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How to Fertilize Blueberries With Coffee Grounds Full Guide of 2023

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add coffee grounds to your blueberry bushesCan’t get those blueberries to thrive? You’ve tried every trick in the book – all the standard fertilizers, mulching, even singing to them at midnight under the full moon.

Before you rip ’em out in frustration, here’s one simple, free fertilizer you probably haven’t tried: coffee grounds.

Yep, that morning mud you savored just an hour ago has amazing soil benefits for acid-loving plants like blueberries.

Work some grounds around your bushes and get ready for a berry bonanza.

The nitrogen, acidity, and organic matter in used coffee grounds are just what blueberries need to liven up.

So brew up an extra pot tomorrow, and share that java joy with your languishing bushes.

Put those grounds to work, and you’ll be blueberry picking in no time.

Key Takeaways

  • Spread 1-2 cups of used coffee grounds around the dripline every 2-3 months during the growing season to provide organic matter and balanced nutrition.
  • Incorporate the grounds into the top 2 inches of soil, avoiding direct contact with stems.
  • Monitor and amend the soil pH monthly to maintain the ideal range of 4.5-5n5.
  • Limit applications to under 15% of total soil volume and taper off before dormancy to prevent excess nitrogen.

Why Put Coffee on Blueberries?

Why Put Coffee on Blueberries
You’re supposed to spread used coffee grounds around your blueberry bushes because the grounds provide nitrogen and other nutrients that will improve your plant’s health and growth. As you know, blueberries thrive in acidic soil with a pH between 4.5-5n5. Fresh coffee grounds have a pH around 6 while used grounds are closer to neutral at 6-8.

This makes coffee grounds great for adding some acidity and lowering the pH of your soil over time.

The nitrogen in the grounds is particularly beneficial – it promotes leaf and shoot growth leading to more fruit. Phosphorus and potassium in the grounds also provide key macronutrients blueberries need.

Beyond soil chemistry, the grounds improve moisture retention and aeration as they break down. The organic material contributes to a richer, loamier soil. This not only benefits the blueberries, but improves conditions for helpful microbes.

Start by applying 1-2 cups per bush, keeping the grounds an inch or two from the stems to prevent fungus. Reapply every 2-3 months. Check the pH periodically and amend if needed. The grounds help optimize your soil for better growth and yields.

How Much Coffee to Use on Blueberry Bushes

How Much Coffee to Use on Blueberry Bushes
You oughta spread no more than 2 cups of grounds per bush each time, partner. When using coffee grounds on your blueberries, it’s key to stick to the right amounts.

  1. Use 1-2 cups per mature bush. Seedlings need less.
  2. Keep it under 15% of total soil volume. Excess can be harmful.
  3. Start with small amounts and work up gradually.
  4. Reapply every 2-3 months during growing season.

The grounds provide nitrogen for growth, along with phosphorus, potassium, calcium, magnesium, and more. But too much too fast can lead to excessive acidity, which blueberries don’t like either.

It’s all about balance – giving your soil a steady nitrogen source while keeping the pH in the blueberry-friendly range of 4.

With the right technique, those coffee grounds will have your bushes bursting with juicy berries in no time.

When to Apply Coffee Grounds

When to Apply Coffee Grounds
There’s no better time than early spring to spread those coffee grounds ’round your blueberry bushes, buddy. When the weather starts warming up and new growth begins peeking out, it’s prime time to give those soil microbes a jumpstart by laying down a fresh layer of grounds.

The nitrogen in the coffee will get them active and working to unlock nutrients in time for your bushes’ growing season.

Come summer, you can do a lighter reapplication to keep fueling berry production. Just don’t overdo it – too much nitrogen mid-season can lead to lots of leaves but fewer fruits. Ease off the grounds as summer winds down so the plants can harden off for winter dormancy.

Season When to Apply Notes
Spring Early, around first growth Kickstarts soil life before rapid growth
Summer Occasionally, every 2-3 months Moderation to avoid excess leaf growth
Fall Gradually reduce amounts Allow hardening off before dormancy

Measuring soil pH with strips is smart too, partner – blueberries thrive in the 4.5-5.5 range. If the grounds shift pH outside of that, amendments like pine needles or peat moss can nudge it back. But applied wisely, coffee grounds enhance soil life and provide steady nutrients without disrupting pH much.

Your bushes will thank you for that wake-up call of nitrogen come springtime. Just sit back and watch ’em churn out those plump, juicy berries when the time’s right.

Applying Coffee Grounds Directly

Applying Coffee Grounds Directly
Y’know, sometimes the simplest approach is the best for gettin’ them grounds right where they need to be. Just grab a scoop and spread ’em around each bush, pokin’ em in the soil a bit if you’re feelin’ frisky.

Keep grounds 1-2 inches from the stem – you don’t wanna burn the roots.

Apply less than 2 cups per plant – too much caffeine content can overstimulate microbial activity.

Mix the grounds into the top couple inches – gets ’em interacting with the soil structure.

Reapply every 2-3 months – keeps that nitrogen flowin’ for your blueberry plants.

The low soil pH blueberries need means them grounds got plenty of fertility benefits to share. Drainage improves as they loosen things up over time too. Just monitor your pH and growth so the caffeine doesn’t overexcite the party down below.

