Do you have to have more than one lilac bush for them to bloom?
No, you can plant just one Lilac bush or tree and enjoy flowers!
Planted a new lilac bush 5 days ago. Originally, noticed some black spots on the leaves so removed those leaves and planted the bush. 5 days later the leaves keep getting black spots. Is this a fungus or insect problem? I don't see any insects on the leaves. Should I return the bush or is it fixable?
This could very well be both issues. A stressed plant for either an infestation or disease can be attacked with multiple issues.
The black spots, that you are spreading and the distortion in the leaves are indicators of a bacterial leaf spot and or insects.
I would absolutely send this plant back for a replacement.
Discard any plant material that has dropped from the tree to avoid contaminating any other plants in your yard.
Here are some links to help you.
http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/management-of-leaf-spot-diseases/
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/common-lilac-problems.htm
They sell lilac bushes at Walmart. The package says 1 root. Is that what I want in order to plant a hedge of lilacs?
This is a bare root Lilac shrub.
Bare roots are an economical way to get shrubs started, especially for growing a hedge.
Plant each Lilac shrub about 5 feet apart for a hedge.
Lilacs need time to grow and settle into their new plantings. It may take 3 to 6 years to see blooms.
Soak the bare roots in a bucket of water prior to planting. Dig the hole plenty wide to so the roots can be spread out.
Water your new plantings well and then every few days for the first month or so. Do not overwater and watch the leaves for signs of wilting in dry weather the first year.
Mulching will help with moisture levels.
Make sure the Lilac's will receive at least 6 hours of sunlight.
Will lilacs grow in Bakersfield, Ca?
You will need to choose a low-chill variety, such as 'Lavender Lady' or 'Alba'.
You can grow it in a partial shade location and you will need to water regularly, Lilac need evenly moist soil, it is not drought resistant.
Success with Lilac in your area is not the best odds, but I understand taking on the challenge!
My lilacs are starting to get leaves but some of them have started with brown leaves instead of green. Is there a problem? Will they be all right? My plants are dwarfs and this is their fourth year with me. Thank you.
You will need to do some further inspection of the plant.
Look for any other leaf issues that may help determine if the leaf damage is Lilac Bacterial Blight.
Has is been dry or excessive rain or wet conditions?
The leaves could be showing signs of either condition.
Here are some links with more information.
http://extension.oregonstate.edu/gardening/how-recognize-treat-and-avoid-lilac-bacterial-blight
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/dwarf-lilac-varieties.htm
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/common-lilac-problems.htm
My lilac tree has many shoots coming up around the bottom of the tree. Should these shoots be cut? Will they disturb the blooming of the tree?
This is a common growing pattern for Lilacs.
Either remove the shoots or propagate them for new plants.
Here is a link with more information.
I am getting 4-5 blooms the first of April in Oregon, which possess very minimal fragrance. Is there anything I can do to enhance that fragrance? What fertilizers would you recommend? I know ammonium sulfate is supposed to enhance blueberry size/flavor. Is there anything like that for lilacs?
Nutrients can't change the fragrance that your Lilac emits, but certainly a healthy plant will produce more flowers and will not only look showy but more flowers will likely produce more fragrance then just a few flowers.
Here is a link with more information on Lilac care.
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-care-growing-and-planting-lilac-bush-plants.htm
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-plant-fertilizer.htm