If the rose is shaded by the tree, it will not perform well. Try cutting it back in spring and moving it to a sunny position. As for the tree, you first need to know what kind of tree it is. Take a picture and ask on the tree forum or take a leaf or small branch to your local extension office for identification. Once you know what it is, you will be better able to diagnose its disease.

yes you need to ID the tree .. mostly to find out.. if you can dig under it.. and grow small plants under it .... there are many trees that are simply ... not cooperative ...

i NEVER treat large mature trees.. first off.. most problems will not flow thru to plants below .. second.. the cost ... third ... it isnt worth it ...

gardening is more an art.. than a science ... i learned by digging holes.. planting things and watching what lived.. and what died ...

i think you are being over whelmed by factoids ... and that is going to worry you into inaction ...

here.. all in one paragraph ....

clean the bed of weeds... cover with 2 or 3 inches of MULCH ... not compost ... buy plants.. pull back mulch.. dig hole.. insert plant .... roots down ... settle soil.. move mulch back.. and water properly all summer.. and 99% of the time you win ...

the previous.. is 4000 thousand hours.. of searching the web.. in one paragraph ...

but do ID the tree and its problem ... there are exceptions to the general rule of ignoring such ...

ken

Flea, your first step will have to be getting the problems accurately identified. The tree images should be posted in the Tree Forum, where both it and the issues it may be struggling with can be identified.

If there are any issues with the rose that can be photographed, it would be helpful in finding common sense solutions for you. Pesticides are not the first thing you should think of, but the last.

No one will recommend a one size fits all without knowing what the problem is, no responsible person, that is. Help us get to the bottom of it and we can help.

We will want to know the general climate in which you live and any immediate cultural factors that might be pertinent.