Hi Violetta and welcome! There's definitely no "stupid questions" . As they say - the only stupid question is the one not asked!! LOL To try to answer some from my experience: 1.) Mulch is usually used as a soil cover to do a number of things including to help the soil retain moisture, and in cases of organic mulch, to eventually break down and add to the soil. Some mulches like gravel can often add minerals to the soil. For containers, I have found that it helps tf the clematis. Some will even plant a ground-cover type plant around a clematis base to do the same. Basically, the clematis likes moist roots (but not soggy as that may rot it out) when it is in the sun. 2.) o keep the soil surface from drying out so fast. And yes, it will help "shade" the roots of the clematis. Some will even plant a ground-cover type plant around a clematis base to do the same. Basically, the clematis likes moist roots (but not soggy as that may rot it out) when it is in the sun and they definitely prefer sun to get alot of bloom. 2.) Regarding containers appearance - I expect it is more "in the eye of the beholder". I don't consider my plain plastic containers as "ugly" (unless they are really stained or scratched up or split). The containers are just that - containers that hopefully have a beautiful plant in them. There are many who really like beautiful terracotta or ceramic containers but for me - these are often heavy and can crack after awhile due to expansion and contraction during winter weather. So as you surmise, a plastic pot with the plant can be placed inside the decorative pot to get the best of both worlds. 3.) With respect to petunias and bloom - sometimes they will pf the clematis. Some will even plant a ground-cover type plant around a clematis base to do the same. Basically, the clematis likes moist roots (but not soggy as that may rot it out) when it is in the sun. 2.) ause while going through a vegetative cycle before blooming again. You could consider pinching off the growing tips to encourage side-branches that will eventually give you double the blooms. Giving them a high-phosphorous fertilizer boost may also help. 4.) There is nothing stopping you from growing a cherry tree - just make sure that you put it in as large a container as you can drag out there 20" or greater and look for one that is on dwarf stock (then you can summer prune to keep it smaller). There are some vines like moonflower (Ipomoea alba) that would love your S-SW exposure and would cover your window in no time (plus would give you large white blooms in the evenings). The moonflower vine's cousins - morning glories - are also another that you could try. Some climbing roses (in a large container) could be positioned against the window and would also handle that exposure and can diffuse the sun coming through the window. Honeysuckles are a nice viney/shrub that could fit the bill too. Additionally, once your little clematis has grown up, that could be trained to grow on a trellis in front of the window as could vines like passifloras, which are fast growers. Your container plantings are really pretty, so don't bemoan them!!! It has taken many of us years to get where we can't even barely walk out on our balconies anymore (LOL) so don't be afraid to take your time and get hooked on container gardening!

I have had good luck with salvia (all kinds) and vinca major in my hot-sun window boxes. Portulaca works well, too.

Inhot climates pansies do well with part shade. My sister has window boxes on a south facing window. She solved the drying problem but using drip irrigators across the top. The hoses to them go right up the house and across the boxes. T

People use the term "direct sun" in different ways. Sometimes it means "without anything but air between the sun and the object", and that must be what you mean. In other cases it is used as the opposite to reflected or filtered light (light has passed through cloth or frosted glass). The latter reduces the strain on the plants as the light is distributed over a larger area (from the plant's point of view). In this sense, direct light may or may not have passed through a sheet of glass/plastic first, which reduces the ultraviolet (UV) radiation considerably. So, one must always find out what a particular author means with the term. Plants can get burnt behind glass due to overheating, but it has not been a problem for me. I use a small fan to circulate the air on the windowsill. UV light is not a problem there, the windows are triple-glazed ... Outside is much worse. The temperature is lower and ventilation much better, but still the plants often get scorched. I blame the UV light for this, the problem gets worse on days with high UV index. I keep plants that are extra sensitive to UV indoors, and they have never been damaged there. It depends on where you live too (sun intensity), of course. I don't know how hot it is behind your windows ...