The Best Time to Fertilize Daylilies to Encourage More Blooms – Expert Advice
Few perennials reward gardeners like daylilies. Their resilience, vibrant blooms, and easygoing nature make them a staple in many flower beds.
But if your plants produce more leaves than flowers, or their blooms seem smaller each year, fertilizing may be the missing step. Knowing when and how to fertilize daylilies can make the difference between average growth and a season full of stunning color.
In this guide, I’ll walk you through the best times to feed your daylilies, what type of fertilizer they prefer, and simple ways to get more out of each feeding cycle.
Conditions for Growing Healthy Daylilies
Before talking about the best time to fertilize daylilies, it’s essential to understand what helps these plants thrive. Healthy growth starts with the right growing conditions.
Sunlight
Daylilies need at least 6 hours of direct sunlight each day to bloom at their best. In hotter climates, they appreciate a bit of afternoon shade, but too much shade can reduce flower production.
Soil Type and pH
These perennials grow best in loamy, well-draining soil enriched with compost or organic matter. Aim for a soil pH between 6.0 and 7.0 — slightly acidic to neutral. If your soil is alkaline, nutrients like iron and phosphorus may become unavailable to the roots, causing pale foliage or weak blooms.
Moisture and Drainage
Consistent moisture is key during the growing season, but soggy soil can rot the crown. Well-aerated soil with organic mulch helps retain moisture while preventing compaction.
Temperature and Hardiness
Most daylilies thrive in USDA Zones 3–9, making them suitable for both cool and warm climates. They tolerate brief droughts once established but perform best when evenly watered and fed on schedule.
Expert Tip: If you’re unsure about your soil’s nutrient levels, get a soil test before fertilizing. It’s the most accurate way to know whether your plants need more nitrogen for leaf growth or phosphorus for stronger blooms.
When to Fertilize Daylilies
Fertilizing daylilies at the right time ensures nutrients are available when the plant needs them most. Feed too early, and nutrients may leach before roots can absorb them. Feed too late, and new growth could be damaged by frost or heat stress.
Let’s break down the ideal timing by season and growth stage.
Early Spring: The Primary Feeding Window
This is the best time to fertilize daylilies. Apply fertilizer when you see new shoots emerging and frost danger has passed. Early spring feeding helps jumpstart root activity, strengthens foliage, and builds the plant’s energy reserves before flower buds form.
Use a balanced slow-release fertilizer with an NPK ratio around 10-10-10 or 5-10-10. If you prefer organic options, compost, aged manure, or alfalfa meal are excellent choices. Scatter the fertilizer evenly around each clump, keeping it 3–4 inches away from the crown to avoid burn.
Give the plants a deep watering after fertilizing so the nutrients can move down into the root zone. If rainfall is expected soon, you can time the feeding just before rain for natural absorption.
Mid to Late Summer: After the First Bloom
Once the first flush of flowers fades, daylilies often slow down. Feeding again at this stage supports reblooming varieties like ‘Stella de Oro’ and keeps the foliage lush and healthy.
Use a low-nitrogen fertilizer, such as 5-10-10 or 3-4-5. The higher phosphorus and potassium encourage flower bud formation and strengthen roots without promoting excessive foliage.
Apply lightly — overfeeding in summer can stress plants during hot weather. Always water well after feeding.
Early Fall (Optional Feeding)
In warmer regions (Zones 8–9), you can apply one last, light feeding about 6–8 weeks before the first frost. Choose an organic or slow-release formula to help the plant store nutrients for winter dormancy.
Avoid this step in colder climates, where late fertilization can trigger soft new growth that may not harden before freezing.
Expert Tip: If you divide or transplant daylilies in spring, wait 4–6 weeks before fertilizing. Freshly disturbed roots are sensitive, and immediate feeding may cause root burn or stress.
