Lilacs

Lilacs are very hardy shrubs that are able to withstand winter temperatures of -60 degrees F. Unfortunately, lilacs cannot do well in the South where the winters are too mild to provide the necessary seasonal rest period required.

Lilacs can grow from 3 feet to 10 feet tall, and in some cases can reach a towering height of around 30 feet (most lilacs average under 10 feet in height). Lilacs are very long lived and require very little effort to keep them going year after year. Some varieties can live well over a 100 years which makes them great for long-term landscaping plans.

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Common Lilac: This is the best known lilac and can grow up to 20 feet in height. The leaves are somewhat heart shaped and very fragrant and are usually the famous lilac color.

Hungarian Lilac: This lilac has dark rose-lilac colored leaves and grows to a height of about 10 feet.

Persian Lilac: This lilac can grow to 10 feet and has very fragrant pale lilac colored flowers. This is a good shrub for hedges.

Chinese / Rouen Lilac: This lilac is a cross between the Persian and Common Lilac. It can grow to more than 10 feet in height and had a fragrant lilac-purple colored flower.

Late / Himalayan Lilac: This lilac is known as “Late” because it blooms later in the season and is a great compliment to earlier blooming lilacs. It grows to about 10 feet and produces clusters of rose-lilac colored flowers.

Large Leaf Lilac: Opposite of Late / Himalayan Lilacs, this lilacs bloom is among the first to bloom in spring. They grow to a height of 12 feet and have large red tinted leaves that turn very red in the fall.

Little Leaf Lilac: This is one of the shorter lilacs at 5 feet in height. It is a late blooming lilac and produces very fragrant and small flowers.

Dwarf Korean Lilac: As the name implies, this lilac grows to only about 4 feet in height. Little does not mean a lack of very fragrant blooms however.

Tree Lilacs: These are called tree lilacs because they grow to heights of 30 feet and resemble a tree. These lilacs produce clusters of off-white blooms. Another Lilac Tree variety (Japanese Tree Lilac) produces clusters of yellow-white flowers.

Many Other Lilacs: This preceding list is only partial but covers some of the more well known types of lilacs. If you are in a part of the country that can grow lilacs, you can try different varieties and have blooms all season long with an array of flower colors.

In addition to lilacs, there are hundreds of other flowering shrubs in all sizes, varieties, and color of flowers. To choose flowering shrubs think about space requirements, height, color of flowers, and the hardiness temperature zones they can thrive in.

Tips for Planting Lilacs:

How to Plant Lilacs:

Start with digging a hole that is big enough to accommodate the roots. By not cramming the roots into the hole you’ll leave them room to develop a good root system. You’ll need to include good soil and compost when doing this to produce the very best results.

When to Plant Lilacs:

The ideal time to plant lilacs is in the fall after their leaves have dropped off. Do this before the ground freezes or you end up with all kinds of problems. You can also plant lilacs in the spring before their buds start to unfold but this is harder to time correctly. Over wintering gives the lilacs root system a head start in the spring when they begin to grow again.

Where to Plant Lilacs:

Lilacs need plenty of space and do best when out in the open getting direct sunlight. They thrive in sun and also in soil that has good drainage. Lilacs will do well in all types of soils but prefer neutral or slightly alkaline soils. To get better results you can mix in fertilizers that are low in nitrogen and high in phosphate and potash.

Pruning Lilacs and other Flowering Shrubs

Pruning Stimulates Growth… The main reason to prune flowering shrubs is to maintain a larger portion of the young and vigorous growth wood. Most flower buds are formed on the current or previous year’s growth. This makes it important to remove the 1/3 of the oldest wood annually to help keep your flowering shrubs vigorous and producing blooms.

• Helps control the size of your flowering shrub
• Influences the success of flower buds
• Rejuvenates older and overgrown shrubs
• Maintains the overall appearance
• Maintains the overall health
• Encourages growth below the pruning cut

There are several considerations to look at when pruning a flowering shrub including health and overall condition, the season a particular flowering shrub blooms, and what you are trying to accomplish in terms of height or shaping.

Lilacs are springtime Flowering Shrubs:

Pruning spring flowering shrubs is different than summer flowering ones. Spring flowering shrubs produce flower buds off of wood produced the previous season. As a result, you will prune these shrubs after they have flowered in the spring and before the next yea’s flower buds are set.

