5 Causes of Raspberry Leaves Turning Yellow (Here’s How to Fix It)

A sudden change in the color of raspberry leaves can indicate that the plant requires immediate assistance. 

Although raspberries are a simple crop, they do need your attention. As a starting point, I recommend learning about why raspberries turn yellow.

While it’s normal to see raspberry leaves turn yellow at the end of the growing season, it’s a red flag if they do so in spring.

Raspberry Leaves Turning Yellow: what could be causing it?

A lack of nutrients in the soil or prolonged drought could be to blame for the sudden yellowing of the raspberry leaves. 

To avoid raspberry starvation, water the plant frequently and apply nitrogen fertilizers (in early spring, apply 40-50 g of ammonium sulfate or 20-30 g of ammonium nitrate per square meter). 

Viruses, fungi, and bacteria can also cause the leaves to turn yellow.

Moisture Deficiency In The Soil

The majority of the raspberry bush’s root system is close to the ground’s surface. As a result, the top layers of soil dry out quickly, especially if the soil is not mulched. 

This means that raspberries can suffer from a lack of moisture from time to time despite their general drought tolerance. 

This causes yellowing and drying of the leaves and fruit crushing. Therefore, three rules must be kept in mind when scheduling watering:

Water infrequently but abundantly, at least 1 bucket per adult bush. During the growing season, which runs from the end of May to the beginning of August, water your garden seven times: once in May, three times in June, and three times in July. The first half of August: Only if summer is hot and dry do you need to water raspberries.

You can reduce the frequency and intensity of watering by mulching the raspberry tree’s trunks.

Tip: Before the leaves turn yellow and dry out, you can tell if there is a water shortage because of their color. Colored leaves lose turgor and droop toward the bottom.

Raspberry Plant Needs Pruning

Overgrowth is the most common cause of yellowing leaves, and raspberries require regular and proper pruning. If you do not get this done promptly, the lower and middle tiers of leaves will not receive enough sunlight. 

The process of photosynthesis in the tissues is messed up. As a result, the leaf plates become a uniform pale green or yellow color. 

Even if you didn’t cut your trees in the spring, you could still get rid of this problem. This is what’s needed:

• Remove all fruiting shoots that have produced fruit;
• All root shoots more than 20 centimeters from the bush’s center should be trimmed.

There should be an ongoing effort to limit shoot growth to prevent thickening. 

Keep 6-8 shoots on each bush and remove the rest, depending on the variety. In addition to pruning, tying raspberries promotes normal photosynthesis.

Increased Soil Acidity Makes The Nutrient Unavailable

When raspberries are fertilized regularly and adequately, their leaves may still show signs of deficiency. 

This is because of the high acidity of the soil. As far as raspberries are concerned, the best pH range is 5.8 and 6. 

More acidic soils reduce the bioavailability of minerals and deplete their essential nutrients.

Applying the following remedies can help reduce the acidity of your soil:

• 300-500 g dolomite flour per 1 m2;
• Powdered lime (hydrated lime) – 200 to 400 g per m².
• Chalk-350-500 g per m².

Some mineral fertilizers, such as ammonium sulfate, increase soil acidity. As a result, they should only be used paired with deoxidizers.

Tip: Avoid using deoxidizers with organic fertilizers, resulting in nitrogen loss.

Deficiency of Nutrients in Soil

Fertilizer deficiency can also lead to leaf discoloration. There is a deficiency of:

As a result of nitrogen, the leaves become shallow and lose their green color. 

Cowpea fertilizer can be used to solve the issue. 500 grams of raw materials are mixed with 10 liters of water for each square meter and soaked for an entire day.

Iron: The deficiency of iron causes the veins to remain green. To fix the issue, chelated iron must be applied with watering.

Magnesium: the leaf plates turn entirely yellow and begin to dry out. In 15-day intervals, spray leaves with a 500g Epsom salts solution in 10 liters of water; repeat this 2-3 times.

Zinc: yellowing appears in tiny dots, which eventually turn yellow. 4 g of zinc sulfate is added to 10 liters of water for fertilization.

