Leaves have holes like a disease is eating away at it. What is it?
It would be hard to say without a photo. It could be fungal, or insect related, most likely. If you can include a photo, I will be more than happy to help.
Certain bushes such as my butterfly bush have leaves that are stuck together and seem to have a sticky residue? What is doing this?
There are actually quite a few insects that do this. Unless you catch the pest, it can be hard to say, exactly, what is eating your plants. You can use broad spectrum insecticides that you can make yourself at home until you can see the pest.
This collection of articles will help: https://www.gardeningknowhow.com/special/organic
I have a Buzz Magenta Buddleia , in a large pot. I used some compost and lots of agri grit when planting up , but the leaves are turning yellow. this years growth seems ok atm but last years leaves ( smaller and nearer the base) are really bad and falling off. Any ideas? Can i take it out of the pot to see if it's water logged without damaging the new growth ( nearly ready to flower)?
Compost alone may not be a good growing medium. A good potting soil can be amended with some compost. Yes, you can try repotting to correct the soil.
Watering issues; too much or too little can also cause yellowing leaves.
The link below will help you access the care.
https://www.gardeningknowhow.com/ornamental/shrubs/butterfly-bush/butterfly-bush-container-care.htm
It is planted in sandy soil next to a Davidii Buddleia which is absolutely fine and doesn't get eaten
If you can include a photo, it would help me to identify the issue. It sounds like, though, that the cultivar next to it has a disease resistance unlike the one beside it. It sounds like shothole fungus.
This article will help: https://www.gardeningknowhow.com/plant-problems/disease/shot-hole-disease-fungus.htm
When my butterfly bush gets extremely tall the branches are so heavy they fall over to the ground when should I trim to not make this happen? I don't want them to look awful after trimming...
Pruning will help keep your plant from becoming to tall and heavy.
These articles will help you.
https://www.gardeningknowhow.com/ornamental/shrubs/butterfly-bush/butterfly-bush-pruning-how-to-prune-a-butterfly-bush.htm
https://www.gardeningknowhow.com/ornamental/shrubs/butterfly-bush/butterfly-bush-care.htm
Hi, I have a Butterfly bush which was planted last spring. Thank g-d it returned this season. However, The leaves have started to Yellow at the bottom working their way up. Towards the top the leaves are speckled yellow. The plants have been fertilized and properly watered. Please help, Thanks! Sam
This appears to be a magnesium deficiency. This is very common in acidic soils, but can be a sign of actual deficiency as well. Dolomitic lime will usually correct this, and bring it to a stable and close to neutral pH.
This article will give you more information on the care of these: https://www.gardeningknowhow.com/ornamental/shrubs/butterfly-bush/butterfly-bush-care.htm
Got a bargain buddlia, but it is tall and no lowerleaves, can I cut it down
When a shrub is struggling to get established in mid-summer weather, it isn't a good time to prune. Butterfly bush often loses some of its lower leaves as they get shaded out. Pruning signals "time to grow more branches". Right now, the most important task is to get those roots settled. It can be cut back to 8 inches or so in late fall, after leaf drop when it is dormant.