Fertilizer for blueberry bush

Fertilizing Blueberries – Learn About Blueberry Bush Fertilizer

Fertilizing blueberries is an excellent way to maintain the health of your blueberries. Many home gardeners have questions about how to fertilize blueberries and what is the best blueberry fertilizer. Below you will find more information about fertilizer for blueberries and how best to fertilize them.

When to Fertilize Blueberries

While there is not first or last date to fertilize blueberry bushes, the general rule of thumb is to fertilize blueberries in the spring before their leaves have grown in. This is so that the blueberry fertilizer has time to penetrate the soil and make it to the roots of the blueberry bush before it enters active growth.

You should be fertilizing blueberries once a year. Typically, they do not need fertilizing more often than this.

Types of Fertilizer for Blueberries

Blueberries like a higher acid soil. For this reason, you should be using a high acid fertilizer, especially in an area where you have had to amend the soil in order to lower the pH enough to grow your blueberries. When looking for a high acid blueberry bush fertilizer, look for fertilizers that contain ammonium sulfate or sulfur-coated urea. These tend to have a lower pH (higher acid).

Also try to use fertilizers that are higher in nitrogen, but be careful not to use a fertilizer that contains nitrates, such as calcium nitrate or chloride. Some blueberry plants can be killed by nitrates.

Blueberry plants are also susceptible to either iron or magnesium deficiencies. If your blueberry bush’s leaves turn a reddish yellow color, especially near the edges of the leaves, this is most likely a magnesium deficiency. If the leaves turn yellow with green veins, it is most likely an iron deficiency. Treat either of these problems with a nutrient appropriate blueberry fertilizer.

Natural Fertilizer for Blueberries

For organic fertilizers for blueberries, you can use blood meal or fish meal to provide nitrogen. Sphagnum peat or coffee grounds will help to provide acidity. Bone meal and powdered seaweed to fertilize blueberries can provide the potassium and phosphorus.

Before applying any blueberry fertilizer, whether organic or chemical, it is a wise idea to have your soil tested. While this may make fertilizing blueberries a little more tedious, it will help ensure that the pH of the soil and the nutrient mix in the soil is correct. It will help to prevent you from either over or under adjusting when you fertilize blueberries.

Fertilizer is usually applied to blueberries in the spring when growth begins and then again immediately after harvest. The exception to this is when fertilizer is injected into the irrigation system, in which case it is done on a weekly basis during the growing season (except during harvest).

Blueberry plants are sensitive to readily soluble fertilizers. Excessive amounts of these fertilizers can cause plant injury or death. Applying higher-than-recommended rates can be damaging, causing brown necrotic leaf margins or pale yellow chlorosis of leaves and low vigor, particularly when not enough water is applied. Do not concentrate fertilizer in small areas around plants. Do not use nitrate forms of fertilizer. Ammonium sulfate is the most often used nitrogen source. Ammonium nitrate and other nitrate-containing fertilizers should be avoided because nitrate ions are damaging to blueberries. Blueberries also respond well to fertilizers containing urea, diammonium phosphate and slow release-type nitrogen fertilizers. Urea nitrogen and organic forms of fertilizer such as cottonseed meal convert to ammonium, making them acceptable nitrogen fertilizer sources. Ammonium sulfate has an acidic reaction with the soil. Continual use of ammonium sulfate may reduce the soil pH below the desired range of 4.5 to 5.5. Urea nitrogen is less acid-forming than ammonium sulfate. If the soil pH is below 5, the urea form of nitrogen is preferred. If the pH is above 5, ammonium sulfate can be used. There are several urea-based fertilizers – ammonium sulfate blends with diammonium phosphate – on the market.

Mature plants, six years old or six feet tall, should be at the peak fertilization rate. If fertilizer is being applied with a spreader, try placing most of the material in the row area to reduce weed growth and maximize fertilizer use by the blueberry plant. As a general recommendation, apply 30 pounds per acre of actual nitrogen in the spring as a complete fertilizer (214 pounds of 14-8-8 per acre or 300 pounds of 10-10-10 per acre) plus 30 pounds of actual nitrogen per acre after harvest as urea (66 pounds per acre) or ammonium sulfate (142 pounds per acre). If growth is excessive (more than 18 inches of new growth per year), reduce the amount of nitrogen to 30 pounds per year.

For more information, see Dry Fertilization Table for Blueberries.

Contact your local Cooperative Extension Service office for information specific to your area.

Raspberry Fertilizing Needs – When To Feed Raspberries

Raspberries are a very worthwhile crop to grow. Store bought raspberries are expensive and bred to be able to travel long distances without squishing. If you want fresh, cheap berries, you can’t do better than growing them yourself. If you do grow them, of course, you need to know how to take proper care of them. Keep reading to learn more about raspberry fertilizing needs and how to fertilize a raspberry bush.

