Best Fertilizers for Acid-Loving Plants (2026)

Azaleas, rhododendrons, blueberries, camellias, hollies, mountain laurel and many evergreens all want soil in the 4.5 to 6.0 pH range, and they want a fertilizer that feeds them without pushing the soil toward neutral. The product most gardeners reach for is Espoma Holly-tone, a slow-release organic 4-3-4 with added sulfur, and for good reason: it is gentle, hard to overdo, and made specifically for these plants. Below we compare the acid-plant fertilizer listings on our Amazon shelf, which come down to Holly-tone in different bag sizes, Berry-tone for fruiting shrubs, and two bundles that add pH test strips. After the picks, a buyer’s guide explains feeding rates, timing, when you need sulfur instead of fertilizer, and where ericaceous compost fits in.

Part of our Composting & Soil guide →

In this guide

1. 1. Espoma Holly-tone 4 lb — Best Overall for Acid-Loving Shrubs
2. 2. Espoma Holly-tone 8 lb — Best for a Full Foundation Planting
3. 3. Espoma Holly-tone 50 lb — Best for Hedges and Large Borders
4. 4. Espoma Berry-tone 4 lb — Best for Blueberries
5. 5. Holly-tone 18 lb with pH Test Strips — Best for Checking pH as You Feed
6. 6. Holly-tone 36 lb Bundle — Best Bulk Bundle
7. What to Look For in a Fertilizer for Acid-Loving Plants
8. Which Pick Fits Your Yard?
9. Frequently Asked Questions

Urban Lotus Project is reader-supported. When you buy through links on our site, we may earn an affiliate commission at no extra cost to you.

How we compared: we compared 6 current Amazon listings on what each listing states (analysis, sulfur content, intended plants, bag size and extras). We did not test or handle the products, and availability changes.

1. Espoma Holly-tone 4 lb — Best Overall for Acid-Loving Shrubs

Best overall

Why We Like It

• Formulated specifically for acid-loving plants
• Sulfur helps hold soil on the acidic side
• Organic nutrients release slowly and gently
• Ready to use with no mixing

Specification	Details
Analysis	4-3-4 with 5% sulfur
Form	Granular, natural and organic, with Bio-tone microbes
Labeled plants	Azaleas, hydrangeas, rhododendrons, blueberries, evergreens, strawberries, camellias
When to apply	Spring and fall for shrubs; early and late spring for berries
Bag size	4 lb

Espoma Holly-tone 4 lb — compressed specs

The 4 lb bag is the right starting point for most homeowners with a handful of azaleas, a couple of hydrangeas and maybe a blueberry or two. The listing describes the same 4-3-4 analysis with 5% sulfur as every other Holly-tone bag on this shelf; what changes from pick to pick is the quantity and what comes in the box. The relatively low nitrogen is a feature, not a weakness: azaleas and rhododendrons have fine, shallow roots that scorch easily under strong synthetic feeds, and a slow organic release matches how they grow.

The listing says to apply around the drip line and water it in, in spring and fall for flowering and evergreen shrubs. Because the nutrients come from natural organics that soil microbes break down, results build over weeks, not days. If you have a yellowing plant that needs a quick green-up, you may need a soluble iron or sulfur product as well; see the buyer’s guide below.

Check Espoma Holly-tone 4 lb price on Amazon

2. Espoma Holly-tone 8 lb — Best for a Full Foundation Planting

Best mid-size

Why We Like It

• Identical formula to the 4 lb bag
• Enough for a row of foundation shrubs
• Fewer reorders through the season

Specification	Details
Analysis	4-3-4 with 5% sulfur
Bag size	8 lb per title; listing item count shows 2
Labeled plants	Azaleas, hydrangeas, rhododendrons, blueberries, evergreens, camellias
Ingredients note	Listing states no sludges or toxic ingredients
Application	Around the drip line, then water thoroughly

Espoma Holly-tone 8 lb — compressed specs

Once you count every azalea along the house, the hollies by the walk and the hydrangeas in back, a 4 lb bag disappears quickly, especially if you feed twice a year. The 8 lb listing is the same Holly-tone, so the decision is purely about how much you use. The title describes an 8 lb bag while the listing’s item count shows 2, so check the quantity on the product page before ordering.