With a judicious hand, your bushes will thrive with a direct helping of grounds. But don’t hesitate to compost excess amounts before applying more – slow and steady nourishment is the name of the berry game.

Composting Coffee for Blueberries

Composting Coffee for Blueberries
Wanna get more mileage outta them grounds? Compostin’s the ticket, partner. Takes more time upfront, but rewards with balanced nutrition in the end.

Mix spent grounds with carbon materials like leaves or sawdust. This evens out the acidity and nitrogen levels as it all breaks down. Aim for a C:N ratio around 25-30:1 by volume. Let that concoction cure for 2-4 months, aerating occasionally.

The finished compost provides a slow-release fertilizer that nourishes without overstimulating.

Apply 1-2 inches around each bush come early spring. Work into the top few inches of soil, avoiding direct contact with stems. The compost boosts organic matter, retaining moisture while improving drainage. Reapply after harvest, along with pruning debris.

Monitor your blueberry plant’s soil pH after applying. Composting helps balance acidity, but blueberries want a pH around 4.5-5n5. Use a pH meter to check levels. If needed, mix in some peat moss or pine needles to maintain ideal acidity.

With a bit of patience and planning, composted grounds provide balanced, slow-release nutrition. Your bushes reward you with abundant harvests, as the cycle of waste-to-resource continues.

Potential Issues With Coffee Grounds

Potential Issues With Coffee Grounds
You’d be wise to mind how much grounds you apply, lest the acidity or nitrogen become too much for your berries.

  • Caffeine can harm beneficial insects.
  • Excess nitrogen leads to weak growth.
  • Overly acidic soil damages roots.

While coffee grounds offer benefits, overdoing it carries risks. Limit your application to 2 cups per plant. Spread thinly over the soil surface, as concentrated piles create localized acidity. Monitor nitrogen levels, as too much causes excessive leaf growth and few berries.

Check soil pH after each application. A reading above 6 indicates too much alkalinity from the grounds.

Proper dosage and monitoring helps avoid potential issues. Pay attention to your plant’s response and test the soil pH. With careful use, coffee grounds boost blueberry growth and harvests. The acid-loving berries reward your stewardship with plump, abundant fruit.

Checking and Adjusting Soil PH

Checking and Adjusting Soil PH
It’s crucial to monitor the pH after adding coffee grounds to your blueberries. Those fresh, aromatic grounds do lower the pH, but likely not enough for the acidic ideal your berries crave. Arm yourself with trusty pH strips or a soil meter. Test different spots around each bush about a month after applying grounds.

Values above 6 signal excess alkalinity.

When the pH creeps up, reach for amendments like elemental sulfur or aluminum sulfate. These gradually acidify the soil as they break down. For quicker results, interplant evergreen needles or peat moss around your bushes.

Their natural acidity counteracts the coffee’s alkalinity. You’ll likely need smaller, frequent applications to nudge the pH down.

As the grounds decompose, released nitrogen promotes helpful bacteria. They aid nutrient uptake, fixing more nitrogen from the air into your soil. Such microbial activity depends on the organic matter you provide. Your coffee grounds are an excellent start.

Continue building a living soil web through companions like white clover, chickweed and comfrey. Their dynamic roots and nutrient cycling support your blueberries while adjusting pH.

Trust your observations, and let soil tests guide amendments. With thoughtful monitoring, coffee grounds can be a boon for your berries. The acid-loving bushes reward your diligent stewardship with robust health and abundant fruit.

Frequently Asked Questions (FAQs)

What kind of coffee grounds work best – caffeinated or decaffeinated?

Grounds drawn from any beautifully brewed cup will nourish your bushes equally, my friend.

Can coffee grounds attract pests like slugs or snails to my blueberry bushes?

Unfortunately, yes – the smell of coffee grounds can attract slugs and snails. Try scattering the grounds thinly and covering them lightly with mulch. Also, remove any slugs or snails that you see daily. Diatomaceous earth around the bushes also deters them.

Is it okay to use coffee grounds from coffee shops or restaurants?

Sure thing, those grounds will work just fine! They provide the same organic matter and nutrients. Simply spread 1-2 cups per bush around the dripline every 2-3 months, keeping it 1 inch away from stems.

Do I need to worry about the effects of caffeine on beneficial soil microbes?

Caffeine shouldn’t bother microbes, but high acidity could if you use too much. Go slowly when adding grounds, checking pH often, and your soil life will stay happy.

Can I use coffee grounds on container grown blueberries?

You can certainly use grounds on container blueberries. Like an eager barista, mix spent coffee into the soil to nourish your berries. The nutrients will perk up plants without over-caffeinating roots in confined pots.


Here are some tips for boosting your struggling blueberry patch. Before ripping it out, try giving the bushes a boost with used coffee grounds. Spread 1-2 cups per bush around the dripline, avoiding piling the grounds right against the stems.

The grounds provide nitrogen for growth and phosphorus for fruiting. They also help acidify and enrich the soil.

Avatar for Mutasim Sweileh

Mutasim Sweileh

Mutasim is a published author and software engineer and agriculture expert from the US. To date, he has helped thousands of people make their yards lush and thick.