Raspberry Fertilizing Needs

Raspberry fertilizing needs are very basic and not hard to keep up with. Raspberry plant fertilizer should be heavy in nitrogen, although a balanced type is often preferred. For instance, the best fertilizer for raspberry bushes is a 10-10-10 fertilizer or actual nitrogen at a rate of 4 to 5 pounds (1.8 to 2.3 kg.) per 100 feet (30.4 m.) of row.

When to Feed Raspberries

Fertilizer for raspberry bushes should be applied soon after planting, once they’ve had some time to establish. Make sure to place it 3 to 4 inches (8 to 10 cm.) away from the stems – direct contact can burn the plants.

After your raspberries are established, fertilize them once per year every spring at a slightly higher rate than the first year.

Always fertilize your raspberry plants in the spring. Fertilizer, particularly when it’s heavy in nitrogen, encourages new growth. This is good in the spring, but can be dangerous in the summer and fall. Any new growth that appears too late in the season won’t have time to mature before the cold of winter and will likely be damaged by frost, which causes the plant unnecessary harm. Don’t be tempted to fertilize later in the season, even if the plants seem weak.

Avoid CommonMistakes

General

  • Avoid planting roots too deep or too shallow – they will not flourish.
  • Don’t leave soil loose around the plant roots – take care to pack it firmly.
  • Avoid planting near wild plants, or near plants whose origins are unknown.
  • Don’t water every day – water well, 1–3 times a week to maintain adequate moisture levels..
  • Avoid fertilizer burn. Hold off on fertilizing until plants are well established.
  • We advise you to plant all the roots of the plant without cutting the roots.
  • Avoid planting in the shade – All of our plants prefer full sun and will not thrive in shady spots. A half–day of full sun or more is necessary to ripen your berries.
  • we recommend a 10–10–10 fertilizer for all of our plants with the exception of blueberries which require our 17–6–6 or ammonium sulfate.

Strawberry Plants

  • Avoid planting in soils where previous crops have included strawberries, raspberries, potatoes, tomatoes, eggplants or peppers. These crops may harbor soil pathogens, which may affect your new plants.
  • Do not mulch using materials like decayed or wet leaves that tend to mat down and can smother plants.
  • Do not renovate day neutral strawberries.

Raspberry and Blackberry Plants (Brambles)

  • Don’t plant roots too deep.
  • Avoid planting in soils where tomatoes, potatoes, peppers, eggplant, or raspberries have previously been. These crops may harbor soil pathogens, which may affect your new plants.
  • Avoid planing green tissue culture plants until after danger of frost has passed.
  • Do not mulch brambles beyond the first year.
  • Do not mow down summer–bearing raspberries; they fruit on 2 year–old canes. Remove the canes that bore fruit the previous year.

Asparagus Plants

  • Be careful not to damage emerging spears when cutting below the soil surface during harvest.
  • Avoid planting in soil that doesn’t have pH between 7.0 – 7.2, because Asparagus require very sweet soil.
  • Do not add compost to soil until plants are growing.
  • Do not soak roots prior to planting.

Blueberry Plants

  • Don’t forget that Blueberries require an acidic soil with a pH between 4.5–4.8. A pH of 5.0 or higher is too high!
  • Do not use leaves or excessive sawdust as mulch. Either can limit or prevent rains from reaching the soil and plant roots.
  • Excessive sulfur can be toxic. Application of sulfur does not change the acidity quickly.
  • Do not apply fertilizer at planting.
  • Do not apply fertilizer in late summer or early fall. This could lead to new, succulent growth that is susceptible to winter injury and may lead to entry points for disease.
  • Blueberries can be adversely affected by potassium chloride. Do not use fertilizer that contains it.We do not recommend use of aluminum sulfate. Use elemental sulfur instead.

Ooh boy, summertime. There’s a lot to love about a summer day spent outside, isn’t there? Let’s set the scene:

Pollen wafts on the warm winds while the sun beats down, a hummingbird flits by and the hyperactive beating of its wings buzzes through your ears; you feel it more than you hear it. Warm soil beneath your feet and calico cloud shapes in the sky above.

If you’re like me, you’re probably in your bare feet with a beer in your hand. All that sounds pretty good, but nothing says (or tastes like) “summertime” like a berry patch in the backyard.

Far as I’m concerned, a berry patch is summertime incarnate. There’s something that is simply spectacular about a bunch of prickly brambles that’ll sting you just as fast as they give you some delicious fruit, and it all depends on how careful you are in approaching them.

I can’t even eat store-bought blackberries anymore; they taste like pale and bland imitations of the vine-ripened, freshly-plucked bunch of aggregate fruit you get straight from the garden.

And raspberries? Forget about it. They’re a different fruit altogether when they’re freshly picked, compared to those chilled and store-bought in convenient plastic containers.

