I am a beginner Gardener, trying to get the hands dirty for the first time, so pardon my ignorance.
One of my roses was in the shade of a Magnolia tree and had a stunted growth (for a 8 yr old plant) and had not had a single bloom. Well, I transplanted the stunted rose bush into a pot on my back patio with full sun and will water it regularly(it was sprinkler fed in the front yard).
When do I prune it (it is a rounded ball of twigs instead of some V shaped branches), it will have it's first pruning - Now or wait till it is established ? or some now and some later ?
My other adjoining roses in the same front yard bed, have had yellow leaves, black spot disease and are being treated , do I preventively treat this rose too. ? although I do not see any apparent diseases( I dont know how this got lucky, I guess there is God after all)
Please ask any other information, thanks a lot in advance for any and all advice
The best way to start is with a careful pruning using sharp, clean pruning shears, this will activate the growing hormones in your rose bush.
Try to start by clearing the middle of the bush that need to be kept free of growth thus the insect will have nowhere to hide and the air will circulate freely to avoid or diminish fungal infection.
Remove any dead or decayed growth.
Remove crossing branches.
You may want to amend the soil regularly while potted in order to lower the soil pH and make it more acidic. The leaves in your picture look chlorotic. That is when the leaves turn light green but the leaf veins remain dark green; they are unable to absorb iron. You can use liquid iron-chelated compounds sold almost everywhere, garden Sulphur, iron sulfate or green sand.