Lilac plants don’t require a lot of food or fertiliser. A 10-10-10 fertiliser mixture applied yearly in the early spring is what we advise. (The amounts of nitrogen, phosphorus, and potassium, or NPK as they are popularly known, are represented by the digits 10-10-10 in the formula.) Early spring fertilisation of lilacs with a high phosphorus solution encourages blossoming.
Coffee grounds and grass clippings are also excellent sources of nitrogen. Use in moderation since an excess of nitrogen in the soil can lead to subpar blooms. The ideal soil conditions for lilacs are slightly alkaline (6.5–7.0 pH), wet, and well-drained. The soil may become more alkaline by adding bone meal to it. Use Miracle-Gro Shake ‘n Feed Flowering Trees & Shrubs Plant Food in the spring if you decide to feed your plant. Last but not least, lilac plants dislike acidic soil. Epsom salts can be used to encourage blossoming while the plant is dormant.
A lilac bush needs fertiliser, right?
Lilac bushes respond well to fertiliser made from bone meal. This is as a result of increased soil alkalinity. It is a simple natural plant food that the lilac may consume.
Lilac fertilisation isn’t necessarily required until the first and second years after planting. To sweeten the soil and prevent too much acidity, they could be fertilised with superphosphate and limestone when they are planted.
You can exclude standard fertiliser mixtures if the soil has the right balance and has a lot of organic matter. The only bushes that will truly benefit from annual feeding are those planted in poor soil. When you do feed the plants, use a 5-10-10 ratio. Around the plant’s root zone, distribute 1 cup (237 ml) of granular food evenly, and then water the soil.
Can lilac bushes be grown using Miracle Grow?
3. Take the plant out of its pot and place it in the hole. Make sure the top of the root ball is about an inch or more above the soil surface.
4. Apply the soil mixture all the way around the root ball, pressing it down firmly.
5. Take a long drink.
6. Mulch the area you just planted to a depth of 2 inches, being careful not to pile mulch up against the base of the plant. This will help keep the soil moist and prevent weeds from sprouting by denying them access to sunlight.
How to Water Lilacs
After planting, monitor your plants frequently, and water them once or twice a week, or anytime the top inch of soil becomes dry. While watering, count to 10 to make sure you’re providing each lilac plant with enough moisture. (If the plant becomes too dry, the leaves will start to droop.) You can reduce watering to every other week once plants have been planted and have had a few months to establish themselves. Lilacs won’t require additional water during the second growing season or later unless there hasn’t been rain in your location for a month or more.
How to Feed Lilacs
Lilacs should be fed Miracle-Gro Shake ‘n Feed Flowering Trees & Shrubs Plant Food after they have bloomed in the spring to encourage the development of robust roots. This plant food is jam-packed with nutrients for your plants, including kelp, earthworm castings, feather meal, and bone meal. These ingredients nourish soil bacteria, which in turn break down organic matter into nutrients for your plants.
How to Help Prevent Disease Problems with Lilacs
Powdery mildew is the main problem with lilacs, especially common lilacs. What’s the best approach to prevent this? Purchase and plant lilac cultivars that resist powdery mildew (check the plant tag or online description). Lilacs benefit from being planted in areas with good airflow. This fungus disease won’t respond to spraying, and it will finally go away on its own.
How to Deadhead Lilacs
Be sure to deadhead young lilacs as they start to bloom (this could take a few years!). Deadheading involves clipping off faded flowers at the base as soon as they start to droop and fade. In response, the plant will use more energy developing new flower buds for the upcoming spring.
How to Prune Lilacs
Although the newer, smaller lilac kinds require less trimming than the enormous conventional lilacs, all lilacs will grow more effectively and bear more flowers with regular pruning. Here are a few possibilities:
- Cut an older lilac shrub to 8 inches above the ground in late winter (March or April), then let it grow out if it isn’t flowering despite receiving plenty of sunlight. The following March, choose 8 to 10 of the best-looking stems, and reduce them by half. Trim the remainder to the ground. The following year, new blossoms should appear.
- Selectively prune 1/3 of the branches all the way back to the ground each year to revive shrubs that aren’t flowering well instead of chopping the shrub all the way down.
- Cut back branches to reduce size as soon as the shrub’s flowering has finished.
How is a lilac bush regenerated?
The common purple lilac is a hardy, dependable shrub that can grow up to 20 feet tall. Unfortunately, the lower, shady sections of lilac shrubs typically lose their leaves as they get older. Large, overgrown specimens as a result are frequently leggy and ugly. Pruning can restore or rejuvenate old, neglected lilacs. Home gardeners have two alternative pruning techniques to pick from.
Cutting the entire plant back to within 6 to 8 inches of the ground in late winter is one method of renewing a huge, overgrown lilac (March or early April). A significant number of shoots will sprout during the growth season as a result of this aggressive pruning. Select a few sturdy, robust shoots to construct the shrub’s framework, keeping a few of them, and cut off all the others at ground level in the late winter of the next year. To promote branching, head (clip) back the retained shoots to just above a bud.
