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Raspberries are a delicious fruit. They are relatively easy to grow as long as you have the right soil conditions. But will they be able to thrive in ericaceous compost?
Usually, ericaceous compost will be too acidic for raspberries. Ericaceous compost has a pH of between four to five, while raspberries prefer a range of 5.5 to 6.5. Because of this, you will need to add some soil modifiers, like lime, to make the compost more alkaline before you use it with your raspberries.
The acidity in the soil is one of the elements that will determine how well your plants will perform. Keep reading to learn more about the type of soil conditions raspberries need, so you can give them the best chance of growing strongly.
Ideal Conditions for Raspberry Plants
Let’s start by looking at some of the things that raspberry plants will need to be able to thrive. This can be broken down into a few areas.
pH Conditions
First, we need to look at the pH level they require. Raspberries will need slightly acidic soil. They can tolerate a pH level as high as 5.5. But they will perform best in more neutral soils. Often, you will need to strive for a pH level of around 6.5.
NPK Concentration
The next thing to consider is the number of nutrients that will need to be present in the soil for the raspberries to thrive. It’s best to use a balanced NPK fertilizer or compost. Because they will grow throughout the year, it’s a good idea to use a higher nutritional load. It’s best to get a 20-20-20 nutrient mix.
Soil Moisture
The third area that you need to consider is the amount of moisture in the soil. This will often depend on the time of the year. Here are the general rules to follow:
- Fruiting. When this plant is fruiting it’s a good way to water once or twice a week. You should aim to be keeping the soil damp. You can test this by sticking your finger a few inches into the soil. It should be moist.
- Dormant periods. After the fruiting has ended, the raspberries will enter a period of dormancy. During this time, you will be able to cut back on the amount of water you are giving them.
Will Ericaceous Compost Meet These Requirements?
Now that we know how raspberries thrive, we can compare this to the effect the ericaceous compost will be able to create. You should be able to find a mix that has strong water retention, allowing the soil to remain damp.
The biggest concern is the pH levels of ericaceous compost. This compost variety is known for being between four to five, though you can perform a pH test to find out the exact number. This type of compost will usually be too acidic for raspberries.
This can cause serious problems. Sometimes, if exposed to too acidic soil, the raspberry’s ability to absorb nutrients will suffer. There are a few ways this can manifest. Here are some of the warning signs you should be looking for:
- Stunted growth
- Lower than expected plant yield
- Brown spots appearing on the leaves
- Red or purple tinges appearing on new growth
- Yellow leaves, while the stems remain green
If you spot a combination of these symptoms, it’s good to perform a pH test. You should be able to find one of these in your local hardware store. All you need to do is take a small amount of soil and mix it in water. Then, add the strip. The color change will indicate the pH level of the soil.
Adjusting Ericaceous Compost to Suit Raspberries
The good news is that you can adjust the compost to make it more suitable for growing raspberries. In this area, your main focus should be raising the pH level. This is often the primary reason why raspberries will be struggling in your soil.
You will need to focus on adding a few elements to the soil to do this. Here are some of the things you can add:
- Lime. There are a few types of lime that you can use, depending on how aggressive you want to be. Avoid using quickened lime. This is designed to be used for concrete, so there is a chance that it can harden the concrete making it unusable. It’s best to stick to agricultural lime. Hydrated lime will work fastest, though there is a risk that you will burn your plants.
- Poultry manure. This can add a lot of nutrients while making the soil more alkaline. But, because of the high nutrient load, it should be used sparingly. You don’t want to risk burning the plants.
- Wood ash. This raises pH through the high amount of calcium carbonate that it will contain. This isn’t as effective as lime, so it will work best if you only need to make small adjustments.
- Bone meal. This is another element that will be able to raise pH, it will also promote flowering on your raspberry plants.
- Epsom salt. This won’t raise the pH. But it can be a good way of counteracting high calcium levels, which might be preventing your plants from taking in nutrients.
In most cases, you won’t need to wait too long to see the effects of these changes. It should become apparent after a few weeks. You can perform a pH test to track these changes.
Another potential is getting a compost mixture that has too many air pockets. The water will drain away too quickly if it isn’t dense enough. Thankfully, this is an easy problem to solve. You can increase the amount of peat moss in the soil. This will absorb the water.
You might also have to change the watering approach you employ. For example, if the soil is drying out too fast, you can use a drip watering system, so the water is constantly being added to the ground.
Other Compost Tips For Raspberries
While adjusting the ericaceous compost is a good place to start, there are a few other pointers to consider to make sure your raspberries thrive. These include:
- Add new compost regularly. Raspberries require fertile soils to grow strongly. Because of this, you will often need to add a new layer of compost. Do this every spring and autumn.
- Use plenty of mulch. It’s a good idea to add plenty of mulch to the garden. This will ensure that you can retain water within the soil. You will also be able to prevent the growth of weeds.
- Be careful about the type of manure you are using. It can be a good idea to use manure on your raspberries. It can add valuable nutrients to the soil. But you will need to be a little cautious about the type of manure. If the animal is sick, don’t use their manure. Though it’s rare, diseases might pass from animal to human through contaminated soil.
Generally, though, you shouldn’t have any problem growing raspberries. They are a hardy species. As long as a few basic soil conditions are met, they should thrive.
Final Thoughts
Getting the right soil for your raspberries is essential. Ericaceous compost is often rich in nutrients and can be good at retaining moisture. But, before you use it, add some elements like lime to reduce the pH level. As long as you take these steps and monitor the raspberries for any issues, they should be able to live a long life in this type of compost.
Sources
- https://www.gardenersworld.com/how-to/grow-plants/ericaceous-compost/#:~:text=Ericaceous%20compost%20is%20acidic%2C%20with,such%20as%20blueberries%20and%20rhododendrons
- https://homeguides.sfgate.com/ideal-growing-conditions-raspberry-plants-47418.html
- https://greenupside.com/4-ways-to-make-your-soil-more-alkaline-raise-soil-ph/#:~:text=To%20make%20garden%20soil%20more%20alkaline%2C%20add%20lime%20or%20dolomite,it%20can%20burn%20plant%20roots.
- https://www.yates.com.au/plants/fruits-and-citrus/raspberry/how-to-grow-raspberry/#:~:text=Raspberries%20like%20to%20grow%20in,Lifter%20Soil%20Improver%20%26%20Plant%20Fertiliser
- https://blog.bluelab.com/signs-that-your-plants-are-struggling-with-incorrect-ph