The only solution to your edible woes is to plant your own berry patch. And it’s not a project for people unwilling to put in the hard work. Most berries require carefully prepared soils and growing areas to grow to their fullest, and they require regular care to do their best.

But for that brave, maybe foolhardy gardener, a berry patch will pay back the sweat and labor poured into it with the most delectable fruit you can imagine. Let’s see what really goes into it.

Breaking Ground

Location is everything.

Without exception, berry patches need access to full-sun conditions and good drainage in rich, fertile soil. Some plants have their own needs that need to be addressed (blueberries want a strongly acidic soil, for example), but there are a handful of essentials all berries need to have to grow their best.

Keep Those Wild Berries Away!

Probably the most important aspect of a berry patch is that it needs to maintain a good distance from any existing wild berry and bramble patches. This is an effort to prevent diseases and infection from transferring from the wild plants to your domesticated ones.

Recommended distances range from as far as 500 yards to a mere 50 feet. If you’ve got wild brambles growing in the perimeter of your yard and have no use for them, this is a great excuse to eliminate their presence and ensure the future of your own edible crop.

Full Sun and Good Soil

Like most fruit-bearing plants, berries need full sun to grow optimally. Some plants, like raspberries, will grow in part-sun conditions, but their crop yields will suffer for it. Most berry patches I’ve seen are located squarely in the center of a backyard, soaking up as much sun as possible to guarantee good growth.

Producing worthwhile and plentiful fruit requires rich, nutritious soil. In general, preparing a good berry patch is a multi-year endeavor. Initial preparations of the bed are vital to the long term health of the plants.

Organic Material

Plenty of compost, fertilizers, and other organic materials go a long way towards a successful berry patch. When first establishing a bed for berries, it’s important to completely remove the existing topsoil and amend it with good compost or manure.

Even after plants have been established, apply compost to the beds at regular intervals, once or twice a year. Because most berries do not do well with competition from weeds and other undesirables, healthy layers of mulch should be added as well.

Some berries have very specific needs. We’ll touch on those in the individual plants section below.

Space and Room to Grow

Even though berries will grow into dense patches of plants on their own, at the time of initial planting they need space and room to spread. Perennial plants like blackberries, raspberries, cranberries, and blueberries will spread out freely. Regular maintenance of dead canes or runners is required.

Strawberries, on the other hand, tend to survive for just a few years, typically 3-5, depending on variety. They need plenty of room to spread out and do their thing. However, their propensity for spreading out with baby plants (called runners) can quickly choke a patch of plants, ultimately resulting in minimized yields.

Which Types to Grow

We’ve got four favorites to shed some light on. It’s almost guaranteed you’ll find something tasty here.

Raspberries and Blackberries

Raspberries and blackberries are my favorite, and when I think of a berry patch, I see these guys in my mind.

Once the plants are established, they tend to happily take care of themselves and require just a bit of pruning in the springtime to remove old canes. Otherwise, you can sit back and watch those berries ripen.

Specific Soil and Planting Requirements

Raspberries and blackberries want to be planted in good, rich soil. Plant them thinly and with nice gaps between plants, about one foot apart each, to guarantee air flow and ease of weeding.

Because canes older than two years will die, having this extra space to work with in the beginning pays off greatly in the following years.

Keep the plants in full sun and try to keep them away from strong winds. They will produce in part-sun, but you’ll be disappointed in the volume at harvest time. And their leaves are sensitive to windburn.

Suggested Cultivars and Where to Buy

My all-time favorite berry is the Jewel raspberry, also known as the black cap.

Jewel Raspberry Plants in 5-Inch Containers

They’re beautiful, produce huge crops, and taste as good as any fruit could. These are available from Nature Hills Nursery.

Heritage Raspberry Plants, available from Nature Hills

When I think of raspberries, I’m usually imagining a Heritage berry. They’re perfect for snacking and baking and for turning into preserves.

You can find more of our favorite raspberry varieties here.

Black Satin Blackberry Plants, available via Nature Hills

As for blackberries, thornless varieties are popular in the garden.

Ouachita Blackberry Plants, available from Nature Hills

Try Black Satin for large fruit, some that will grow to be nearly as big as a golfball, or the Ouachita variety for a plant that doesn’t need a trellis.

Additional Notes

Raspberries will grow a new, green cane in one year. This new growth will then winterize and harden over to a more woody state, to produce fruit in their second year. These canes will be dead in the third year, and should be removed from the patch.

Some raspberry varieties can be cut down every year and allowed to grow again from scratch. For a more detailed explanation, read our full guide to growing raspberries.

Blackberries resent being dug up and fussed over. Let them spread and do their thing, and watch – in some level of shocked wonder – as their canes reach lengths of nearly twenty feet, topple over, and start a whole new plant.

