Hyacinths produce some of the most fragrant and vibrant flowers. Hyacinths have long leaves that don’t look like the leaves of typical plants because they grow from a bulb rather than a seed. Leaf issues can occur with hyacinths so today I will explain what causes these and how to remedy them.
Not enough water, overwatering, poorly draining soil, and nutrient levels cause hyacinth leaves to turn yellow. To fix the yellowing of the leaves keep the soil slightly damp, treat spider mites with neem oil, and repot hyacinth in fresh ordinary compost soil.
Not all of these issues are life-threatening to hyacinths, it’s also important to note that in the autumn and winter the leaves will turn yellow as they die back and the hyacinth goes into dormancy. Below, I will explain the symptoms of each of these issues so you can identify what’s causing it and the appropriate remedy for each.
Not enough water can cause hyacinth leaves to turn yellow
When the soil is kept too dry for too long a hyacinth won’t get enough water. In plants that exhibit yellowing of the leaves because of underwatering the middle leaves are generally yellow. But, because hyacinths have overlapping leaves this measure can’t be used.
However, additional signs that underwatering is causing the issue is if the tips of the leaves start to go brown, and dry. After prolonged periods the leaves will also go completely dead and fall off. Lifting the entire plant out of the pot can also reveal this issue.
If it comes out easily you can use this method. As you hold the plant you can see whether the water is going all the way into the bottom of the soil, or only half or less of the soil profile is wet, while the soil at the bottom is dry and crumbly.
- Water the hyacinths so you can see water come out of the bottom of the pot.
- Poke a finger down into the soil to feel how wet it is, and water it more if it’s dry.
- Keep the soil damp but not waterlogged.
Too many nutrients in the soil or not enough
If you’ve potted your hyacinths in regular garden soil it can be a bit nutrient-poor. The pH of the soil can also be slightly too high or too low. Generally, using a regular bag of compost soil from the garden store gives the best results, and you don’t need to add any additional nutrients to the soil.
Adding additional nutrients using a bottle of plant feed, or fertilizer is generally too much for hyacinths and can cause the hairs on the roots to die off. This reduces their ability to uptake nutrients and transport them into the plant which causes the leaves to yellow.
The symptoms of not the soil not having enough nutrients are the color and texture of the soil. Light brown to orange, and sticky clumpy soil is nutrient-poor for hyacinths. Dark brown, loose soil is ideal.
- Repot your it into compost that you can make or buy from a garden supply store.
- Don’t add any additional nutrients to the soil.
Diseases – fungus and black spots visible on the yellowing leaves
Two main diseases can be visible on the yellowing leaves to indicate that this is causing it. These diseases are not life-threatening to a hyacinth so they can be left. Leaves with black spots should be trimmed where possible. Because hyacinths don’t have many leaves it’s generally best to leave them, as the hyacinth will still flower.
If you observe a powdery residue on the surface of the leaves this is caused by fungus spores that have blown onto the leaves and begun to grow. Which can also cause yellowing of the leaves. The fungus can be treated with a homemade spray using a mixture of 1 tablespoon of baking soda per one gallon (4.5 liters) of water.
- Trim off any leaves if the black spots are isolated to only one or two leaves otherwise leave it.
- Spray a fungicide or the homemade fungicide above onto the leaves after sunset.
Too much water causes root damage
Hyacinths don’t do well in waterlogged soil. This can occur if the holes in the pot are blocked and don’t allow water to flow out the bottom. Also, if you water them too often for example every morning and every evening the soil can remain too wet. Ideally, the soil should be damp but not soaking wet for more than a few hours.
When the water is too wet the roots begin to become soggy and don’t uptake water and nutrients as well which causes yellowing of the leaves.
- Water them just enough so that the soil is damp but not waterlogged.
- Ensure the water is flowing out of the bottom of the pot and isn’t pooling in the drip tray for more than a few hours.
- Pour off excess water in the drip tray.
Spider mites feeding on the leaves turning them yellow
Spider mites are a common cause of discoloration of the leaves. They turn an orangey-yellow rather than a bright yellow. Which will give you a tip-off that spider mites are what’s causing it. Spider mites are quite small so can be hard to spot. But, they will produce fine silk-like structures similar to spider webs on the underside of the leaves.
- Spray a mix of neem oil and water onto the plant or dab it on using a cloth, covering the affected leaves completely.
- Or spray it with an insecticidal spray from a garden supply store.
Soil is the wrong pH which starves it of nutrients
If you’ve made your own soil or used soil from your garden for your hyacinth it can be too acidic or alkaline. The pH of the soil breaks up or binds together different chemical elements. Making them less or more available to be absorbed once they are taken up by the roots.
Symptoms are yellowing of the leaves. Eventually, the leaves will turn brown and shrivel and the entire plant will die before it begins to flower. Or, shortly after it is fully grown and has flowered. Due to the short life cycle of hyacinth’s it’s generally best to re-pot them during the growing season.
Raising or lowering the pH takes 6 months to a year or more. So, it’s best to prepare the soil separately to be used at a later time. Rather than mixing in additives the existing soil the hyacinths are planted in.
- Do a soil pH test using a testing kit from the garden supply store it should be 6.0 to 7.0.
- If it’s too high or too low repot them into regular compost mix available at garden supply stores.
- To bring the soil pH down below 7.0 add organic material or sulfur into the soil.
- To raise the pH above 6.0 add crushed limestone, also called lime.