Kayan, It's impossible to give you input about removing or even pruning the trees without seeing them. Unless someone has seen the site, they don't have the needed information. Pictures might help some, but even then you're only going to get guesses. If you don't have a feel for how much effort it will take, I'd recommend that you get a certified arborist to take a look. If you need the trees removed and don't have the required experience to do it, I'm not sure what other choice you have but to pay someone to do the job. You should be able to get free or low-cost estimates before contracting with someone to do the job. I'd get at least two or three estimates and check to be sure the company is properly bonded and insured before making a decision. The decision of whether to take the tree's down, prune them, or leave them as-is will have to be yours. You'll have to consider things like safety, aesthetics, and the financial aspects in your decision, but the right answer is the one you decide on. No one else is really in a position to make that decision for you unless public safety or local regulations about tree care/maintenance are involved. Also, I don't see how the decision to remove or leave the trees is going to have any real impact on your "garden's air". The trees aren't likely to block fumes. At best, they may help to block the site of the smoke coming from the trucks. Recommendations for replacement trees might be possible if we knew how much room (width and height) you had. Pictures, any specific information you can give about the site, and more information about the type of trees you'd like would also help. Below is a link to a site that has lots of good information about tree maintenance/removal and tree care in general. Here is a link that might be useful: International Society of Arboriculture's Website

I just got a big and beautiful tree at Boething Tree Nursery in Woodland Hills. 818-883-1222. We had searched everywhere, even as far south as San Juan Capistrano, to find a specific specimen tree (14 ft tall). Someone here on Garden Web recommended them and they were great! Good prices and a huge selection. Good luck! Brooke

Here is one link : http://edis.ifas.ufl.edu/CG009 Foot rot results from infection of the scion near the ground level, producing bark lesions which extend down to the budunion on resistant rootstocks. Crown rot results from infection of the bark below the soil line when susceptible rootstocks are used. Root rot occurs when the cortex of fibrous roots is infected, turns soft and appears water-soaked. Fibrous roots slough their cortex leaving only white thread-like stele. Foot rot and root rot can be caused by P. nicotianae or P. palmivora. When managing Phytophthora-induced diseases, consider integration of cultural practices (e.g., disease exclusion through use of Phytophthora-free planting stock, resistant rootstocks, proper irrigation practices) and chemical control methods. Phytophthora management with chemical control should not be considered until other potential causes of decline in tree production are evaluated and corrected. Sounds like a tough disease to control or cure !

Debbra, first off, if you can post photos, it really does help us to better help you. Without photos, I would say to first, clear our the ice plant. As Greg has mentioned, it is competing for water and nutrients with your poor citrus tree. Next, make sure the watering situation is fixed. Your trees should be on a drip or micro-drip system. Again, as Greg mentioned, do not allow your sprinklers to hit the trunks of any of your citrus trees. It encourages rot. Next, make sure you've got a nice well formed around your citrus trees at or somewhat beyond the tree canopy. That's where your feeder roots reside for your trees. That way, the water can collect and seep down to the feeder roots. Mulch your wells, keeping the mulch away from the trunk (again, to prevent moisture from collecting and causing rot). Next, fertilize your poor tree with a good quality citrus fertilizer. Fertilize again in 4 weeks, and then put down a 3rd application in another 4 weeks. Water the fertilizer in well, and never apply fertilizer to a dry tree. Remove all the fruit, let the tree put it's energies into re-developing a canopy. Don't prune anything until you see leave flush, and can clearly determine dead from living branches. Then, prune away all the dead branches, making sure not to leave stubs of branches, nor prune so closely that you prune into the branch collar (the flare right where the branch connects into the trunk). Citrus trees require little pruning. Just removing dead wood mainly from the interior of a mature tree, or some very minor pruning for shape. Remember, citrus are tip fruiting trees, so if you over-prune, you're not going to end up with any fruit :-) And, I don't recommend going over to the Orchards Forum, you're much better off on the Citrus Forum for citrus questions (you'll get sent here if you post there about citrus.) And, you can see how I have my zones for California. USDA zones are basically worthless here in California due to all our micro-climates. I differentiate between the two, since there are certainly other folks on the Citrus forum who reside in other states, so that helps them to better understand my climate in general. But, there must be 10 Sunset zones within the USDA zone 10 here in California! Patty S.