Once your blackberries are established, just let them go and actively cut back at their growth. It’s a prickly job, but that’s part of the appeal of berry patches.

As a final note on this pairing: the two are susceptible to the same diseases. Some folks recommend putting a gap of anywhere between fifty and one hundred yards between the two types, but I’ve never done that.

In some of our clients’ yards, we have one run that is blackberries on the left 10 feet and raspberries on the right 10 feet. We’ve never had trouble with this, but it seems to be an issue for some folks out there.

Cranberries

I’m going to admit straight-up that I don’t like cranberries much, but they are tasty if you’ve got the palette for them. My attraction to cranberries is more focused on their lovely appearance, and the challenges involved in growing them. Also, they’re great in a cocktail.

Most folks start out with a patch about four feet by eight feet for cranberries. You’ll want to entirely remove all of the soil from this patch and replace it with peat moss, bone meal (about a pound), and blood meal (about 1/2 pound). It’s imperative to prevent the bed from drying out at any point, but not necessary to keep it soaked.

Plant cranberries about two to three feet apart.

They will produce runners regularly; it’s good to keep them growing, but you should be vigilant about preventing them from spreading outside of the bed and into the yard. Cut or pinch them before the runners spread too far.

Individual plants can be grown in a two-by-two-foot square, with soil replaced with peat moss.

True cranberries, or Vaccinium macrocarpon, can be difficult to find at local nurseries. But many offer highbush cranberry plants, or Viburnum opulus var. americanum, formerly known as Viburnum trilobum. A different species altogether, the American highbush variety produces fruit that very closely resembles your typical Thanksgiving favorite in both taste and appearance.

Actually a member of the honeysuckle family (rather than a heather like the true cranberry) it produces clusters of white flowers followed by fruit that matures in the fall. This hardy shrub will grow to be rather large, averaging eight feet wide by eight feet tall when it reaches maturity, often even larger.

American Viburnum Cranberry, 2- to 3-Foot Bare Root Plants

Birds love the berries too. Just be sure to purchase the true North American cultivar – European varieties (without the “americanum” at the end of their name) have inedible berries.

American highbush cranberries are available from Nature Hills Nursery. These plants will ship bare root, so make sure you’re ready to plant as soon as they arrive! I like to soak the roots of bare root plants in a bucket for an hour or two to prep them for planting.

Get ready for some work! To properly grow cranberries requires an investment of effort and time.

Plants don’t produce fruit until they are three years old, so unless you’re buying larger containerized plants, you’re in for a bit of a waiting period. However, once they start to produce, you’ll have plenty to pick

Did You Know?

The image of cranberries floating in fields is not for their health! Farmers will flood the boggy areas to make harvesting berries easier. But this is just for the harvest – no bog required if you want to grow this fruit in your backyard.

That’s right: there’s no need to flood the field so your cranberries will be saturated and swimming. They like moist growing conditions but don’t want to be in standing water. Regular watering (about one inch of water per week) partnered with well-draining soil is the way to go.…

Cranberries do not require fertilizing for the first two years of their growth, and too much fertilizer will cause them to grow out runners galore while sacrificing food production. Don’t overfeed these guys.

Add some sand to your cranberries each year. A layer of about 1/2 inch scattered around the bed is all you need. Do this in the springtime to encourage new growth and to help eliminate weeds and some insects.

Blueberries

I just can’t get enough fresh-picked blueberries when they’re in season. That also means I never buy them from the store, because they can’t come close to homegrown ones. I also love the wildlife that’s attracted to blueberries, and the ornamental appearance of the shrubs.

Blueberries crave acidic soil more than anything else.

I’ve known people who simply plopped a bush in their yard without any consideration for the pH of the soil, and they seem to get some pleasure from snacking on the meager harvests as they arise. But the people who enjoy larger yields will take care to amend their intended blueberry patch a year before planting anything.

Add acidic organic matter like pine needles, coffee grounds, and shredded leaves to a tilled bed and allow it to break down over a season. At the start of the next growing season, plant your blueberries. Re-apply pine needles as mulch at planting and repeat that process each year.

Using commercially-available acidifiers like Holly Tone works at a faster rate, and this product is available on Amazon. You’ve just got to deal with that stinky stuff if you choose to go this route.

Espoma Holly Tone, 18-Pound Bag, available on Amazon

DO NOT use fertilizers at planting. Wait about a month or so before you do. I’ve had the best luck with fertilizing most berry plants in small doses at a regular interval. Wait four weeks after planting to fertilize, then fertilize again every two months until the fall.

Fertilizers for blueberries have the benefit of being useful elsewhere in the garden. I’ve used this product from Dr. Earth for various clients who are all very happy with the results.

Dr. Earth Organic Acid Fertilizer, 4-Pound Bag, available on Amazon

Birds love blueberries, so it’s recommended you place a protective netting over them.

