Q.Is This A Rootstock Sucker On My Lemon Tree?
Hello! I’m new to fruit trees and needed some tips and advice on taking care of my Lisbon Lemon Tree. I was wondering if this was a root sucker? Should I prune it? Also, some leaves on top are light green and have white dots what should I do? How should I help my lemon tree become healthier?

Certified GKH Gardening Expert
Yes, that trifoliate branch is part of the rootstock. You'll want to remove that. The white dots are likely indicative of a spider mite or aphid infestation. Sucking insects tend to cause these issues. It is sapping nutrients from the tree, as you can tell from the discoloration. Azadirachtin, and Pyrethrins. Both are plant derived, and my go-to.
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/azadirachtin-vs-neem-oil.htm
https://www.gardeningknowhow.com/ornamental/flowers/chrysanthemum/chrysanthemum-pest-control.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/pyrethrum-in-gardens.htm
https://www.gardeningknowhow.com/plant-problems/pests/insects/homemade-aphid-control.htm
https://www.gardeningknowhow.com/plant-problems/pests/insects/spider-mite-treatment.htm