Cutting back the overgrown shrubs over a three-year period is a second method for pruning mature lilacs. In late January, start the process by digging up and removing one-third of the big, old stems. The following year, trim out half of the remaining old stems (again in late winter). Additionally, trim out some of the recent growth. Keep a few healthy stems that are evenly spaced apart and cut off the rest. In the third year’s late winter, completely remove all of the old wood. It is also necessary to thin the fresh shoots more. This pruning technique should enable you to take pleasure in blossoms every spring because lilac wood must be three years or older before it blooms.
Within a few years, with the right pruning, an old, overgrown lilac can be converted into a robust, appealing shrub. Pruning should be a frequent component of the lilacs’ management regimen after they have been revived. By cutting a few of the oldest branches every three to five years, the shrub can be kept strong and healthy.
(This article, which first published in the Sunday edition of the Lincoln Journal Star Newspaper in February 2005, has since been amended. Consult the Terms of Use for details on how to copy this content and use any images or visuals.)
Does coffee help lilac bushes grow?
Use only a small amount of coffee grounds and grass clippings in your compost; they are good sources of nitrogen. The soil receives potassium from banana peels.
How often should lilacs be fertilised?
For the best shrub maintenance, fertilise once in early spring before new growth appears using a well-balanced (10-10-10) fertiliser. NOTE: This is the fourth article of a series of eight. Starting at the beginning will give you a thorough understanding of how to grow lilacs.
Are lilacs amenable to acid?
Lilacs prefer soil with a pH between 6.5 and 7.0, which ranges from slightly acidic to slightly alkaline. If the pH is either too high or too low, the bushes may suffer because the nutrients they require from the soil may not be easily available.
How much water do lilacs require?
A traditional flower garden, outdoor space, or decorative pot should all contain lilac plants as they are a staple flowering shrub. Zones 3 through 8 are suitable for growing these fragrant shrubs, and they require very little maintenance. Lilacs need at least 6 hours per day of direct sunlight to produce their best flowers. Lilacs benefit from regular watering after initial planting, throughout active growth seasons (spring), and during prolonged dry spells. Lilacs are fairly drought tolerant once they are established.
It is advised to water your lilac plant once every 10 to 14 days from spring till blooming is finished. The ideal irrigation for lilacs is deep, infrequent watering. Make sure the planting space or container has good drainage. These plants don’t appreciate having their feet wet and won’t bloom if they are overwatered. By saturating air pockets with water and reducing soil oxygen levels, excessive water can strangle the lilac tree’s roots. The first indication that the lilac is overwatered is the plant wiggling.
Should I prune my lilac bush’s dead branches?
A lilac shrub needs to be pruned every year once it has reached the age of two. Early summer is ideal for cutting grass because the flowers have already flowered and withered. Here are some tips for taking care of lilac shrubs and trees.
Lilacs produce the flower buds for the following season in the early summer, right after their blooms have faded. You run the danger of removing the budding buds if you delay trimming until later in the growing season.
This also holds true for lilacs that bloom twice a year, like Bloomerang Purple. After the bush’s initial bloom, you can prune it to promote new growth and more flowers in the second bloom, which occurs in early fall.
Lilacs eventually only bloom at the tips of their highest branches if allowed to develop naturally. Lilac bushes can be revitalised and made more visually appealing by pruning to maintain a balance between older stems and young blossoming branches.
Pruning a lilac shrub involves a number of techniques:
- First, remove any weaker branches and any dead, broken, or diseased stems. Branches should also be trimmed to avoid rubbing or crossing.
- Old stems that are thicker than two inches should be cut off. This controls the height of your lilac plant and promotes the development of new shoots. It is best to thoroughly remove the stems.
- Control sucker emergence. Suckers are fresh branches that sprout from the plant’s base. The main branches can be replaced by a few robust suckers, but any lesser suckers should be removed at the soil line to prevent them from robbing the plant of nutrients.
Last but not least, here are some general guidelines for pruning lilacs:
- Lilac bushes that are mature should only be pruned to a height of 6 to 8 feet.
- Aim for 10 to 12 primary stems, each of which should be between 1 and 2 inches thick.
- Never remove more than one-third of the bush with pruning.
- Older stems and fresh blossoming shoots should be balanced.
Which month should lilac bushes be pruned?
All lilacs should generally be clipped right away in the spring after they have finished blooming. Lilacs set their flower buds for the following year immediately after the current year’s flowers have faded, therefore trimming later in the summer or fall will result in the removal of most or all of the blossoms for the following year. The larger common lilacs as well as the shorter or more “shrub like” cultivars are all subject to this timing guideline. While the “when” of lilac trimming is rather simple, the “how” is a little more difficult. For the time being, we’ll refer to lilac pruning as either maintenance pruning or rejuvenation pruning to keep things simple.
Why is my lilac bush acting strangely?
Examine the branches for damage like as exit holes and sawdust, sap, and frass, which are indicators of insect infestation. Damage from damaged branches could be stopped by pruning them off. Next spring, as the lilacs begin to bloom, keep an eye out for the adults and place pheromone-activated traps (see Lilac borer).