14 x 45-Foot Bird Netting, available on Amazon

I’ve got a reputation for saying, “Ah, the birds gotta eat too,” and I allow my avian buddies to have their fair share of berries. But not everybody likes birds as much as I do, so throwing netting over your blueberries or placing your plants in a fenced-in and covered area is the best way to ensure they aren’t picked at by wildlife.

There are a handful of types of blueberry: you’ve got highbush, lowbush, half-high, and rabbiteye.

The highbush blueberry grows better in slightly warmer climates, ideally zones 4-7, and reaches heights up to eight feet. Some varieties, like O’Neal, can grow up through USDA zone 10.

The highbush varieties can also serve as a part of an edible landscape plan and they have have beautiful red and yellow displays of fall foliage.

The lowbush blueberry prefers colder winters, thrives in zones 3-7, and rarely reaches more than two feet in height. It’s also known for having a more intensely sweet flavor than highbush varieties.

Half-high and rabbiteye blueberries combine features of the lowbush and highbush. The half-high species reaches more modest heights (two to four feet) and responds well to a cool winter. In warmer climates, the rabbiteye is a good choice. They produce tasty berries later in the summer.

Duke Blueberry Plants, available via Nature Hills

The Duke blueberry grows to about four to six feet tall. This is probably my favorite blueberry because of its robust taste and the amount of fruit it produces. It is a northern highbush, so it prefers a cool winter.

Sunshine Blue Blueberry Plants, available from Nature Hills

For a southern highbush try Sunshine Blue. They reach a height of up to four feet and produce berries the size of a dime. Expect a good crop of healthy plants!

Top Hat Blueberry Plants, available via Nature Hills

Top Hat is a good example of a lowbush blueberry. They reach a modest size and can easily be grown in a container, so you can grow blueberries even close to your kitchen.

For more of our favorite blueberry varieties to grow for home harvests, read our full guide.

Blueberries thrive in acidic soil, with a pH as low as 4-5. Add plenty of organic material to break down and prep the plants for their new acidic home.

Blueberries also perform at their best when they’re planted in pairs, or even larger groupings. Cross-pollination makes for bigger, better, tastier fruit.

The roots of most blueberries don’t grow deeply. Their roots are fibrous and have a tough time growing in compacted soil. Ideally, you’ll be able to dig out and till the soil where you’re planting your blueberries.

Amend the soil by adding peat moss, compost, sand, and the original soil into a mix. Ideally this will be a ratio of 4 parts peat moss, 2 parts compost, 2 parts original soil, and 1 part sand (4-2-2-1 ratio).

At the very least, add some peat moss and compost to the planting site.. (Hey, nobody said blueberries aren’t picky.)

Strawberries

Except for the fact that they’re a bit picky in terms of the soil they’ll grow in, strawberries are generally easy to grow, and can be placed in nice little pockets of your garden to fill in as edible ground cover, or to provide a nice splash of color. The foliage offers exceptional fall color, too.

Strawberries want to be planted in rich, sandy soil with good drainage. They do their best in raised beds or in garden patches with good drainage and regular watering. When planting them, ensure their roots are tucked just below the soil level and that their leaves are upright and out of the soil.

This sounds simple, but you’d be amazed to know how poorly I’ve seen strawberry patches planted. Strawberries can take a year to start producing anything worthwhile, and they do not like competition in the meantime. Diligent weeding is a necessity for a strawberry patch.

You can also plant your strawberries in a container. Almost any container with adequate drainage will do: an old wheelbarrow, a broken terracotta pot laid on its side, or even a colander could do the trick.

If growing in containers, use a standard potting mix with a bit of compost worked in. Allow the strawberries to just start drying out before you water them again.

Read more about growing strawberries in our complete guide.

In general, there are three varieties of strawberries to grow: day neutral, everbearing, and June bearing.

While day neutral produces two crops, typically in early summer and fall, the everbearing will produce continuously throughout the summer, and the June bearing produces just one crop towards the early part of each season, but it’s a big one.

The best choice for you depends on what you want to do with your strawberries!

If you’re interested in making a strawberry rhubarb pie (my new favorite pie recipe!), aim for a June bearing variety. You can even grow your own rhubarb with our tips.

If you want some reliable fruit throughout the entire summer, aim for an everbearing variety. More interested in veggies during the high points of summer? Try a day neutral strawberry instead to have early summer and fall crops!

The Allstar strawberry is a June-bearing plant, so you can expect one single, large crop. These have a nice flavor, and the winter-hardy plants do well in zones 4-10. The plants also have interesting leaves, toothed with three lobes.

Allstar Strawberries, 4.5-Inch Containers

These are available online from Nature Hills Nursery.

