Are Coffee Grounds Good for Lilacs? (a detailed answer)

Feeding your lilacs is a good practice and an act of love towards the plant. It doesn’t only support the growth of the lilacs but also aids flower production.

There are lots of organic and inorganic matters you can feed your lilacs with but are coffee grounds also good for lilacs?

The short answer is Yes. Coffee grounds are good for lilacs, especially those planted in nitrogen-deficient soil. However, the coffee grounds must be applied to the plant at the right growing stage, and watered properly so that the soil can effectively absorb the nutrients.

This article presents a detailed answer on whether or not coffee grounds should be used on Lilac flowers.

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What are Lilacs?

Lilacs are lovely flowering shrubs. The common variety of lilac is Syringa vulgaris. They are extremely hardy plants that thrive with very little care. Lilacs are lovely-looking plants with bright green foliage and pretty, fragrant magenta, pink, and white flowers.

Lilac bushes have several uses in the home garden. They can be used as border plants, flowering hedges, windscreens, or corner plantings. Because of their attractiveness, versatility, and hardiness, lilacs are widely beloved plants.

So, what do Coffee Grounds do for Lilacs?

Coffee grounds make a great fertilizer because they contain some necessary nutrients required for plant growth. Coffee grounds are a good source of nitrogen. They also help in decreasing the concentration of heavy metals in the soil and help to attract worms.

However, use coffee grounds sparingly.

Coffee grounds are highly acidic and should be reserved for acid-loving plants. But lilacs are less acidic and grow best in soil with a pH level of between 6 to 7.5. This is why you should use coffee grounds sparingly for lilacs.

Since coffee grounds create nitrogen, we do not recommend that you choose it as your organic fertilizer if your soil is already high in nitrogen.

When you apply coffee grounds to nitrogen-rich soil, the extra boost from coffee grounds can inhibit the growth of flowers.

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What Is the Best Fertilizer for Lilacs?

Now you know that though coffee grounds are good for lilacs, they are not the best organic fertilizer for lilacs, especially if your lilacs are planted in low-nitrogen soil.

So, what is the best fertilizer for lilacs?

Inorganic Fertilizers: Inorganic fertilizers contain different parts of nitrogen (N), phosphorus (P), and potassium (K).

According to experts, Lilac bushes benefit from an NPK 5-10-5, 5-10-10, 10-10-10, or 20-20-20 formulation. We recommend that you test your soil to find out the exact type of fertilizer that works best in your planting spot.

Apply inorganic fertilizer to your lilacs in their second year. Apply the fertilizer in early spring before new growth appears either by scattering the fertilizer on the soil around the base of the lilacs or by broadcasting.

Organic Fertilizer: A bone meal is a great organic fertilizer for lilacs. This is because it contains the lime that can sweeten acid soil and makes it more alkaline.

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It is also a natural plant food that is easy for the lilac to intake. Application of the organic fertilizer should be after temperatures rise in late spring or early summer.

Generally, the application of fertilizer to lilac bushes isn’t so necessary except after the first and second years of planting. Organic fertilizers are better for the environment because they release nutrients over time.

You can make your organic fertilizer by including slow-acting bone meal, fish emulsion, manure, or compost. Banana peels add potassium to the soil while grass clippings and coffee grounds add nitrogen to the soil. Don’t forget to use coffee grounds sparingly.

Important factors to consider when growing Lilacs:

What Kind of Soil Do Lilacs Need?

Lilacs love well-drained, fertile, and humus-rich soil that is neutral to alkaline (at a pH near 7.0). If your soil is in poor condition, you can add compost to enrich it. If your soil has an acidic pH, dig liberal amounts of compost into the planting site before you plant.

Read Also:- Are Coffee Grounds Good for Lilacs? (a detailed answer)

What is the Sunlight Requirement for Lilacs?

What is the Sunlight Requirement for Lilacs:- Six hours of sunlight per day is the minimum for healthy growth and maximum flowering

Pruning and Deadheading Lilacs

Pruning is very essential to bountiful lilac blooms. As the blossoms die, remove them from the lilacs by simply pulling them off with your hand. This is known as “deadheading.”

Deadheading is removing dead flowers from a plant to improve its appearance or stimulate further flowering. This should be undertaken no longer than a week to 10 days after the flowers have died.

Deadheading helps lilacs to redirect their energy to the development of flowers the following year rather than the formation of seed head this year. Also, prune your lilacs for height control just after they stop flowering. Waiting until winter or fall may cause diminished flowering in spring.

How to Mulch Your Lilacs

Mulching your lilacs helps with weed control and soil water retention. Mulch by spreading 2in. to 3in. of organic mulch like wood chips or peat moss around the base of your lilacs. Be careful to avoid contact with the base stems of the lilacs.

Slightly water when mulching because too much water can promote diseases. Also, keep the soil evenly wet around your lilacs. If you notice the yellowing of leaves, you may be adding too much water.

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Why Lilacs Aren’t Flowering

If your lilacs aren’t flowering, this may be due to several factors. It may be because your lilacs are too young. Most varieties of lilac don’t flower until they’re about three to four years old. In such a case, you need to exercise patience.

However, if age is not a factor, adding phosphorus-rich fertilizer to the soil can help speed up the flowering process. Another thing you can do to encourage flowering in lilacs is to pour an Epsom salt or sugar solution onto the plants.

Epsom salt can make lilacs grow bushier, produce more flowers, and even increase chlorophyll production along with providing vital nutrients, such as magnesium and sulfate to supplement fertilizer.

Also, your lilacs may not flower if you prune them at the wrong time. Since lilacs flower on old wood, you should prune them in the spring right after they’re done flowering for the year.

Perhaps, you’re pruning too much. Severe pruning can result in the loss of flowers for one to three years. Your lilacs may not flower if they aren’t getting enough sunlight.

Lilacs love sunlight and require at least six hours of direct sunlight every day else they may not flower well. If your lilacs are planted in a shaded area, you would need to transplant them to a better, sunny spot.

The low fertility of the soil can also contribute to the non-flowering of your lilacs. In such a case, you would need a specialized fertilizer for lilacs to help the plant produce healthy flowers.

For soil that is low in fertility, you may add some cow manure or a fertilizer that is low in nitrogen but high in phosphorous.


Unlock the secrets of enhancing lilac growth with coffee grounds! Discover how these discarded coffee remnants can be a game-changer for your lilac garden. Our blog explores the benefits, from enriching soil acidity to fostering healthier blooms. Dive into the world of gardening wisdom and make the most of your coffee grounds to transform your lilac haven. Elevate your gardening game with Plant Gardener’s insightful tips and maximize the beauty of your lilac blooms. Embrace sustainable practices and witness the magic that coffee grounds can bring to your flourishing lilac garden.

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If you planted lilac bushes and wondering whether coffee grounds are good for lilacs or not, you would have realized from the article above that coffee grounds are good for lilacs but should only be applied sparingly.

Coffee grounds are a good source of nitrogen but are highly acidic. Applying them in large quantities to your lilacs, which are neutral to alkaline, may harm the plant and inhibit flowering.

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