I planted about 5 years ago and it is still the same size as when I planted it - what can I do?
I am listing a few links for you to refresh you on the growing conditions a Lilac needs.
Check soil conditions sunlight and watering to start. A soil test would be a good idea.
This will help you determine if you need to make any corrections.
Your local county extension office can help you with a soil test.
https://www.gardeningknowhow.com/extension-search/
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-care-growing-and-planting-lilac-bush-plants.htm
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-bush-not-blooming.htm
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-plant-fertilizer.htm
I have bought some lilacs that are around 2 feet tall. They are still in the pot in which I bought them last week. Is it advised to wait until fall to plant these or is it safe to plant them in the middle of July? I live in Manitoba, Canada. Thanks.
Though it is ideal to plant new shrubs in the spring or fall, it may be easier to plant them now then keep them healthy and watered in pots.
Daily water for the first 2 weeks is important. If the temperatures are above 85 degrees, twice a day is necessary.
Here is a few links to help you.
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-care-growing-and-planting-lilac-bush-plants.htm
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/damage-from-lilac-roots.htm
When is the best time to trim lilacs and how much can be trimmed off?
I would not prune it back by more than 1/3 in any one year. Cutting it back further than that could harm the plant. This article should help with that: https://www.gardeningknowhow.com/ornamental/shrubs/lilac/pruning-lilac-bushes-when-to-trim-lilac-bushes.htm
Can you cut down overgrown lilac bushes and have them come back to form flowering neat bushes in the spring?
Here is a link to an extension article that will give you a few options on how to rejuvenate your overgrown lilacs. Regardless of your approach, it will probably take a few years to get vigorous attractive shrubs.
http://lancaster.unl.edu/hort/articles/2005/prunelilacs.shtml
For more information on pruning lilacs, visit:
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/pruning-lilac-bushes-when-to-trim-lilac-bushes.htm
I would suggest you cut them down to no lower than a height of four feet. However, be sure there are new canes coming up as lilacs rejuvenate themselves through new canes. If there is a sufficient number of new canes coming up, cut and remove maybe three of the old canes that appear to be dying.
You can dig out new canes around the outer perimeter and start new bushes with these new canes. The new canes also can be planted to bolster aging lilacs that are the same variety.
Our neighbor has a large lilac bush, and my wife noticed inside on the bottom of the bush was a nest. We are unsure if the nest is from a tent caterpillar or a gypsy moth. Do either, or both, of these pests attack lilac bushes? If so, what should our neighbor do to salvage the bush?
Yes, these pests can occasionally affect lilacs. Here is more information that may help:
https://www.gardeningknowhow.com/problems/pests/tent-worms-tent-caterpillar-home-remedy.htm
https://www.gardeningknowhow.com/plant-problems/pests/prevent-caterpillars.htm
Is it too late to prune lilac bushes now?
The best rule of thumb on pruning lilacs is to do it right after the flowers die off in the summer. Here is an article that you may find helpful: https://www.gardeningknowhow.com/ornamental/shrubs/lilac/pruning-lilac-bushes-when-to-trim-lilac-bushes.htm
Three years ago, I moved back into a house I'd lived in as a child. The house was a rental for 27 years and the landscaping was indifferently maintained. Three lilac bushes that my mother planted in 1977 remain, but weed trees have grown in amongst the roots of two of them. I have twice cut the trees as close to the ground as possible, but I'm also active duty military and have been deployed over the last two growing seasons and the buggers keep growing back taller than the lilacs while I'm away. What can I do to kill these things without killing the lilacs as well?
Here is an article that you may find helpful: https://www.gardeningknowhow.com/ornamental/trees/tgen/weed-trees.htm