Ozark Beauty is a good choice for an everbearing variety of strawberry. I prefer the smaller fruits that pack in a huge punch of flavor, and that provide a longer window of harvest.

Everbearing Ozark Beauty Strawberry, 20 Bare Root Plants

The Seascape strawberry originated in California but it is capable of growing elsewhere in the country.

Seascape Beauty Everbearing, 10 Live Plants

These are vigorous with tasty fruit, the perfect candidate for a day neutral plant.

I’ve always planted strawberries in a grid pattern and like to combine different varieties in the same patch. I do this mostly because I like the variety in flavor, but it also provides a bigger window of when you can harvest.

Strawberry runners are going to spread out, so you’re going to want to try to cut out about half of these when you see them taking off.

Strawberries don’t want to be overcrowded, and too many runners mean little fruit production.

I’ve had gardens where strawberries aren’t bothered at all by wildlife, and then there are gardens where we’ve had to construct makeshift bamboo and bird netting cages around the plants to keep out chipmunks and groundhogs.

Keeping an active log of what visitors you have in your garden helps to prepare for inevitable troublemakers in the following seasons. And it’s nice to have this memento as well, a record of your garden’s history. Maybe take a couple pictures, or even try sketching something.

An essential element of your spring garden checklist is a garden journal. Sometimes a simple notebook works, but specially designed garden journals are made for this kind of project.

Let’s Get to Pickin’

It’s no secret that berry patches require a good measure of work to make them successful. But that’s half the fun, isn’t it?

Pouring your love and sweat into a patch of ground you’ve tilled, tested, and amended, then planting prickly things and producing sweet berries sounds like a worthwhile endeavor to me.

Most of the time it takes a while, at least a season or two, to get more than a few mouthfuls of berries, but when you do… well, that’s about as sweet as they get.

Try a nice border of chamomile to attract pollinators and offer their sweet smell while you’re working the ground. Chances are your herb garden is also located nearby, so don’t forget to check in on it and scratch a few things off your spring care checklist!

What’s growing in your patch of land? Feel free to ask questions and leave comments below! And check our our articles on growing mulberries and our favorite varieties of elderberries or our guide to planting berries in the fall for more homegrown-fruit-goodness.

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Product photos via Espoma, Dr. Earth, Red Earth Naturals, Hirt’s Garden, Hand Picked Nursery, and Nature Hills Nursery. Uncredited photos: .

About Matt Suwak

Matt Suwak was reared by the bear and the bobcat and the coyote of rural Pennsylvania. This upbringing keeps him permanently affixed to the outdoors where most of his personal time is invested in gardening, bird watching, and hiking. He presently resides in Philadelphia and works under the sun as a landscaper and gardener, and by moonlight as a writer. An incessant questioning of “Why?” affords him countless opportunities to ponder the (in)significance of the great and the small. He considers folksy adages priceless treasures and is fueled almost entirely by beer and hot sauce.

Fertilizer is usually applied to blueberries in the spring when growth begins and immediately after harvest. The exception to this is when the fertilizer is injected into the irrigation system, in which case, it is done on a weekly basis during the growing season (except during harvest).

Blueberry plants are very sensitive to readily soluble fertilizers and excessive amounts can cause plant injury or death. Higher than recommended rates can be damaging causing brown necrotic leaf margins or pale yellow chlorosis of leaves and low vigor, particularly where too little water is applied. Do not concentrate fertilizer in a small area around plants. Do not use nitrate forms of fertilizer. Ammonium sulfate is the most often used nitrogen source. Ammonium nitrate and other nitrate containing fertilizers should be avoided because nitrate ions are very damaging to blueberries. blueberries also respond well to fertilizers containing urea, diammonium phosphate and slow release type nitrogen fertilizers. Urea nitrogen and organic forms, such as cottonseed meal, convert to ammonium, making them acceptable nitrogen fertilizer sources. Ammonium sulfate has an acidic reaction with the soil. Continual use of ammonium sulfate may reduce the soil pH below the desired range of 4.5 to 5.5. Urea nitrogen is less acid forming than ammonium sulfate. If the soil pH is below 5, the urea form of nitrogen is preferred. If the pH is above 5, ammonium sulfate can be used. There are several urea – ammonium sulfate blends with diammonium phosphate on the market today.

Mature plants, six years old or six feet tall, should be at the peak fertilization rate. If fertilizer is being applied with a spreader, try to place most of the material in the row area to reduce weed growth and maximize utilization of fertilizer by the blueberry plant. As a general recommendation, apply 30 lbs per acre of actual nitrogen in the spring as a complete fertilizer (214 pounds of 14-8-8 per acre or 300 lbs of 10-10-10 per acre) plus 30 lbs of actual nitrogen per acre after harvest as urea (66 pounds per acre) or ammonium sulfate (142 pounds per acre). If growth is excessive (more than 18 inches of new growth per year) reduce the amount of nitrogen to 30 pounds per year.

