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How Deep Are Lilac Roots? (Lilac Root System Explained)

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While growing any plant in the garden or nearby the house, it’s essential to know how deep the root system of that plant for in the ground so that you can be assured that the roots won’t damage your home’s foundation.

And the same concern goes for while growing lilacs too, thus, wanting to know how deep lilac’s roots are might be one of your common queries. So, let’s quickly find out the answer. 

How Deep Are Lilac Roots?

The root system of lilacs is not deep, rather it is a shallow root system, therefore, the roots of lilacs tend to remain at top of the soil surface and go as deep as 18”-24” in the soil. However, due to the natural tendency of lilacs to settle in an area, the roots might spread out a little bit.

You will find quite a lot of lilac varieties out there such as Korean lilac, Japanese tree lilac, Miss Kim lilac, Texas lilac tree, common lilac, lilac bushes, and so on.

Thus, while thinking of growing any of these lilac varieties, wanting to know how deep each of their roots goes in the soil is natural. Therefore, take a look at the individual explanations added below regarding these lilac types. 

Lilac Bush Roots:

In general, the roots of a lilac bush will go deep only about 18”-24” deep in the soil, it’s naturally supposed to stay concentrated on top of the soil.

And the reason behind it is that lilac bushes have a shallow root system that doesn’t go deeper into the ground. However, the roots may spread over time a little bit and it’s considered natural. 

Common Lilac Roots:

Common lilacs are one of the lilac bush varieties and it falls in the category of the large and upright lilac bushes.

Hence, the common lilacs are lilac bushes as well, therefore, the root system of common lilacs is shallow too. This means the common lilac roots are deep as 18-24” in the soil. 

Japanese Tree Lilac Roots:

Lilac trees are said to have deep roots, however, whether it’s a lilac bush or lilac tree, most of the time even the roots of a lilac tree are seen to go as deep as 18-24” in the topsoil.

Thereby, it can be said that the Japanese lilac tree roots will be stay concentrated at a depth of 18-24” in the soil. 

Miss Kim Lilac Roots:

Miss Kim lilacs are lilac shrubs, and it’s stated that lilac bush and shrub roots regardless of the variety are deep as much as 18-24” only which remains concentrated on the topsoil surface.

However, the roots of Miss Kim lilac will spread quite much in diameter. 

Korean Lilac Roots:

Korean lilacs are actually called dwarf Korean lilac, and as the name implies, these dwarf Korean lilacs grow up to only 5-6’ upon maturing. As a result, their root system is shallow as well and is about 18-24” deep. 

Texas Lilac Tree Roots:

Texas lilacs aka Chaste lilac tress are shrub plants which means like other shrub varieties of lilacs, their roots don’t go deep as well in the ground and stay only up to 18-24” on the topsoil surface. 

Are Lilac Roots Deep Or Shallow?

The root system of lilac bushes and shrubs is shallow. As a result, if you have a shallow foundation and have planted lilacs around your home or in the yard in front, the roots of a lilac bush or shrub will go down to the base of the shallow foundation only, nothing more. 

But if there’s a deep foundation, don’t worry at all. The shallow root system of lilac won’t reach that deep, so there aren’t much chances of any damage. 

However, some sources stated that the lilac tree root system is deep and extensive, and the roots can go down up to a meter or more in the soil. Check the depth of lilac shrubs, bushes, and trees’ roots before planting. 

Do Lilac Trees Have Invasive Roots?

Lilac trees don’t have invasive roots, which means the roots of lilacs aren’t likely to grow in the ground to find nutrients and water while making pathways under driveways, water lines, building foundations, walkways, and sewer pipes, etc. 

However, lilac roots are not acknowledged as invasive roots only when enough room has been left between the lilac tree/shrub/bush and the building’s foundation/driveway/water lines, etc. Otherwise, lilac roots sometimes can be invasive. 

So leave at least 12 feet of space between the lilac shrub/tree/bush and the structure to prevent any invasion of lilac roots. 

How Much Room Do Lilac Roots Need?

If you are planning a lilac seedling in the ground then the roots of the seedlings will be needing at least 2 inches to 3 inches more space in the ground than where they grew up originally. 

Also, remember that even if lilac bushes/trees/shrubs’ roots aren’t assumed as the invasive root system, the roots sometimes can be invasive.

So to avoid such an unpleasant situation, you must plant a lilac at least 12 feet (4 meters) away from your home’s foundation/driveway/pipe lines/sewage line, etc.

This suggested space between a lilac bush/tree and a structure is sufficient to prevent the risk of structural damage. 

What Kind Of Root System Does A Lilac Bush Have? 

The root system of lilac bushes is a shallow root system, which means the roots of lilac bushes don’t go too deep into the ground, rather the roots remain concentrated only up to the topsoil surface.

Therefore, you will notice a lilac bush’s roots reach deep into the ground up to 18-24” only. 

Also, lilac bushes are most likely to have an invasive root system as well, as a result, there are almost zero chances that any structure such as a house’s foundation, driveway, sewage line, or anything would be damaged by a lilac bush’s roots.

But in this case, you must plant the lilac bush at 12 feet distance from the structure to avoid damage. 

Is It Difficult To Dig Up A Lilac Tree? 

The difficulty level of dogging up a lilac tree depends on the size of the tree and the soil.

If you are trying to dig up a large and matured lilac tree then it can be really difficult that you might need extra people to help you in digging and a vehicle to pull the tree out of the ground. 

But if it’s not a big and matured lilac tree then you can expect to dig down around the lilac tree alone and putting less effort.

Also, if the lilac tree is planted in clay-like or hardpacked soil then it surely would be difficult to dig up a lilac tree. 

How Do I Dig Up A Lilac Bush? 

Well, digging up a lilac bush might seem a little difficult if you are going to dig up a lilac bush for the first time. Therefore, to make the process easy for you, a step-by-step guide is added below.

Water The Ground: 

Before you dig the lilac bush, you have to water the nearby ground around the lilac bush thoroughly so that water helps the soil in the ground to loosen up completely.

It’s easier to dig deep in a loosened up soil, rather than a hard soil because you will be able to dig and pull the lilac bush will less effort from the ground. 

Dig Down From All Sides: 

Next, you will be needing a shovel and a hoe, use that shovel and the hoe for digging down the lilac bush from all the sides and keep removing as much dirt and soil as possible from the hole you created by digging down.

And you must keep digging down until you have reached the foot of the rootball, then gradually free as much rootball as possible.

Pull Out The Rootball: 

Now at the very last step, again use the shovel and slowly pull out the whole rootball from the ground, and while doing so use pruning shears for cutting the extended roots that have crossed the anticipated rootball diameter. And brush dirt from the bare roots using your hands.

If the lilac bush is a young one, after digging down from all sides, you can pull the bush out by hand. 

However, if the lilac bush is a strong and old one, you better use a tractor for pulling out the lilac bush.

After digging down from all sides, tie a rope around the lilac bush’s base and keep adding tension to it through the tractor until the rootball is completely pulled out.

Final Thoughts 

Whether be it a lilac shrub or bush, the root system of lilac is shallow, thus, the roots of lilacs don’t go too deep down in the ground. So, regardless of the lilac variety, the root system of lilacs is 18-24” deep into the soil. But the roots can spread much in diameter to settle down the tree.

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