How Much Water Do Lilacs Need?

Water your lilacs every 10–14 days. Each time you water, soak the ground until it is moist to a depth of 12 inches (30 cm). Very young lilacs can be watered as often as once a week until they are established. Lilacs will not bloom if they are overwatered, so this should be avoided at all costs. They are a plant that does not like “wet feet.” If the ground is too wet, it can damage a lilac’s root system and attract a host of fungal diseases. Unless the ground feels especially dry, do not water your lilacs more than once every 10 days.

How Much Water Do Lilacs Need Per Day?

You should not water your lilacs every day. They are a flower that is very susceptible to root rot and other diseases caused by overly wet soil. Lilacs prefer to get the majority of their water at once with significant amounts of time between waterings. For this reason, you should avoid watering lilacs daily. 

• Lilacs don’t need to be watered daily.
• Give your lilacs 2 inches (5 cm) of water every 10 to 14 days.
• Every time you water your lilacs, provide enough water to moisten the soil down to a depth of 12 inches (30 cm).
• Lilacs need water once the top 3 inches (7.5 cm) of soil are dry to the touch.
• Young lilacs or those that have recently been transplanted can be watered once a week until they are established.

Give your lilac plant 2 inches of water every 10–14 days, depending on the dryness of the soil. Once the top 3 inches (7.5 cm) of soil are dry, they can be watered. If the soil is still moist at this depth, no water is required. If you have just planted or transplanted your lilacs, you can feel free to water them once per week until they are firmly established.

How Do You Water Lilacs?

Lilacs should be watered with a hose or soaker system every 10–14 days. If they are new plants, don’t be afraid to give them some water each week until you can see they have established themselves. You’ll know your lilacs are established once they start putting out new leaves and flower buds. Don’t water lilacs from the top. The flower petals themselves are very susceptible to fungal diseases and powdery mildew.

• Water your lilacs with this soaker hose every 10–14 days.
• Don’t water lilacs from the top—overhead watering may cause mold or fungus to attack your lilacs.
• Lilac flowers are susceptible to moisture-related diseases, such as fungus.
• If there is rainfall or moist conditions, reduce the watering frequency or skip watering altogether.

Lilacs do not need any additional moisture other than what is fed to them by their roots. So make sure you water your lilac bushes only at the base. Try to avoid even splashing water onto the flowers because this can cause mold and fungus spores to spread to the plant. Space waterings at least 10 days apart, but don’t be afraid to go up to 14 days between waterings if natural rainfall has occurred or the ground feels moist at a depth of 3 inches (7.5 cm).

Do Lilacs Like Wet or Dry Soil?

Lilacs prefer moist soil, but not wet or soggy soil. They like their surrounding ground to have some moisture, but it is essential that they are planted in well-drained soil. Otherwise, your lilacs will receive too much water, which will open them up to a whole host of problems, including root rot and fungal diseases.

• Lilacs prefer moist, well-draining soil.
• Semi-dry soil won’t harm established lilacs.
• Consistently dry soil can lead to wilting and drooping.

If the soil does dry out a little bit, it will not harm established plants. However, consistently dry soil can lead to drooping and wilting. In many cases, established lilacs only need watering during drought conditions or periods of extreme heat with a lot of sun. This makes mature lilac bushes one of the easiest flowers to care for.

Can You Overwater Lilacs?

One of the worst things you can do is overwater your lilacs. All lilac varieties can be attacked by mildew, mold, and various types of fungal diseases if their surrounding ground is always saturated.

• Lilacs can be attacked by mold and fungus if they are overwatered.
• Overwatered lilacs might develop root rot.
• Yellow, pale, or wilted leaves are a sign your lilacs have received too much water.
• If your lilacs are overwatered, wait until the soil dries out to a depth of 3–4 inches (7.5–10 cm) before watering again. 

Root rot is a definite threat to overwatered lilacs. Wilted, pale, or yellow leaves are very often a sign of too much water. If any of these occur, or the ground looks consistently moist, reduce watering to once every 14 days until these signs disappear. Remember, if you’re getting consistent rainfall, you may not need to water your lilacs at all.

How Do You Know If Lilacs Need Water?

If your lilacs are drooping or wilting, they need water. Don’t be afraid to break the 10–14 day watering rule if the soil is drying out faster than you thought. The best indicator of whether or not your lilacs need water is to poke your finger into the soil. If the soil is dry at a depth of 3 inches (7.5 cm), your lilacs need water.

• Wilting and drooping can be a sign your lilacs need water.
• Touching the soil is the best way to determine if your lilacs are thirsty.
• Consider spreading a layer of mulch around the base of lilac bushes to help hold in moisture.

Spread a layer of mulch around the base of your lilac bushes to help the soil retain moisture. A 3–4 inch (7.5–10 cm) layer of mulch will prevent the soil from drying out. Mulch will also suppress weeds, plus it gradually breaks down to feed nutrients into the soil.

Do Lilacs Require Lots of Water?

The guidelines for watering lilacs are:

• Established lilacs should be watered every 10–14 days.
• Give your lilacs 2 inches (5 cm) of water during each watering session.
• Each time you water your lilacs, saturate the ground to a depth of 12 inches (30 cm).
• Lilacs do not need additional water until the top 3 inches (7.5 cm) of soil are dry to the touch.
• Young lilac plants can be watered weekly until they’re established.
• Lilacs that are overwatered will fail to bloom.
• Overwatering lilacs can damage their root system and attract fungal diseases.

The common lilac and its more exotic cousins is a drought-resistant plant. It’s best to provide deep waterings infrequently for the best lilac health. Properly watered lilacs will produce an abundance of fragrant flowers from spring until fall.