Questions, Spiders & Mixing

[BURR]

Hope everyone is having a great New Year!

Question 1. Are spiders good?
I have spiders, spiders every where and webs every where. Should I kill them or are they doing good eating the other little bugs. The flowers are outside!

Question 2. Is it OK to mix fertilizer and bug killer and or fungicide in the same water bottle?

And if I can't mix then should I spray each on a different day?

In the pass I just put a little of everything in a one liter sprayer and started spaying.
The local guy said NO, don't do that.

So maybe you'll can give me a little input. I ain't to smart but I have a few smart books to help me but they don't cover this (I think).