If your raspberries have yellow leaves, you know what to do. However, you should not jump to conclusions and suspect dangerous diseases right away.

Diseases That Cause yellowing of Raspberry Leaves

In the first place, yellowing of the leaves can occur if the Raspberry is infected with diseases that affect plant metabolism:

Raspberry Root Gall or Canker

Bacterial Root gall, also known as root canker, happens when the plant is grown in acidic soils or has been in the same place for more than 15 years. 

It spread from the infected soil to the plant through holes in the roots. Galls that form on the plant’s roots can grow up to 10-12 cm across (they can move to the root neck).

Tumors are soft and light gray at first. Then, the galls become thicker and darker as time goes on, but they stay the same color. So, the roots can’t get the water and nutrients from the soil as well as they used to.

It’s essential to check the bush’s roots if you see leaves that turn yellow and fall off, short shoots, or small berries that don’t have a good taste. If your suspicions are confirmed, follow these steps:

• Dig up the infected shrubs and safely dispose of them.
• For the next two to four years, do not plant anything in the area where sick plants were growing.
• Apply copper sulfate to the soil before you plant. This will keep harmful bacteria from spreading in the ground.
• Select plots for raspberry planting that have never been used for berry or fruit crops.

Sow mustard, lupine, or alfalfa on the plot before planting raspberries to improve soil quality. These plants improve the soil’s health.

Using a phosphorus-potassium fertilizer regularly can help prevent the growth of canker-causing bacteria in the root system.

Chlorosis of the Raspberry

Yellowing leaves is the most common symptom of a disease transmitted by a virus. Initially, the leaf’s veins turn yellow, then the entire leaf turns an irregular pale yellow, withering at the edges.

Young shoots are noticeably smaller, with fewer leaves; berries harden and dry out. Aphids and mites are the primary carriers of chlorosis.

Plants that have been affected should be dug up and burned. To prevent raspberry chlorosis on your homestead, follow these guidelines:

Choose raspberries that are resistant to the disease: Boyne, Cascade Delight, Killarney, etc.

To get rid of pests in the garden, treat it as soon as possible:

• Spray the bushes with Carbaryl and Diazanon garden insecticide, for example. As an alternative, you can use a natural or biological control method.
• Every 2-3 years, loosen the rows between the raspberry bushes by introducing humus (5 kg per 1 sq.m.) under them.
• Raspberry will benefit from watering under the root with a solution of poultry manure (1 part of manure and 10 parts of water).

As a precaution, disinfect garden tools with a 1% solution of manganese to prevent the spread of disease.

Rust on Raspberry

Many different kinds of plants get rust, a common fungal disease. Most of the time, infected plants can hurt the quality of the harvest and how well the plants can withstand the winter.

In hot weather, when there is a lot of humidity, it is the most dangerous thing to have.

In April and May, small red pads filled with spores appear on the leaves and stems of raspberry plants. These pads are filled with seeds. As the plant weakens, the leaves turn yellow and dry out.

Later, the spores spread, and the disease spreads through the garden as the pods break open. 

Spores start to build upon the underside of diseased leaves by the end of the summer, and this is when they begin to spread. 

If you notice any of these symptoms in your raspberry bush, take the following action:

• Cut out the infected parts before they spread. It will take two treatments spaced about 15 to 20 days apart. 
• Next spring, spray with copper sulfate or Bordeaux liquid should be sprayed on the plants even before the buds open.
• You can spray a raspberry tree with a solution of Bordeaux liquid or potassium salt, or ammonium sulfate before the buds start to open in spring. 
• Remove diseased shoots in the fall, rake leaves and burn them in the spring.

Now, if your raspberry leaves turn red and you have no clue read this article to learn what to do.

Look for pests first, then remedy the situation by watering, feeding, and treating. Only destroy the raspberries if your efforts are futile or if the yellowing of the leaves and other symptoms reoccur.

Allow your Raspberry’s leaves to turn yellow and wither when the cold weather arrives. I wish you success and abundant harvests!