See the Blueberry Fertilization Table for a program for fertilizing blueberries at various stages of maturity.

Liquid Fertilization

Fertilizer may be applied in liquid form through the irrigation system rather than surface applying dry granular material. Fertigation is the term used to describe applying liquid fertilizer.

There are some advantages to fertigation. Fertilizer is more efficiently used, it may be applied weekly in small amounts so that it is more available when the plant needs it, application cost is considerably less and nutrients more quickly reach the root zone in a soluble form.

There are also some disadvantages, including:

  • Irregular growth and possible damage to plants if the irrigation system is not working properly.
  • Specialized equipment must be added to the irrigation system.
  • Soluble fertilizer is relatively more expensive than granular fertilizer.

It is important that the irrigation system functions properly and all plants are receiving the same amount of water. If water distribution is erratic, some plants may be under fertilized while other plants may receive more than is needed. On sloping ground the use of pressure compensating emitters is necessary to insure that plants in the low areas do not receive more water than those on the higher ground.

Water pressure needs to be regulated so it is within the boundaries of the emitters and the flow rate through the pressure regulators should be adequate to supply the area being irrigated. It is important to have a backflow valve in the main irrigation line. This will prevent fertilizer solution from being sucked back into the well, community water system or other water source in the event of a power failure.

Follow up with a proper and regular watering program after liquid fertilizer is applied. Proper irrigation will allow the fertilizer to stay in solution until the plant has taken it up. If the fertilizer solution dries in the soil, the fertilizer within the solution becomes more concentrated and can become toxic if additional water is not applied. Regular watering between fertilizer applications help to wash the solution deeper into the root zone and encourages a larger, deeper and healthier root system.

Because liquid fertilizer is more efficiently placed and is more readily available throughout the growing season, it is easy to force more growth than is needed. Most fruit is born on the last eight to 10 inches of the previous year’s growth. If more than 12 inches to 14 inches of growth is generated, the extra growth should be considered excessive.

During the first four or five years, rapid growth is desired. However, if the plant grows too rapidly during the early years, it may become tall and leggy with only a small amount of fruiting wood. Some tipping of the upright branches may be necessary to produce the branching needed for maximum fruit production. Pruning should not be done after July 30 as fruiting buds are set on new growth produced in late summer.

Liquid fertilizer should be applied to blueberries by incorporating it into the watering program once per week. Irrigation water should be allowed to run for one hour to fill the irrigation system and moisten the soil at the root zone. The recommended amount of fertilizer solution should then be introduced into the irrigation water for one or two hours, and then fresh water applied for one hour. This method will allow the system to fill with water and moisten the ground, allow the fertilizer to be applied, flush the system of salts and wash the nutrients into the root zone.

See the Amount of Liquid Nitrogen for Blueberry Fertilization Table for more information.

An injector pump is the easiest and most reliable method for introducing fertilizer into the system. Most pumps will inject a certain amount of solution per hour. By knowing this ratio, it is easy to apply a recommended amount of fertilizer into the system.

Fertilizer rates are based on the age of the plants. The accompanying chart indicates the total annual nitrogen recommended for blueberries in the first five years after establishment. The nitrogen rate is broken down into a weekly application rate, which will allow 25 applications beginning in early March and ending in late August. Fertilizer applications should be discontinued during harvest and resumed after harvest. Stopping the fertilization program in August will allow most of the fertilizer in the soil to be used by the plant before entering dormancy.

Blueberry Fertilizer Recommendations: How to Feed Your Blueberry Plants Properly

The blueberry fertilizer you use to feed your blueberry bushes shouldn’t be just any old fertilizer.

That’s because blueberry plants have specific needs.

And that’s why the blueberry food you give to your plants should meet those specific needs.

Feeding your blueberries properly is key to enjoying bountiful harvests of big, plump, luscious berries from your plants – just like those in the photo below.

(Which I gobbled down right after snapping the photo!)

The payoff from well-fed, healthy blueberry plants!

First, Do No Harm When Fertilizing Blueberries

Blueberries tend to be vigorous and hardy plants. But they’re also very susceptible to being damaged from improper fertilization.

That’s because they have shallow, fibrous root systems. You can easily damage your blueberry plants by applying too much fertilizer – particularly if you’re applying a synthetic, salt-based fertilizer.

And blueberries tend not to need large quantities of fertilizer. So be very careful about the amount of fertilizer you give to your blueberry plants.

But you’ll also want to be very careful about the type of fertilizer you feed to your plants.

Blueberries require a very acidic soil pH to be productive and healthy. That’s why it’s very important that the blueberry fertilizer you use does not raise the soil pH.

So you’ll want to take a conservative approach to feeding your blueberry plants – both in the quantity and quality of the blueberry food you supply to them.

