Blueberries and soil ph questions

General Fruit Growing
#1

I have never really delved much into blueberries and wish to try it.

My natural soil pH in-ground runs from 4.7 to 5.5 in various parts of the yard.

However, the best location as far as soil, sun, and drainage is adjacent to my vegetable plot which has been limed and amended to a pH of 6.5. I will test my soil first but how far away from that area would my plants need to be to keep the higher pH from “leaching” into my blueberry bed? I will note that the probable blueberry bed is slightly downhill from the amended vegetable garden, so water will flow towards it from there.

Soil is sandy loam with some silt.

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#2

You have sandy soil so lime is going down rather then spreading. Also Blueberry roots don’t go very deep. Check the pH six feet away. It should be your native 4.7-5.5. Perfect for Blueberries.

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#3

Blueberries prefer soil that is consistently moist. Sandy loam can tend to dry out. To save yourself some grief as well as extra work irrigating, you could amend the soil with peat moss, which is also acidic. By adding peat moss, you would kill two birds – moisture and pH.

A few years ago, I did this with my sandy loam: I dug a trench roughly 1’ down and 2-3’ wide. Then I filled the trench by adding a few inches of peat moss, then a few inches of soil, alternating layers and mixing a bit as I went along until the soil ran out. This produced a somewhat raised bed, which reduces the risk of root rot. Anyway, it has worked really well. Growth has been unbelievably robust.

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#4

Yeah blueberries love peat moss. If you prefer not to use peat moss you can use pine bark fines. It has a pH of 5 to 5:5 which is fine. I prefer it myself it’s not expensive in most nurseries. You need smaller particles. Large pine bark you could put through a chipper would work. Or you can be used as a mulch as is too.

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#5

everything said above and a good 3in.of mulch on top. even with my clay i still mulch every spring.

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#6

Per Strik’s research at OSU, organic mulch can raise potassium levels and decrease yield. Even a modest amount had an impact. Stick with sawdust, they say.

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#7

Thanks for the warning. But I’m confused – Isn’t sawdust organic? Is there a subset of organic that is a particular problem?

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#8

I’ll have to find the video. It’s a great resource for blueberries. Maybe it was compost?

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#9

That’s kinda a broad statement. I mulch with pine bark which is an organic mulch, but I highly doubt it increases any nutrient all that much except manganese which can be a problem.
The problem with sawdust when you use ammonium sulfate or urea is these high nitrogen fertilizers compost saw dust quickly. Pine sawdust is beneficial anyway.
This extension service bulletin is good on blueberries and pine bark.

I myself use a mix of pine and peat for soil in my raised beds I add some amendments too. I saw a study some time ago not sure if I have reference still? Anyway they tested various soil mixes and a 50-50 mix of pine bark and peat gave best results. So it is what I use.

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#10

i use whatever the arborist drops off. sometimes its conifer. sometimes deciduous or a mix.

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#11

I’ve had good success adding freshly fallen, mostly oak and maple leaves to my slightly raised bed blueberries. As the blueberries are entering dormancy, I add the leaves in the fall after people helpfully gather them in bags and set them by the curb. By the time the blueberries wake up in the spring the leaves are starting to decompose. I doubt this is an ideal system, but it’s very little work, does a good job of weed suppression, and the blueberries grow vigorously and flower profusely.

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#12

I use them too. Blueberries can handle organic breakdown decent. I do it to help protect and keep soil moist. I use coffee grounds sometimes. I add sulfur and iron about once every two years. Due at the end of this season. This helps take care of raises in pH by composting. I include pine bark in my mixes and at times decomposition of pine can lower pH. So I feel I have to check pH a couple times a year so I don’t get any surprises. It’s easy enough to lower or raise pH

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#13

2 words:

Pine needles

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#14

Jay, in the past I have purchased northern highbush blueberries from Doug Wiley at Truevine Ranch near Kansas City. I live in Nashville, TN. Doug always includes, with each shipment, specific directions on how to plant. I have had great success using the following instructions. Growing Instructions

Fertilizing is critical for success with our planting method. For more information on fertilizers we recommend go to Blueberry Fertilizer***

Site Selection

Select a very sunny location with easy access to water. Blueberries grow just as well next to your house as in the garden. Any soil that drains well is acceptable (clay, sandy, etc.). Sandy or rocky soil will require more water. Blueberries do not like “wet feet” so avoid low areas and locations receiving excessive runoff during periods of heavy rain.

Blueberry plants grow up to 6 feet high and 3 feet wide and live for 30+ years. Space plants 3 feet apart for a hedge or 5 feet apart if you want to walk around the plant. Space rows 10-12 feet apart. Blueberries are self-pollinating. For optimal cross-pollination blueberries require at least 2 plants. This can be the same variety or a different variety.

