9 Amaryllis Fertilizing Tips for the Best Blooms

Amaryllis bulbs are popular holiday gifts that expert gardeners and novices can enjoy. These stunning flowers are easy to grow indoors and in warm-climate outdoor gardens. Plant them in a small pot indoors or flower garden to get large brightly colored flowers during the cold season. 

Although true amaryllis are from South Africa, the ones we find in nurseries and garden stores are actually from the South American Hippeastrum genus. Within this genus are roughly 100 species and hundreds of diverse cultivars that produce enchanting flowers. 

To get the largest and healthiest blooms, follow a few fertilization steps. By doing so, you’ll give your flowers the fuel they need to produce radiant blooms. Below are nine fertilizing tips for the best amaryllis blooms this season.  

Fertilize When You Water

Like other flowers, amaryllis do well when you feed and water them at the same time. Fertilizer dissolves in water, making it easier for their roots to absorb the nutrients. It also makes it less abrasive for your bulb by diluting its concentration. 

Feeding your bulbs in between watering leaves clusters of fertilizer on the soil. Besides not absorbing the fertilizer evenly, the buildup could end up burning the foliage. The accumulated concentration can also overfertilize your plant once you water it, creating new problems for your blooms. 

For the best results, add the recommended amount of fertilizer to the soil. Water your amaryllis when the top layer of soil feels dry. Try not to water too much or the roots will become soggy, which could cause your blooms to lose their intensity. 

Use Balanced or High-Phosphorous Fertilizers

Amaryllis flowers love high-phosphorus food. Stick to a fertilizer with a higher ratio of phosphorus to nitrogen and potassium. Research shows that the best fertilizer for your amaryllis is a 10-20-15 (N-P-K) ratio fertilizer. N-P-K stands for nitrogen, phosphorus, and potassium, and having a higher middle number means you’re getting an extra boost of phosphorus to your soil. 

Bulbs like amaryllis need a lot of fuel to produce their majestic flowers. Fertilizers help ensure that your soil’s nutrient levels never dip below what your plants need. Phosphorus helps strengthen the roots and encourages blossoming. Potassium is also an important nutrient for blooming and‌ regulating nutrition and water movement. 

You can also use a balanced 10-10-10 or 4-4-4 fertilizer, but amaryllis flowers tend to perform better with a little more phosphorus. This nutrient promotes leaf growth, but too much may leave you with fewer blooms and foliage loss if you overfeed your plant. 

Consider Using Bone Meal

Bone meal is another alternative to artificial fertilizers that you can use to grow radiant amaryllis flowers. It’s made from steamed animal bones and contains high amounts of phosphorus and calcium. Bulbs use these nutrients to build healthy plant cells. 

Bone meal releases slowly and doesn’t give the quick boost of nutrients a liquid fertilizer gives. However, the nutrients in bone meal are released slowly into the soil and distribute themselves over time. 

Start applying bone meal by adding ½ teaspoon under the soil evenly. Keep it away from your  bulbs, concentrated around the roots. Slowly water your bulbs after applying until the soil is moist. You may not have to add more bone meal fertilizer until after your flowers bloom. 

Try Liquid Fertilizers 

Liquid fertilizers are magical for flower bulbs because they easily absorb into the soil and provide a boost of energy these hungry plants need. They quickly dissolve in water and spread to the root system evenly. You also won’t have to worry about buildup and undissolved clumps. 

Several organic liquid fertilizers on the market add balanced nutrients in a concentrated formula. It works as a quick nutrient boost and can help correct nutrient deficiencies immediately. Find a liquid fertilizer high in phosphorus and potassium. Always follow the instructions on the formula and feed your flowers when you water them.

Liquid fertilizers, such as liquid kelp fertilizers, can work wonders as long as they have a higher phosphorus content. These products are environmentally friendly and work as artificial fertilizers. Shop around and find a liquid fertilizer that works for you. 

Don’t Over Fertilize

Fertilizing is important for growing strong and healthy plants. However, you never want to overfeed them. Over-fertilized amaryllis will barely bloom and appear weak. If you see the signs of overfertilizing, it’s important to stop immediately. 

The first sign you’ve fed your plants too much is leaf burn. This appears as a brown spot on the edges of the leaves and soft plant tissue. This happens when the green plant cells come into contact with the concentrated fertilizer. 

Another common sign to watch out for is a crusty soil surface. Some fertilizers can leave a layer of salts and minerals on the soil surface. This can affect your plant’s ability to absorb water which results in yellowing leaves and wilting. 

As you can imagine, an over-fertilized amaryllis won’t have the energy to produce vibrant flowers. Always fertilize according to your product’s instructions. 

Avoid Underfertilizing

Amaryllis bulbs are sometimes healthy enough to produce flowers on their own. However, fertilizing them is a great way to get your blooms looking their best. It’s important to pay attention to your plants and know when they need more nutrients. 

Watch for stunted growth in your leaves and stems. If you have other flowers that are growing more vigorously, it could mean that they need more food. It could also mean your plants need more light. If they are already getting enough light, try using a balanced or high-phosphorus fertilizer. 

Another key sign of underfertilizing is yellowing leaves. This could be a sign of underwatering or even disease brought on by pests. In some cases, it could signal that they just need a little more nitrogen in the soil. 

The final sign is having a poor bloom. Unfortunately, this is a sign that your amaryllis flowers were malnourished throughout their growing period. Paying attention to the signs of malnutrition early can prevent this unfortunate outcome. 

Fertilize For the Next Season

After blooming, you may want to keep your plants alive until the next season. A great way to do this is by fertilizing. After blooming, trim the flower stems and keep your plants near a window. The leaves will keep growing as long as it’s getting enough light and water. 

Keep watering regularly to encourage growth. You can add a general all-purpose organic fertilizer with a balanced ratio. Keep fertilizing your flowers once every two to four weeks. 

Monitor your flowers as they grow. Keep an eye on their leaves for signs of overfertilizing or underfertilizing. As long as you’re feeding and watering your plants correctly, you should get another round of gorgeous flowers from winter to the following spring or summer. 

Stop Fertilizing Before the Dormancy Phase

Another way to encourage new growth the next season is to let your bulbs enter dormancy. To do this, remove the flower before it seeds. Stop watering and fertilizing your bulb and move it to a cool, dark place like a garage or shed. Remove the leaves up to two or three inches from the bulb’s surface and clean off the soil. 

The bulbs store energy for the next season during their dormant phase. During this time, it’s important not to disrupt them by exposing them to light or adding fertilizer. Keep your plant dormant for up to ten weeks until you see new growth form. 

When your plants are ready, replant them in a container with well-drained potting soil made for bulbs. Place them near a sunny window and give them consistent water. You should start to see new leaves appear quickly, signaling that the plant is ready for its normal feeding cycle. 

Fertilize After Dormancy

If your bulbs go dormant, start fertilizing your amaryllis bulbs only after you see new growth. Amaryllis bulbs are full of energy and ready to send out healthy leaves and bright flowers. When you wait until the new growth forms, you’re giving your plants enough time to get into their natural growth cycle. 

Feeding your bulbs before the leaves develop can kill the roots and harm the bulbs long term. The flood of nutrients burns the delicate roots before they mature. Once the flowers’ roots are damaged, the plants won’t be able to absorb nutrients effectively.