First considerations
Are your blueberries not producing this year or not as sweet as they once were? There are many factors to consider what could be going on, but first let’s talk about the basics of what will promote a healthy, happy blueberry bush.
Do you have any food available for your plants?
Before we get all worked up and go out buying expensive products maybe we can fix this using local inputs.
How do I tell if there is any food?
First, let’s go out with a hoe or shovel, push back any mulch in place and see if there is any broken-down organic material that our plants could be feeding from. Chances are if we are having production issues we have burned through this reserve. If you have not added any leaves, wood chips, compost, composted manure, pine needles, or sawdust to your bushes chances are they need food!
How often and how much food do my plants need?
We want to be adding 1-3″ of organic materials yearly to make sure we have composted organic materials that are ready to be mineralized by fungi and bacteria and exchanged for sugars with our plant roots. Blueberries evolved to grow in acidic environments and thrive in well-drained, acidic soils.
Rejuvenating a neglected bush
Maybe you inherited a blueberry bush and you are new to on how-to keep up with management. One of the first considerations is to aerate the soil. Especially if we have neglected to add any organic materials such as mulch, chances are that our soil has compacted and we may have competing weeds and even vines such as honeysuckle growing up our plants. Here is my group of blueberry bushes that have been neglected over the past 4 years. They had received pine shavings as mulch but the ground was compacted and the pine mulch was more or less used up. We also had a lot of honeysuckle roots competing for nutrients in the same area our blueberries are. This is not ideal and it was time for remediation.
Weeding and soil aeration of blueberries
As you can see in the photo above I have already started aerating the soil using a serrated edge garden hoe to break up compaction and remove all the honeysuckle roots that have competed with the blueberry bushes. It is okay if we nick some of the blueberry roots, but try to be a bit more shallow or careful as we get closer to the crowns of the plants. After some hard work hoeing, here is how our ground was looking post-wedding.
How far out to weed and breakup sod or compaction.
This will vary depending on the size and production method of your blueberries. In my case, we have 5 groups of blueberry bushes in a central location. In this instance, I wanted to have a nice 3-4′ ring around the outside to add my “plant food” free of competing weeds or grasses. My hoeing was much more shallow in the middle of the plants as there were way more blueberry roots here. I also avoided adding mulch and compost in this middle.
How to apply food or mulches
When applying compost or mulch, we want to avoid applying it near the base of a tree or shrub. An exception to this rule is pine needles. Doing so can affect the exchange of gases and damage our plants, but pine needles will not block gas exchange. This means we want to leave a 4-6″ perimeter around our crowns free of compost or smothering mulches.
What is the difference between compost and mulch?
Compost can be applied like mulch but generally, compost is considered a soil amendment as it can be mixed or incorporated in the soil as it is biologically active or broken down. Mulch on the other hand should not be worked into the soil, as it consists of inorganic and organic materials that need time to break down to become compost or biologically active.
Can mulches rob the soil of Nitrogen?
While you maybe heard that adding green mulches or mulches that are not first composted will rob nitrogen from the soil it shouldn’t prevent you from using mulches. Yes, indeed mulches can rob nitrogen from the topsoil but when using mulches on established trees and shrubs their roots are going to be less likely affected by a lack of nitrogen in the topsoil. This will help starve out weeds that compete with our plants. Eventually, the nitrogen locked up in the mulch will break down and be available to feed our plants.
Finishing Touches
In the photo above, you can see we have added a nice layer of compost along with wood chips as a mulch on top. I did not work the compost into the soil. I shoveled it out, avoiding the bush crowns. The plan is to head back out one day and rake up some pine needles to prevent weeds from growing around the crowns of my blueberry bushes.
Timing of application
For me, the best time to spend so much time with the blueberry plants is in winter. It is also an easier time to aerate the soil as there are long periods of moisture in the ground with the lower temperatures in Virginia.
Some sources advise early Nitrogen fertilization in early spring and second fertilization after berry harvest. The best way to accomplish extra fertilization is to rake back mulch and work the fertilizer into the soil. I am confident the cow manure in the compost will provide plenty of N for the upcoming season. The wood chips will continue to break down and add more organic materials or nitrogen down the road as well.
Where to get compost or mulches
First, look locally. Call around to some local cattle operations. If they are not raising vegetables there is a good chance they will be happy to sell you a nice load or even deliver for you.
For wood chips check out get-chip-drop, a free service to offer a dump location for arborists who have been doing tree work local to your location.
Another free source of mulch in cities is all the bags of leaves piled up in the suburban areas. Often, they love to pile up trash bags of unsightly mulch!
