first thing you need to do.. is start learning the latin names.. so we can actually talk about the plants you actually have ... for example ... here in MI.. i used to dig my very large dahlia.. and store the roots .. like sweat potatoes.. in compost on the basement floor ... the are NOT annuals ... they are perennials .. in the jungles/rain forests they most likely come from ... when you start with the latin.. then you can find out if you actually have an annual ... which is NOT worth messing with PERIOD ... or you are actually dealing with a perennial.. that we in the great white north.. usually use as a annual ... now.. flowering is usually triggered by the inclination or declination of the sun.. along with many other variables .... that is why some do not bloom until fall ... i took me many readings of your post.. to understand what you were asking.. and i do NOT believe that you can change the genetic predisposition of a plant.. and force it into longer life .. by not allowing it to flower ... you will not convert a true annual.. to a perennial.. by not allowing it to sexually mature ... at some point or another.. as the sun declines in fall.. the plant will start to fail ... if it is a true annual ... you will not overcome that ... so.. to fully discuss this topic.. we need to know exactly what plants we are talking about.. since there seem to be both perennial and annual versions of the plants you list ... now ... impatiens.. root in days in water .... take a piece or two.. root them.. and then pot them and put them on a window sill.. and they will look good for about 2 months.. at which point.. you root a couple more pieces.. and once potted .. throw out the old.. and do this all winter.. until frost is gone.. do NOT try to get the first ones to live.. they will look horrible ... but you are not going to throw them in the root cellar ... it simply will not work with these plants ... so your option is propagation ... [i know you can throwgeranium in the root cellar .. but i think of those as woody plants.. which allow for some drying and survival.. impatiens.. on the other hand are 99% water.. and they will rot in the dark IHMO] ... finally.. there is not going to be one hard and fast rule for them all ..... again .. back to the latin.. and looking into propagation methods and storage methods of various plants ... any clearer??? ken

Might be better to sink the pot to just over the rim. Some of the tomato roots will grow out the drainage holes. That might be enough to sustain it. Make sure surrounding soil has reasonable moisture & nutrients. Basil would not really tolerate a buried stem.

I am not a botanist, but from what I understand here are some possible scenarios why some plants act as annuals vs. perennials. - Some plants are perennial in warmer zones, say zones 7-11, but will behave as an annual in colder zones. For example, Verbena bonariensis is perennial in warmer zones, and annual in my zone, but some plants have survived over the winter in my garden when we have a mild winter, it's in a sheltered location, or had lots of snow cover over the winter to protect the roots of the plant. Snapdragons also do this. - Some plants are perennial in suitable garden conditions, but die over the winter in others - especially those that require gritty well-drained soil. They will basically rot and die over the winter because the soil is too soggy for them. - Some species of plants have different "varieties" which are naturally occuring variations of the plant in different regions of its native range. Sometimes, a variety in one region will be more perennial than one in another region. Rudbeckia hirta (Black Eyed Susan) is especially confusing, because it can act as an annual, biennial, or short-lived perennial (more than 2 years). It has many cultivars ("cultivated variety") including 'Cherry Brandy', 'Indian Summer', 'Irish Eyes', 'Autumn colors', 'Cappucino', 'Toto', 'Gloriosa', etc. I WS'd a bunch of these last year, most of which bloomed the first year as an annual, and have one 'Indian Summer' that has bloomed for 2 years now. I'm dying of curiosity to see what comes back this year.

Thanks Yaslan, I don't blame you one bit for not wanting to "hack" off your mango tree. Every time I do it...I still have panic attacks,lol...its not for everyone. Actually, I don't ever recommend it to any one in fear that it won't turn out well for them. I only post it here, so everyone can see that you can do it and responds well if you want to keep your trees "dwarf". No one will ever blame you for not wanting to do it. A hand truck or dolly is def. very helpful! Good luck with your new trees. About your P. Guava, I know you live in WA. You might want to check the min. temps that PG can take...but if memory serves they can take it down to 15° with very little damage. I've heard that they take colder, but do suffer some branch and twigs dieback? But I've heard that they do come back. Remember I'm in FL, although this year I did have a few nights of low to mid 20's...that is NOT our normal winter by any means. Normally we only have to deal with the occasional freeze.I would check with your local area to make sure your Pineapple Guava will survive your normal winters...just to be sure.