a store and miniature in the garden. Also, with those big pots I'm approaching the 15 gallon actual size I find any healthy rose needs. I do a seat of the pants volume-of-cone calculation to guesstimate the volume of the pot, taking into consideration the potting soil is probably 3 inches from the top of the container. Here's a nice online volumetric calculator. http://www.online-calculators.co.uk/volumetric/conevolume.php

Gudang, a lot of people here on this forum started with a heavy dense soil mix, often with compost and other soil components - because that is what is commonly available. Then they noticed that their plants are start to suffer at one point and came here for advise. Al (Tapla) has relentlessly taught the concept for better soil mix, fertilizing, pruning, repotting and many other topics. Most made an effort to follow in his foot steps and found his teachings to be invaluable and succeeded in keeping their plants flourishing. In short, he has a lot of credibility here. Not only that they have subsequently helped others because they understood the concept that no book can offer. Whereas you have yet to offer sound advice with evidence of success. First you have to build and establish your credibility - show your work and explain not only what but also how and why. For example, terms like less porous and more porous does not make any sense - more or less compared to what?

If they have already rooted past the planting holes then unless an extra wet period comes or the puddling around them becomes a problem later for other reasons then the only remaining issue is if there were root deformities present at planting that were not corrected. These can result in trees falling over many years later, when the tops get heavy enough to overcome the deficient anchorage provided by there being a portion of the main roots going in the wrong directions (in a circle or forming a J and so on). Also circling roots can eventually become girdling, even pinch off the main trunk. http://drought.wsu.edu/wp-content/uploads/sites/5/2015/06/Horticultural-Techniques-for-successful-plant-establishment.pdf