Daylilies Fertilizing Schedule Chart:
| Season | Growth Stage | Purpose | Recommended Fertilizer Type |
|---|---|---|---|
| Early Spring | New shoots emerging | Build strong roots and foliage | Balanced slow-release (10-10-10 or compost) |
| Mid-Summer | After first bloom | Encourage reblooming and recovery | Low-nitrogen (5-10-10 or organic tea) |
| Early Fall | Before dormancy (warm zones only) | Root strengthening and winter prep | Organic compost, bone meal, or liquid kelp |
Expert Tip: The best time of day to fertilize daylilies is in the morning or late afternoon when temperatures are cooler. Avoid midday heat, which can cause fertilizer burn on moist foliage.
How to Fertilize Daylilies Correctly
Fertilizing daylilies isn’t complicated, but doing it right makes a big difference in how your plants perform. Many gardeners spread fertilizer near the crown or over dry soil, then wonder why it didn’t help. Daylilies have fibrous roots close to the soil surface, so timing, placement, and moisture all play a role in how well the nutrients are absorbed.
Step 1: Start with a Soil Test
Before adding any fertilizer, test your soil’s nutrient levels and pH. Daylilies prefer slightly acidic to neutral soil (pH 6.0–7.0). If the pH is too high, nutrients like phosphorus and iron become unavailable, even if you’re feeding regularly. A quick home testing kit or a local cooperative extension test will tell you what your soil needs.
If the soil is low in nitrogen, you’ll see pale leaves or slow growth. If phosphorus is low, you’ll notice fewer buds or smaller blooms. Knowing what’s missing helps you choose the right fertilizer ratio instead of guessing.
Step 2: Choose the Right Fertilizer Type
You have two main choices — granular slow-release or liquid fertilizers. Each works differently depending on your gardening style and soil conditions.
- Granular slow-release fertilizer (10-10-10 or 5-10-10): Best for established clumps. Nutrients release gradually over 6–8 weeks, supporting steady growth.
- Liquid fertilizers (such as fish emulsion, seaweed extract, or compost tea): Ideal for quick absorption during active blooming phases or container-grown plants.
- Organic options like bone meal, alfalfa meal, or aged manure build soil fertility naturally while feeding plants gently.
Avoid using lawn fertilizers or high-nitrogen blends (like 20-5-5). They can cause thick foliage growth at the expense of flowers and increase the risk of crown rot.
Expert Tip: If your soil already has good organic matter, you can feed once a year in spring. In sandy or poor soil, two light feedings (spring and mid-summer) are more effective than one heavy dose.
Step 3: Apply Fertilizer the Right Way
- Clear the soil surface: Remove old mulch or debris so fertilizer granules make contact with the soil.
- Measure carefully: Follow the label’s rate per square foot or per plant. For general feeding, about one tablespoon of balanced fertilizer per mature clump works well.
- Apply around the drip line: Spread the fertilizer in a ring around the base, 3–4 inches away from the crown. Avoid dumping it directly onto the center of the plant.
- Lightly incorporate: Use a hand cultivator or rake to mix granules into the top inch of soil. This prevents runoff and ensures even distribution.
- Water thoroughly: Always water after feeding. Moisture activates nutrients and helps them penetrate the root zone without burning the plant.
If you’re using a liquid fertilizer, mix it according to directions and apply it directly to moist soil. For container daylilies, feed every 3–4 weeks at half the strength of the recommended rate since nutrients leach faster from pots.
Expert Tip: Never fertilize when the soil is bone dry. Water first, wait a few hours, then apply fertilizer. This reduces the risk of root burn and helps nutrients travel deeper into the soil.
Step 4: Finish with Mulch
Once you’ve fertilized and watered, add a 2-inch layer of mulch around each plant. Shredded bark, straw, or composted leaves work perfectly. Mulch regulates soil temperature, retains moisture, and prevents nutrient loss. Keep mulch about 2 inches away from the crown to avoid rot.
Mulching after fertilizing also helps slow-release products break down more evenly, feeding your plants consistently through the growing season.
