Yellow Leaves on Daylilies — Here’s Why!

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What causes yellow leaves on Daylilies?

One reason for discoloration is the leaves’ natural cycle. Additionally, persistent exposure to unfavorable conditions, such as inadequate sunlight, improper watering, unsuitable fertilizer, and diseases and pests, can lead to the yellowing of the Daylilies’ leaves. 

 

Reasons for Daylilies forming yellow leaves

 

Plant’s lifecycle

Naturally, all plants lose color and shed leaves when they complete their natural lifecycle. Similarly, the Daylilies turn yellow by the end of their growing seasons of summer and spring. 

Most of these flower species are found in the U.S. DA plant hardiness zones 2 to 10, with slight variations among the cultivars. 

While some Daylilies lose color in mid-summer, others may retain their vibrancy and characteristic shade throughout the growing months. 

As soon as fall arrives, the temperature begins to drop. 

The Daylilies mostly halt their development during this time because photosynthesis, the plants’ food manufacturing process, ceases. 

By late fall, mostly in areas with mild to severe cold, the DayLilies’ yellow leaves turn brown, dry up, and eventually drop around the base. 

New flowers do not bloom until the next blooming season. 

In regions with warm winters, the discoloration may occur later, in the early winters. 

However, the plant becomes dormant and no new growth is observed until the following spring. 

 

Insufficient sunlight

Like most of its fellow species, the Daylilies love to bask in the sun’s glory. 

They grow exceptionally well when exposed to full sun for four to six hours a day, planted in moist, well-draining soil. 

If placed in shade or inadequate sunlight, the Daylilies plant reacts by losing the attractive color of its flowers. 

Settings such as balconies, rooftops, and outdoor gardens are excellent choices for growing healthy and happy Daylilies flowers.

The sunlight does not only help the Daylilies plant to synthesize its food but also plays a major role in maintaining the flowers’ characteristic color. 

Hence, if your Daylilies don’t get enough sunlight, then this might yet be another reason why they might feature yellow leaves. 

When nurtured in the ideal environment, the Daylilies will brighten your day with their flowers for years. 

 

Incorrect watering schedule

Once established and mature, the Daylilies are considerably easy to maintain and care for. 

However, when young, they require extensive watering to develop a good and efficient root system.

If your juvenile Daylilies form yellow leaves that gradually turn brown, chances are you are not providing enough moisture to the plant. 

For a plant that likes staying in the sun for about one-third of the day, it is fair to say that it likes plenty of water. 

During the active growth seasons, spring through early fall, the Daylilies flowers’ soil should not be allowed to dry out entirely. 

Ideally, water the plant so that it receives about 1 inch of water every week, including rain. 

To prevent low moisture levels, add water when the soil’s top one inch feels dry to the touch. On the other hand, refrain from overwatering the plant as the damage is often irreversible. 

Excess water, directly or as rain, can cause root rot which is characterized by slimy and brown roots, instead of the normal firm and white form. 

The battered roots are unable to absorb nutrients from the soil leading to wilting and yellowing of the leaves. 

Please remember not to plant your Daylilies plant in a low spot that stays wet for long periods or accumulates water. 

 

Inappropriate (amount of) fertilizer

Fertilizer, whether used daily or once every six months, plays a significant role in the growth of flowering plant species. 

If fed infrequently or given the fertilizer with insufficient minerals, the Daylilies plant forms yellow leaves. 

Thus, it’s best to use a high-quality fertilizer with abundant nitrogen and potassium for best results. 

The former supports the plant’s overall structure and healthy metabolism, while the latter helps develop the characteristic color of the flowers. 

If the soil has optimal minerals, you do not have to fertilize as frequently. However, on average soil, add a feed in the springtime and again in late summer or fall. 

 

Diseases and pests

Daylilies are fairly resistant to diseases; however, two diseases pose a serious risk to the plant. 

The first disease is Leaf Streak, a fungal infection beginning at the leaf tips, and eventually, affecting the entire leaf. The disease-stricken leaves turn brown and die. 

Similar changes occur in Daylily Rust, another fungal infection leading to the discoloration of leaves. In addition, it also causes orange spots along the leaves’ undersides.

Pests such as thrips, winged pests, and spider mites can also cause extensive damage including silver-to-yellow speckles on leaves. 

To prevent all these problems, buy cultivars that are resistant to these diseases and pest attacks. 

Moreover, make use of a soaker hose or drip irrigation when watering the fine Daylilies; this keeps the foliage sufficiently dry. 

You can also maintain a space of approximately two to three feet to maintain good airflow and limit transferring of the fungal infection. 

However, if your plant has already acquired any disease or is infested, spray it with a fungicide or insecticidal spray containing myclobutanil, a disease-inhibiting chemical, that is diluted to about ½ fluid ounce per 1 gallon of water. 

Use the fungicide spray 3-4 times every 2 weeks for Leaf Streak, and once biweekly or as required when your plant’s infected with Daylily Rust. 

For controlling insects, mist the insecticidal spray every two weeks.

You can also follow the directions mentioned on the fungicide or insecticidal spray packing. 

 

Frequently Asked Questions about Daylilies

 

How often should I water Daylilies?

When young, you should water the plant every after a couple of days. When the plant matures, watering once to twice a week suffices. Please avoid underwatering and overwatering the plant.

 

How do I keep my Daylilies from turning yellow?

To maintain your plant’s good health and vibrant color, place it in full sun for four to six hours, water moderately, feed it in the growing season, and protect it from infections and diseases by taking good care of its hygiene. 

 

Can yellow leaves be reversed?

If you notice the yellowing of leaves early enough and begin watering correctly, the leaves may regain their characteristic color. However, if the damage is extensive, the plant is least likely to restore its original form. New growth may replace the old growth if placed in ideal conditions.