The Best Blueberry Food…

The best bet for feeding your blueberry plants? Choose a fertilizer that is mixed specifically for acid-loving plants.

It’s hard to find fertilizers that are manufactured specifically and exclusively for blueberry plants.

No need to worry, though: Fertilizer formulated specifically for azaleas will work just fine for blueberries, since azaleas and blueberries are closely related.

Azalea fertilizer is also often labeled for camellias and rhododendrons, and you can probably find it at most garden shops.

It’s also easy to find online. Here’s an example of an organic azalea fertilizer that would work just fine for blueberries.

Just Follow the Label Instructions

An advantage of using a fertilizer mixed specifically for acid-loving plants, like the example above, is that you can simply follow the label instructions for feeding your blueberry plants.

That will largely eliminate the guesswork in deciding how much and how frequently to feed your plants.

And most of these fertilizers will also provide a balance of macro and micronutrients. So you won’t have to worry about whether you’re feeding your berry bushes a balanced diet.

Other Fertilizers Recommended for Blueberries

Ammonium Sulfate: Ammonium sulfate is the most frequently recommended synthetic fertilizer for blueberries.

It’s particularly suited for fertilizing blueberries because it tends to lower the pH of the soil.

Urea: If your soil pH is naturally low (under 5.0), then you don’t really need to be concerned about lowering your soil pH for your blueberry plants.

In that case, a urea-based fertilizer will probably work best for you, since urea is not as acidifying as ammonium sulfate.

Be Careful!

When selecting a synthetic fertilizer for blueberries, be sure to only consider those that supply nitrogen in the ammonium form.

Avoid using fertilizers that supply nitrogen in the form of nitrates.

Nitrate-based fertilizers can damage or even kill your blueberry plants!

Organic Fertilizers for Blueberries

If you prefer to garden organically, blueberries will be a great addition to your garden because they have relatively few serious insect and disease problems (essentially none, in my personal experience).

And because blueberries require relatively low levels of fertilizers, it’s easier to supply their nutritional needs organically than it is for some other crops.

But if you’re using organic fertilizers, you still need to be careful to use only fertilizers that will tend to lower pH – or at least not raise it.

Cottonseed meal and blood meal are examples of acidifying organic fertilizers, and both are recommended for blueberries.

Be careful about using manure for fertilizer. Composted manure is great, but applying fresh manure is not a good idea (unless you apply it several months before planting).

How and When to Apply Blueberry Fertilizer

If you’re using a fertilizer mix that’s formulated for acid-loving plants, you’ll simply follow the label directions.

But if you’re using a general purpose fertilizer such as ammonium sulfate, here are some general guidelines for fertilizing blueberries:

  • The amount of fertilizer to apply will depend upon the type of soil you have, its fertility level, the type of fertilizer you’re using, and the age of your blueberry bushes.
  • Using ammonium sulfate as an example, apply 2 tablespoons in early spring, and another 2 tablespoons in late spring for first year bushes.
  • In the second and third years, apply 2 to 4 tablespoons in early spring, and repeat in late spring.
  • In the following years, apply ¼ cup plus 1 to 2 tablespoons in early spring, and then apply 2 to 4 tablespoons in late spring.

When applying fertilizer, sprinkle it evenly in a circular band under the drip zone of the plant. This is important for 2 reasons:

  1. Blueberries aren’t good at translocating nutrients from one side of the plant to the other. So if the bulk of the fertilizer is applied on one side of the plant, you won’t be feeding the entire plant effectively.
  2. Blueberries have shallow, close-to-the-surface root systems. That makes them susceptible to being burned by a concentrated application of fertilizer.

Make Sure That the Fertilizer Will Be Watered In…

Unless you can time your fertilizer application to fall shortly before a nice rain shower, be sure to water in the fertilizer.

If you’re using drip irrigation (which is an excellent means of watering blueberries), be aware that simply irrigating with your drip system won’t do an adequate job of watering in the fertilizer.

You’ll either need to get some rain shortly after applying the fertilizer, or run a sprinkler for a bit after applying the fertilizer.

Remember: Easy Does It!

Learning to apply the correct amounts of blueberry fertilizer can be somewhat of a trial-and-error process, because so many variables are involved that are unique to your garden soil and your environment.

But while you’re learning the ropes of how to fertilize your blueberry plants, always err on the side of applying smaller quantities of fertilizer.

You’re MUCH more likely to harm your plants by over-applying blueberry fertilizer than by under-applying.

A bountiful harvest!

Following the label recommendations of your fertilizer will get you off to a great start.

But even so, you might find that you’ll need to tweak your blueberry fertilization program just a bit.

It’s simply a matter of observing how your plants respond.

Over time, you’ll learn what works best for your growing environment.

It’s worth the effort, because the payoff will be buckets of plump, delicious blueberries!

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