If you are growing Dahlia, you would certainly be thinking should I fertilize my Dahlia, if yes, which is the best fertilizer, when should I fertilize and how should I fertilize my Dahlias.
For Dahlia, we would suggest fertilizer having lower Nitrogen. We would recommend Lilly Miller Bulb & Bloom Food 4-10-10 4lb.
Let us give you a complete guide on fertilizing Dahlia.
Should you fertilize your Dahlia?
Often the soil provides all the nutrients that a plant requires. This means that nutrients like Nitrogen, Phosphorus, and Potassium are available in optimum quantity in the soil.
The opinion is divided when it comes to the question of, should you fertilize your Dahlia as some say they are heavy feeders while others say, they do not need any extra nutrients.
But all agree that adding a layer of organic mulch helps in the growth.
If you are seeing signs of stunted growth, yellowing, or curling of Dahlia leaves, lack of nutrients can be the cause.
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Best NPK values for a Dahlia fertilizer
Dahlia like any other plant requires all the nutrients for optimum growth.
NPK represents the three micronutrients for the soil that the plant contains. Each number is the percentage by weight of the nutrient with respect to the total weight of the fertilizer.
The higher the value, high is the concentration of the micronutrient.
- Nitrogen (N) – Nitrogen helps in the growth of leaves on the plant.
- Phosphorus (P) – Phosphorus helps in root growth and flower and fruit development.
- Potassium (K) – Potassium helps move water and nutrients around in your plants. It also helps to keep away the pests and diseases.
Though we recommend you should choose different NPK value fertilizers for different seasons.
At the time of planting
We would not recommend any fertilizer at this time and applying a layer of mulching (of tree leaves) is enough to propel growth.
Though, you can apply an equal 5-5-5 fertilizer.
Before blooming
You would want to fertilize your Dahlia for the large flowers and not for bushy leaves.
As we have explained above, if nitrogen is more in fertilizer, it would mean bushier growth. Whereas, more phosphorus would aid in larger bloom.
Phosphorus is required for the overall development of the plant and its ratio should be kept almost the same as the highest constituent in the fertilizer.
You can apply the same at the end of June as most of the Dahlias in the USA start to bloom in mid-July.
Winter
Do not fertilize the Dahlia during winter as it would be difficult for the plant to sustain this new growth while it is trying to survive cold weather.
Best Home Made Dahlia Fertlizer
There are multiple ways you can make homemade fertilizers for Dahlia. Here are a few recommended ones.
Mulching of Tree / Grass leaves – Leaves of grass/trees have all the nutrients required for the plant. They are easily decomposed due to the high amount of water present.
Coffee Grounds – Since coffee grounds usually contain about 2% nitrogen, a third percent of phosphoric acid, and roughly 1% of potassium, they can be useful.
Though as they are high in nitrogen, you should not go overboard in applying this.
Further, while Dahlia like slightly acidic soil, coffee grounds can make soil quite acidic, so applying some eggshells can help.
Recommended Fertilizer that you can buy
| Fertilizer | NPK | |
|---|---|---|
| Lilly Miller Bulb & Bloom Food | 4-10-10 | Check on Amazon |
| Miracle-Gro Bloom Booster Food | 15-30-15 | Check on Amazon |
| Dr. Earth Bud & Bloom Fertilizer | 3-4-5 | Check on Amazon |
Lilly Miller Bulb & Bloom Food
We would recommend Lilly Miller Bulb & Bloom Food as the best fertilizer for Dahlia.
Features
- It has the right combination of phosphorus and potassium that enables blooming.
- Slow-release feeding
- Water Soluble
- Can be applied directly and then watering should be done.
- Contains natural ingredients
- Contains bone meal
- NPK 4-10-10
- This product is made in the United States
Contains
- Total Nitrogen (N) . . . . . . . . . . . . . . . . . . . . . . . . . . . 4%
- 0.8% Ammoniacal Nitrogen
- 0.7% Water Soluble Nitrogen
- 2.5% Water Insoluble Nitrogen
- Available Phosphate (P2O5) . . . . . . . . . . . . . . . . . . . 10%
- Soluble Potash (K2O) . . . . . . . . . . . . . . . . . . . . . . . . . . 10%
- Calcium (Ca) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6%
- Boron (B) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.02%
- Iron (Fe) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.10%
- Manganese (Mn) . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.05%
- Molybdenum (Mo) . . . . . . . . . . . . . . . . . . . . . . . . 0.0005%
- Zinc (Zn) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.05%
Miracle-Gro Bloom Booster Food
This is also one of the fertilizers that enable blooming in plants like Dahlia.
Features
- Contains high phosphorus for higher bloom yield
- Quick-release
- Works best for containers, window boxes
- Mix 1 tablespoon of Miracle-Gro for every gallon of water
Contains
- Total Nitrogen (N) . . . . . . . . . . . . . . . . . . . . . . . . . . . 15%
- 5.8% Ammoniacal Nitrogen
- 9.2% Urea Nitrogen
- Available Phosphate (P2O5) . . . . . . . . . . . . . . . . . . . 30%
- Soluble Potash (K2O) . . . . . . . . . . . . . . . . . . . . . . . . . . 15%
- Boron (B) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.02%
- Copper(Cu). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.07%
- Iron (Fe) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.15%
- Manganese (Mn) . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.05%
- Molybdenum (Mo) . . . . . . . . . . . . . . . . . . . . . . . . 0.0005%
- Zinc (Zn) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.06%
Espoma FT4 4-Pound Flower-tone 3-4-5 blossom booster Plant Food
Features
- It is a natural and organic fertilizer
- This fertilizer has low nitrogen and high potash
- It promotes blooming
- Environmentally safe
- No hazardous or toxic ingredients
Contains
- Total Nitrogen (N) . . . . . . . . . . . . . . . . . . . . . . . . . . . 3%
- 0.2% Ammoniacal Nitrogen
- 0.6% Other Water Soluble Nitrogen
- 2.2% Water Soluble Nitrogen
- Available Phosphate (P2O5) . . . . . . . . . . . . . . . . . . . 4%
- Soluble Potash (K2O) . . . . . . . . . . . . . . . . . . . . . . . . . . 5%
- Calcium (Ca) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5%
- Magnesium (Mg) . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5%
- Sulphur (S) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1%