By pruning at the wrong time (winter or early spring) you remove many of the flower buds before they ever have a chance to bloom. In addition to lilacs here are a few examples of other spring flowering shrubs:

• Honey Suckle
• Forsythia
• Viburnums
• Chokeberry
• many Others…

* You want to prune problem flowering shrubs because dead or injured branches attract insects, rotting and disease. They key here is to remove problem branches as soon as they are noticed.

* You’ll want to cut out damaged, dead, or diseased branches.

* Cut all the way back into the healthy wood or below the problem branches.

* Cut back about 1/3 of the overgrown stems (or branches that cross rub) to their base.

* Remove all withered flower clusters to the nearest bud (unless fruit is expected & wanted).

Notes on What to Avoid when pruning Lilacs & Flowering Shrubs:

* When pruning try to maintain the shrubs natural shape versus ragged edges.

* Do not cut too much off the flowering shrub at any given time or you’ll endanger the health and appearance of your plant.

* Stagger the cuts so your flowering shrubs shots are at various heights and look more natural.

* If you remove new shoots at the base of your flowering shrubs you’ll limit the size of your shrub.

Specific Types of Pruning for Lilacs: Shearing

Flowering shrubs were not meant for this technique. Usually shearing is done for formal hedges used for property lines or out in front of your home. Use hedging shears to remove newer growth shoots and leave about 1 inch of the previous growth to allow the stems to re-grow.

Pinching

Pinching is the removal of shoot tips allowing for additional side branching thus increasing the plants bushiness. This is usually done on smaller shrubs in springtime.

Deadheading

Deadheading is basically removing flowers that have run their cycle. This is done by hand and can encourage a second flush of flowers for some types of flowering shrubs.

Thinning

Thinning is the easiest and most common way to refresh your shrubs. It preserves the overall shape and is done by removing interior branches with a pruning saw or loppers. You will cut selected branches all the way back to the point of origin and only thin about 1/3 of the larger branches at any given time.

Heading Back This technique is used to reduce the overall height of your shrubs.

Rejuvenation

Rejuvenation removes new shoots that are leggy, overgrown or for plants that sucker readily from the shrubs base. This entails cutting back when the shrubs are dormant.

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Shade – The location is too shady for good bloom production.

Competition – There may be too many other competing plants affecting root growth and nutrition.

Pruning – If you prune at the wrong time of the year for the type of flowering shrub.

Fertilizer Ratio – The ratios could be off on your fertilizer mix. For example: Too much nitrogen produces excess vegetative growth versus flowers. Also, too little phosphorus may cause a lack of flower blooms.

Shrub Suckers - Too many suckers at the base of your flowering shrub will limit the blooms.

New Plant – It’s a new shrub and simply has not had the chance to settle in and recover from transplant shock.

Water – Your flowering shrub has not received enough water.

How to Start Cuttings for Lilacs & Flowering Shrubs:

Cuttings are a good idea if you love a particular lilac bush or flowering shrub and want to start another in your yard or give it to someone. This is usually easy to do but Rhododendrons, Azaleas, and Camellias are a little harder to start. To get a cutting going do the following:

Planter Preparation for Lilacs & other Flowering Shrubs:

* Get a pot with plenty of drainage holes.

* Clean the pot out very well with soap and hot water.

* Fill the pot with a mix of sphagnum and perlite (equal parts) and moisten the mix.

* Make holes for the cuttings by poking a pencil into your mix.

Cutting Preparation for Lilacs & other Flowering Shrubs:

* Remove a new tip from the end of a branch.

* Remove flower buds and keep 4-6 leaves.

* Make a 5-6 inch cutting from that tip with a sharp knife.

* Make a small fresh cut at the bottom of the stem.

* Moisten the bottom cut on your stem and dip in a rotting hormone.

Planting the Lilac or other Flowering Shrub Cutting:

* Place the cuttings in the pencil holes in your pot.

* Put small stakes around the cutting to keep it stable.

* Cover them with a plastic bag.

* Put under fluorescent lights for 16 hours if possible or under direct sunlight.

* With the plastic bag in place watering will be minimal.

NOTE: Be patient, rooting for lilacs or other flowering shrubs can take 6-8 weeks or longer. Make sure you harden off your lilacs before planting them outside.