Compared with the 50 lb bag below, this size is far easier to carry and store in a garage or shed, and it will not sit open for years absorbing moisture. For most suburban yards it is the sweet spot between the starter bag and bulk.

Check Espoma Holly-tone 8 lb price on Amazon

3. Espoma Holly-tone 50 lb — Best for Hedges and Large Borders

Best for big plantings

Why We Like It

• Bulk quantity for many shrubs
• Same organic 4-3-4 with sulfur
• Good for blueberry patches and hedges

Specification	Details
Analysis	4-3-4 with 5% sulfur
Bag size	50 lb
Bag dimensions	About 30 x 15 x 4 in per listing
Ingredients note	No sludges or fillers per listing
Application	Drip line, water in; no mixing

Espoma Holly-tone 50 lb — compressed specs

If you have a 60-foot holly or arborvitae hedge, a dozen blueberry bushes or a woodland garden full of rhododendrons and mountain laurel, small bags are a false economy. This is the same Holly-tone in the largest size on the shelf, nearly twice the quantity of the 36 lb bundle below and more than six times the 8 lb bag.

The catch is storage. Organic fertilizer in an opened bag can clump if it gets damp, and a 50 lb sack is heavy to move around. Fold and clamp the top, or decant into a lidded bin kept off the floor. If you will not use most of it within two or three seasons, a smaller bag is the better buy.

Check Espoma Holly-tone 50 lb price on Amazon

4. Espoma Berry-tone 4 lb — Best for Blueberries

Best for berries

Why We Like It

• Labeled for all berry crops
• Includes sulfur for blueberry pH needs
• Use at planting and for established plants
• Approved for organic production per listing

Specification	Details
Analysis	4-3-4 with 5% sulfur
Labeled plants	Blueberries, strawberries, raspberries, blackberries
Timing	At planting; established plants twice a year, early and late spring
Organic status	Registered Organic Input Material per listing
Bag size	4 lb

Espoma Berry-tone 4 lb — compressed specs

On paper, Berry-tone shares Holly-tone’s 4-3-4 analysis with 5% sulfur, and Holly-tone’s own listing names blueberries among its target plants. So why a separate pick? Berry-tone’s label and feeding schedule are written around fruit crops, which is useful if you grow mixed berries, including raspberries and blackberries that do not need acidic soil but still benefit from a balanced organic feed. If your only acid lovers are blueberries, either product works; if you have azaleas and hydrangeas too, one bag of Holly-tone covers everything.

Blueberries are the most pH-sensitive plants in this article. They need roughly 4.5 to 5.5, and fertilizer alone will not get alkaline soil there. Test first, add elemental sulfur months before planting if needed, and use Berry-tone to feed. Our guide to growing blueberries covers bed prep in detail.

Check Espoma Berry-tone 4 lb price on Amazon

5. Holly-tone 18 lb with pH Test Strips — Best for Checking pH as You Feed

Best with pH testing

Why We Like It

• Pairs feeding with pH monitoring
• Generous 18 lb bag size
• Claw gloves for working fertilizer in

Specification	Details
Fertilizer	Espoma Holly-tone 4-3-4, 18 lb bag
Extras	20 pH soil test strips, gardening claw gloves
Other	Access to a seller app assistant per listing
Seller	My Garden Pool bundle
Sulfur content	Not stated in listing

Holly-tone 18 lb bundle — compressed specs

The most common reason acid-loving plants struggle is not a lack of fertilizer; it is soil pH that has drifted too high, often because they were planted near a concrete foundation or walkway that leaches lime. This bundle pairs an 18 lb bag of Holly-tone with 20 pH test strips, which nudges you to check before you feed. Strips are a quick screen rather than a lab test, but they will flag soil that is clearly too alkaline.

It is sold by a third-party bundler rather than Espoma, and the listing focuses on the extras rather than restating the full fertilizer analysis, so read the bag itself for rates. Size-wise it sits between the 8 lb and 36 lb options. For a more precise reading, see our guide on how to test soil pH.

