When To Fertilize Amaryllis

Knowing when to fertilize amaryllis is the key to getting those spectacular, show-stopping blooms year after year. This guide will walk you through the simple schedule that makes all the difference.

These bulbs are powerhouses, but they can’t put on their big show without the right nutrients at the right time. Think of fertilizer as their fuel. Get the timing wrong, and you might get lots of leaves but no flowers, or a bulb that slowly weakens. Let’s get your amaryllis on the perfect feeding plan.

Your fertilizing schedule is directly tied to your amaryllis’s growth cycle. You don’t feed it when it’s dormant or in full bloom. Instead, you support the phases where it’s building energy for the next performance.

The Active Growth Phase: Your Main Feeding Window

This is the most important time to fertilize. It starts right after the flowers fade. Your plant will focus its energy on growing its long, strappy leaves. This leaf growth is how the bulb photosynthesizes and stores energy for next year’s bloom.

When to Start: Begin fertilizing about 4-6 weeks after the bloom finishes, as the leaves are growing vigorously.
What to Use: A balanced, water-soluble fertilizer (like a 10-10-10 or 5-5-5) works perfectly. You can also use one formulated specifically for bulbs.
How Often: Feed your amaryllis every 2 to 4 weeks during this phase. Dilute the fertilizer to half the strength recommended on the label to avoid burning the roots.

The Pre-Bloom Phase: A Gentle Boost

If you’re forcing a bulb for holiday blooms, a light feeding can help. Once you see the flower stalk emerging from the bulb, you can give it one or two weak doses of fertilizer. This supports the stalk development. Stop feeding once the buds begin to open so you can enjoy the flowers longer.

When to Stop Fertilizing: The Wind-Down

This is just as crucial as starting. As summer ends, you need to prepare your amaryllis for its rest period.

For garden-grown amaryllis in warm climates, stop fertilizing by late summer.
For potted bulbs you control, stop feeding in late August or early September.
This signals to the plant that it’s time to stop growing leaves and start shifting into dormancy.

The Dormant Phase: Absolutely No Fertilizer

When your amaryllis is dormant—its leaves have yellowed and died back—do not fertilize at all. The bulb is not absorbing nutrients. Watering and feeding during dormancy can lead to rot and will definitely not help with blooming.

Signs You Might Be Fertilizing Wrong

All Leaves, No Flowers: Often caused by not enough light, but can also result from fertilizing with a too-high nitrogen mix during the growth phase.
Weak, Floppy Leaves: Could indicate over-fertilization, which damages roots.
Brown Leaf Tips: A classic sign of fertilizer salt buildup in the soil.

Step-by-Step: Your Year-Round Amaryllis Fertilizer Schedule

Winter (Bloom Time): No fertilizer. Just water and enjoy the flowers.
Spring & Summer (Leaf Growth): Fertilize every 2-4 weeks with a half-strength balanced fertilizer. Give it plenty of sunlight.
Early Fall: Stop fertilizing. Reduce watering gradually to encourage dormancy.
Late Fall / Winter (Dormancy): No fertilizer, very little to no water for 8-10 weeks.
End of Dormancy: When you see a new flower stalk or leaf tip emerging, repot if needed, resume watering, but wait to fertilize until leaves are growing well.

Choosing the Right Fertilizer for Your Bulb

You have a few good options. The key is balance during the main growth phase.

Balanced Water-Soluble Fertilizer: The easiest choice. Look for equal NPK numbers (like 5-5-5).
Bulb-Specific Fertilizer: Formulated to promote strong root and bloom development.
Slow-Release Granules: You can mix these into the soil at repotting time. They provide nutrients steadily for several months, which simplifies your schedule.

Avoid high-nitrogen lawn fertilizers, as they promote leaf growth at the expense of flowers.

A Quick Note on Watering

Fertilizer and watering go hand-in-hand. Always water your amaryllis thoroughly before applying liquid fertilizer to damp soil. This prevents root shock. Also, ensure your pot has excellent drainage to flush out excess salts.

FAQ: Your Amaryllis Fertilizing Questions Answered

Can I use tomato fertilizer on my amaryllis?

Yes, you can. Tomato fertilizers are often higher in potassium, which can benefit flower development. Just be sure to dilute it properly.

How often should you feed an amaryllis in the summer?

During its peak summer growth, feeding every two weeks with a weak solution is ideal. If using slow-release granules, one application at the start of the season is often enough.

Should you fertilize amaryllis when it is blooming?

No, do not fertilize during bloom. The energy for these flowers was stored the previous year. Fertilizing now won’t help the current flowers and may shorten their life.

Why is my amaryllis not blooming even though I fertilize?

Lack of blooms is rarely due to fertilizer alone. The most common causes are not enough light during the leaf-growing phase, a lack of a proper dormancy period, or the bulb being planted too deeply. Fertilizer supports the cycle but doesn’t replace its key steps.

Is coffee grounds good for amaryllis plants?

It’s not recommended. Coffee grounds can make the soil too acidic and may promote fungal growth. A balanced fertilizer is a much more reliable and safer choice for providing the specific nutrients your bulb needs.

Troubleshooting Common Problems

Even with the best schedule, things can go a little sideways. Here’s what to do.

If you over-fertilize: You might see a white crust on the soil surface or pot rim. Flush the soil with plenty of clean water, letting it drain completely, to wash away excess salts. Skip the next scheduled feeding or two.

If you forgot to fertilize all summer: Don’t try to make up for it with a heavy dose in the fall. Just resume a normal schedule next growing season. The bulb may produce a smaller bloom or skip a year, but it will recover with proper care.

If the leaves are yellowing during growth phase: This could be overwatering or poor drainage, not necessarily a fertilizer issue. Check your soil moisture first before adding more nutrients.

Getting spectacular amaryllis blooms boils down to a simple rhythm: feed during the leaf-growing season, and stop to allow a rest period. By aligning your care with the plant’s natural cycle, you provide the support it needs to recharge its bulb. Stick to this straightforward schedule, and you’ll be rewarded with reliable, breathtaking flowers for many seasons to come. Remember, consistency is more important than any special product—your amaryllis just needs the right fuel at the right time.