I have a lilac hedge which is about 5ft high and would like to cut it down to 3 ft. Can I do this and when would be the best time to do this if ok?
Here is a link that will help you.
I live in the Phoenix area and want to know what lilac and butterfly bush will grow here and where to purchase a 'descano' lilac. Thank you
Butterfly Bush or Buddlea should be found easily in your local garden centers or greenhouses.
You can also start plants from seeds for you garden.
https://www.gardeningknowhow.com/ornamental/shrubs/butterfly-bush/butterfly-bush-care.htm
There are some Lilac varieties that are rated for zone 9.
Lavender Lady, Angel White, Excel, California Rose, Ester Staley and Blue Skies.
Check with your local garden centers for these varieties.
You can also do a Goggle search for growers that ship direct.
My lilac bush did not drop its leaves this winter.
Your Lilac to not harden off and abscise the leaves.
If this is a young tree, it will likely be fine. Wait for new growth to began pushing off the old leaves.
Care for the plant normally.
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
We have a lilac tree but can seem to grow anything underneath it. Is there anything you could suggest?
Here are some articles that will help you.
https://www.gardeningknowhow.com/special/shade/ground-covers-for-shade.htm
https://www.gardeningknowhow.com/ornamental/trees/tgen/planting-garden-beneath-trees.htm
https://www.gardeningknowhow.com/ornamental/groundcover/gcgen/ground-covers-under-trees.htm
https://www.gardeningknowhow.com/ornamental/trees/tgen/tips-for-growing-grass-under-a-tree.htm
Can you plant a lilac bush near a vegetable garden? Or will it make everything taste like lilac?
The lilac bush won't transfer its taste to the vegetables, so there's no problem there. However, a lilac planted too close to the vegetable garden will compete with the vegetables for water and nutrients, and the leaves might shade the garden, depending on where exactly it is placed.
A shrub's roots will generally extend out one and a half times the width of the shrub at maturity, so it's best to place it at least that far away.
My older lilacs have no buds. What should I do for them?
As this article explains, older lilacs can have a decline in blooms because lilacs bloom better on younger wood. You may be able to promote more flower bud growth in the future by pruning to promote more growth of new wood:
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-bush-not-blooming.htm
How do I apply phosphorus to my plants? Do I water after I put it down? For lilac bushes around 5' tall how much do you think I should use--no flowers. Same for hydrangeas.Thanks much--Live in Flemington NJ.
The easiest method to add phosphorous to your plants soil is to use Bone Meal.
Adding good organic compost to your soil around the plants will also help.
Follow the directions on the packaging for the Bone Meal product that you choose.
I generally scatter the recommended amount and rake into the top soil. Then water in.
Here are some articles with more information.
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/phosphorus-plant-growth.htm
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-bush-not-blooming.htm
https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/hydrangea-not-blooming.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/bone-meal-fertilizer.htm