Check Holly-tone 18 lb with pH strips price on Amazon

6. Holly-tone 36 lb Bundle — Best Bulk Bundle

Best bulk bundle

Why We Like It

• Large quantity plus pH strips
• Granular slow-release organic feed
• Suits beds, shrubs and landscape areas

Specification	Details
Fertilizer	Espoma Holly-tone, 36 lb
Analysis	Not stated in listing
Extras	20 pH soil test strips, gardening claw gloves
Labeled use	Holly, azalea, hydrangea and other acid lovers
Form	Granular, watered into soil

Holly-tone 36 lb bundle — compressed specs

This is the bundle option for bigger landscapes: 36 lb of Holly-tone with the same test strips and gloves as the 18 lb bundle. If you want the strips, it is the bulk choice; if you do not, the plain 50 lb Espoma bag gives you more fertilizer from the brand directly.

The listing describes the product in general terms (slow-release, granular, for holly, azalea and hydrangea) and does not repeat the 4-3-4 analysis, so rely on the printed bag for rates. A sensible way to use the strips with a bulk supply is to test each bed in early spring, feed the beds that read in range, and treat the alkaline ones with sulfur first.

Check Holly-tone 36 lb bundle price on Amazon

What to Look For in a Fertilizer for Acid-Loving Plants

Low, slow nitrogen

Ericaceous plants (the heath family: azaleas, rhododendrons, blueberries, mountain laurel, pieris, heathers) have fine, fibrous roots near the surface. Strong, fast synthetic fertilizers can burn them and push soft growth that invites lace bugs and winter damage. An organic or slow-release feed with single-digit numbers, like 4-3-4, suits them far better than a high-nitrogen lawn product.

Acidifying ingredients

Look for sulfur on the label, or nitrogen from ammonium sulfate or urea in synthetic acid feeds. Nitrate nitrogen and lime-based ingredients do the opposite. Avoid fertilizers that list calcium carbonate or dolomite, and never use general garden lime around these plants.

Fertilizer vs soil acidifier

A product like Holly-tone helps keep soil acidic, but its 5% sulfur will not drop the pH of alkaline soil by a full point. If a soil test reads above about 6.5 under azaleas or above 5.5 under blueberries, apply elemental sulfur at the rate your test recommends, work it in, and retest in a few months. Sulfur is converted by soil bacteria, so it works slowly, especially in cold soil.

How much and when

• Feed shrubs in early spring as buds swell, and again in early fall in most zones. Avoid late-summer feeding in zones 3 to 6, which can push growth that will not harden off.
• For blueberries, feed in early spring and again about six weeks later, as the Berry-tone listing suggests.
• Spread the fertilizer evenly from near the trunk out past the drip line, scratch it into the mulch layer, and water well.
• Follow the bag rate; for slow organics, the common guidance is measured per foot of branch spread for shrubs.
• Skip feeding newly planted shrubs until they show new growth, unless the label says to mix it into the planting hole.

Where ericaceous compost fits

“Ericaceous compost” is a UK term for lime-free, acidic potting compost made for heath-family plants. In the US you will usually find the same idea sold as azalea, camellia or acid-loving plant potting mix, typically based on peat or pine bark. Use it for growing blueberries, azaleas or camellias in containers, and blend it into planting holes in heavy or neutral soil. It is a growing medium, not a fertilizer: it supplies structure and low pH but few nutrients, so you still feed with something like Holly-tone. Mulching with pine needles, pine bark or composted oak leaves keeps surface pH low over time.

Reading the symptoms

Yellow leaves with green veins (interveinal chlorosis) on azaleas, gardenias or blueberries usually mean iron is locked up by high pH, not missing from the soil. More fertilizer will not fix that; lowering pH will. Overall pale, small leaves with weak growth point to a genuine nutrient shortage. Our azalea care guide covers other causes, and the composting and soil hub explains soil testing and amendments in more depth.

Hydrangeas are a special case

Bigleaf and mountain hydrangeas grow fine in a wide pH range; acidity mainly changes their flower color. In acidic soil with available aluminum, flowers turn blue; in neutral to alkaline soil, they go pink. Feeding with an acid fertilizer supports blue flowers but will not shift color on its own in alkaline soil. Panicle, smooth and oakleaf hydrangeas do not change color at all.

Which Pick Fits Your Yard?

• A few azaleas, hollies or hydrangeas: Holly-tone 4 lb.
• A full foundation planting: Holly-tone 8 lb.
• Hedges, woodland beds or many shrubs: Holly-tone 50 lb.
• Blueberries and mixed berries: Berry-tone.
• You have never tested your soil: one of the bundles with pH strips, then a lab test if strips read high.