Varieties

# Variety # 2012 USDA Zones # Ripens
# Duke # 4 - 8 # Early # America’s #1 planted early season variety.
# Reka # 4 - 8 # Early # Very flavorful fruit, cold hardy, and more drought tolerant.
# Bluecrop # 4 - 8 # Mid-Season # America’s #1 planted mid-season variety.
# Liberty # 4 - 8 # Late # A popular variety for it’s flavor and vigorous growth.
# Elliott # 4 - 8 # Very Late # America’s #1 planted very late season variety.

Planting

Purchase 2 cubic feet per plant of Canadian Sphagnum Peat Moss available in “bales” from garden centers. Canadian peat moss has the lowest pH which is ideal for blueberries. Dig a hole 20 inches in diameter and 15 inches deep (cylinder shaped, not a cone or a bowl). Remove all the native soil. Mix the peat moss thoroughly with 5-7 gallons of water until all peat moss turns dark brown and the consistency of thick mud. A wheelbarrow works very well for mixing. Re-fill the entire hole with moistened peat moss. Plant your blueberry by making a hole in the peat moss. The top of the blueberry root ball should be level to the native soil line. Do not put any native soil in or on top of this hole filled with moist peat moss. Stake the plant if needed the first growing season. After that time, the plants should be sufficiently rooted and not need staking. Fertilize and mulch as described below. If you are unable to plant soon after delivery keep the root ball moist. Do not submerge the root ball in water.

For fall planting it is common to see some wilting when the plants arrive. Water the root ball immediately and plant within 48 hours. Do not fertilize your blueberry plants until March allowing them to go dormant without any new growth. It is also common for blueberry leaves to gradually show brown spots and red/yellow coloring as fall progresses. Blueberry leaves should drop off in November and December.

For container growing you will need a container with good drainage that is 20-24 inches in diameter and 15-18 inches deep. The downside to planting in containers is that more frequent watering is required. Plants will typically need to be watered daily in the summer, 3-4 times a week in the fall, and 2 times a month in the winter. Container growing is not recommended for USDA plant hardiness zone 4.

Watering

Blueberries are shallow rooted plants that need to stay moist but not soggy. Water requirements vary, especially as plants mature. Keep plants moist. During the heat of the summer it is common for plants to need water 2-3 times per week. The first sign a plant is too dry is the wilting of newer growth. Leaf edges turning brown shows the plant has been too dry. The first sign a plant is too wet is yellowing leaves. Continue watering until Thanksgiving or first snow. Lack of water in fall kills blueberry plants.

Mulching

Each plant needs a minimum 30 inch diameter of thick mulch to conserve moisture and prevent weeds. We recommend a 3-5 inch layer of pine bark as the optimal mulch. Avoid using cedar or black walnut.

Fertilizing

Fertilizer requirements vary, especially as plants mature. Mix 2 tablespoons of Jacks Classic Acid Special or Peters Professional Acid Special fertilizer or a generic version with 1 gallon of water. Apply fertilized water in a 6 inch ring around the base of each plant at least 1 time per month from March through mid-August. During summer months you can fertilize up to 3 times a month for more growth. If blueberry leaves have small red spots it often indicates the need for fertilization. As plants mature you can increase the volume of the mixture used but do not increase the fertilizer to water ratio.

For organic fertilization use Holly Tone (a granular/slow release) at a rate of 1 cup once a month or horse manure tea (5 parts water to 1 part manure) 1-2 times per month March through early August.

Pests

Blueberry plants are seldom bothered by bugs or diseases that require a spray here in Kansas City. A solution of 1 part dish soap to 10 parts water is effective against many insect pests. There are many organic and low toxicity products labeled for Japanese Beetles. Carefully read and follow the directions.

If rabbits are prevalent, use a 1 foot high fence around each plant until plants are at least 4 years old. If birds or deer are prevalent, we recommend using 1/2 inch square black plastic “bird netting" available at garden centers. Start netting when the first berry turns blue. Drape the netting over the plants and let it drag on the ground. Take the netting off when the fruit has been picked. Deer tend to be more prone to graze on blueberry plants in the fall and winter.

Pruning

Blueberries mature at 6-7 years of age looking like an ornamental hedge plant up to 6 feet high and 3 feet wide. You are welcome to shape or prune the plants whenever you would like. We do not recommend pruning the plants until they are 9-10 years old.

Harvesting and Handling

Fresh blueberries last for up to four weeks in the refrigerator. Blueberries can be frozen for up to one year. Do not wash blueberries before freezing them. Place them in freezer bags, freeze, and wash them when you are ready to use them.

Flavorful Hints

Duke blueberries have a great flavor and will become sweeter with refrigeration. Elliott blueberries need additional time on the bush after they have completely turned blue. Sampling and waiting a week or so after being fully colored yields a sweet berry.

#15

All this discussion about mulching blueberries is great. One of the ideas about mulching any production plant, even fruit trees, reminds me of my fight with the meadow shrews (voles) over the past several years. In fact, I just lost two blueberry bushes to them. I realized too late that I mulched too close to the center of each bush. I went out and pulled the mulch away from each and every bush I have in the ground, leaving about 6-8 inches of bare area around them. Shrews don’t like being out in the open.

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