The Best Fertilizers for Daylilies
Choosing the right fertilizer is just as important as timing. Daylilies respond best to balanced or slightly phosphorus-rich blends that promote both foliage and flower development.
1. Balanced Formulas (10-10-10 or 5-10-10)
These provide equal or near-equal proportions of nitrogen (N), phosphorus (P), and potassium (K). Nitrogen fuels leafy growth, phosphorus supports bloom production, and potassium strengthens stems and roots.
Use these formulas for newly established daylilies or in fertile garden beds that already contain organic matter. A single early spring feeding often carries them through most of the season.
2. Bloom-Boosting Fertilizers (Low-Nitrogen, High-Phosphorus)
Ratios like 3-4-5 or 5-10-10 are ideal for mid-summer applications or for encouraging reblooming varieties. Too much nitrogen in this stage produces excess foliage, while extra phosphorus channels the plant’s energy toward bud and flower formation.
Expert Tip: If your daylilies grow near lawns, keep lawn fertilizer away from them. High-nitrogen runoff from turf products can overstimulate leaf growth and reduce flower count.
3. Organic and Natural Fertilizers
Organic fertilizers not only feed daylilies but also improve soil structure and microbial health. They provide nutrients gradually over time, helping prevent any chance of fertilizer burn.
- Compost or aged manure: Adds micronutrients and organic matter.
- Bone meal: Rich in phosphorus for bud and root growth.
- Alfalfa pellets: Encourage strong root systems and steady growth.
- Seaweed extract or kelp meal: Provides trace minerals and boosts stress resistance.
Mixing compost or aged manure into the top few inches of soil in spring gives a gentle, long-lasting nutrient supply that synthetic fertilizers can’t replicate.
Expert Tip: Alternate between organic compost feeding and low-nitrogen synthetic fertilizer each season for balanced nutrition and healthier soil over time.
4. Homemade Fertilizer Options
If you prefer natural solutions, you can make your own liquid fertilizer for daylilies:
- Combine one part compost or worm castings with three parts water in a bucket.
- Allow the mixture to sit for three to five days, giving it a stir now and then.
- Strain the liquid and use it as a nutrient-rich tea every 4–6 weeks during active growth.
This homemade fertilizer not only adds nutrients but also introduces beneficial microbes that help roots absorb minerals more efficiently.
Common Fertilizing Mistakes to Avoid
Even experienced gardeners make errors that limit flowering or stress plants. Here are the most frequent issues to watch for:
- Overfertilizing: Applying too much fertilizer can cause leaf burn and excessive foliage growth, resulting in few blooms.
- Feeding too late: Late-season nitrogen encourages soft growth that’s vulnerable to frost damage.
- Skipping watering: Fertilizer applied to dry soil can burn roots instead of feeding them.
- Wrong pH level: If the soil is too alkaline, nutrients remain unavailable, no matter how much fertilizer you apply.
- Ignoring drainage: Poorly drained soil can cause nutrient buildup and root suffocation.
Expert Tip: A dull bloom season doesn’t always mean your fertilizer failed. Sometimes, overcrowding or lack of sunlight is the real issue. Divide clumps every 3–4 years to maintain strong, productive plants.
What to Expect After Fertilizing
If you’ve applied fertilizer correctly, you’ll start to see results in 2–3 weeks. Foliage will appear greener and fuller, and flower stalks will become thicker and more upright. Over time, blooms will last longer and produce richer color.
In reblooming varieties, you might notice a second wave of flowers appearing 4–6 weeks after the initial flush. Keep the soil consistently moist during this period so nutrients move effectively through the root zone.
If growth still appears weak, check whether compacted soil or high pH is preventing nutrient absorption. Sometimes, improving soil texture with compost works better than additional fertilizer.
Now I’d love to hear from you…
Have you noticed a difference in bloom size or color after adjusting your fertilizing schedule?
Share your experience or questions below — your feedback might help another gardener get their best daylily season yet.
