Plants for Alkaline Soil

Green Velvet boxwoodIf a pH test reveals your soil is alkaline (pH higher than 7), some plants will not thrive there. On alkaline soils certain nutrients, particularly iron, are locked up. Some plants have evolved to grow despite limited access to these nutrients. Other plants—including rhododendrons, camellias and heathers—suffer.

You may try to change soil pH with certain additives, but the results don’t last. The better option is to choose plants that like the acidity—or lack thereof—in your soil.

Those who garden on limestone or chalky soil need not despair. More plants thrive in alkaline conditions than on very acidic soil. Other pluses? Most alkaline soils drain well and tend to warm up more quickly in the spring. As with nearly all soils, it’s a great idea to add organic matter, such as compost and well-rotted manure, to alkaline soils. This will increase its ability to hold water and nutrients.

Here are some of the great garden plants that prefer alkaline soil:

Evergreen shrubs
shown: Green Velvet boxwood (Buxus ‘Green Velvet’; Zones 6–8)
Daphniphyllum himalaense ssp. macropodum (Zones 7–8)
Photinia species (Zones 7–9)
Aucuba species (Zones 7–10)
Euonymus fortunei ‘Emerald Gaity’, ‘Silver Queen’, ‘Emerald n Gold’ (Zones 5–8)
California lilacs (Ceanothus spp.; generally Zones 8–10)

Deciduous shrubs
Daphne species (Zones 5–8)
Deutzia spp. (generally Zones 6–8)
Forsythia spp. (generally Zones 6–9)
Mock oranges (Philadelphus spp.; generally zones 5–9)
Lilacs (Syringa spp.; generally Zones 5–9)
Weigela spp. (generally Zones 5–9)
Spiraea spp. (Zones 3–8)

Perennials
Hellebores (Zones 4–8)
Pinks (Dianthus spp.; generally Zones 4–10)
Brunnera macrophylla ‘Jack Frost’ and ‘Looking Glass’ (Zones 4–8)
Clematis spp. (generally Zones 3–8)
Potentilla spp. (generally Zones 5–8)
Scabiosa spp. (generally Zones 5–9)

Image attribution

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Having trouble finding plants for your Alkaline soil? Check out Chalk and Limestone Gardening and Success with Alkaline-Loving Plants for answers to alkaline woes!

Horticulture’s Smart Gardening Techniques also has tips for soil maintenance

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14 thoughts on “Plants for Alkaline Soil

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  4. I am a landscape designer who lives in Davis (Northern California) in Zone 9.Not only do we have alkaline soils but hard water, with a high concentration of boron! I have Deutzia, Spirea, Hellebores, and Clematis (several varieties) all doing well here. We do try to amend the soil slightly where we can to give plants a good start but knowing most homeowners, they won’t keep that up! So right plant, right place is the answer…

  5. I live in the West in an area with high alkaline soils and out of all the plants on the list 4, maybe 5 will grow here. Grow not thrive. On the surface, this article lacks a real life experience feel to it and is misleading. Although the caution about not wasting your time trying to change the soil pH is right on!

    • Hi, Sylvia — Thanks for taking the time to comment. I do have experience growing several of these plants, but of course not all of them. I try to write from experience plus reading. I garden in the East. Some of these plants won’t work for me due to winter cold. As we all know, a number of factors come into play on any plant’s health, but here I was just looking at alkalinity. Would you say these plants don’t thrive in your area chiefly because of the soil pH, or also the climate? We welcome readers to add their experiences and plant recommendations in this comment area, especially given the size of the US (our chief audience) and the diversity of its climates and growing conditions. What are some of your best plants for alkaline soil?

  6. I believe several of the zone ranges indicated in this otherwise helpful article are incorrect. I live in zone 4 (with alkaline soil) where Syringa, Weigela, Philadelphus, and some hardy varieties of Forsythia are common in landscapes and garden centers, including the one where I work.

    • Hi, Denise — thanks for stopping by! I struggled a little bit with indicating zones in this post because I was referencing whole genera instead of individual species. I gave just a “ballpark” range, and you’re right, there are species/cultivars that push past these limits, sometimes being bred to do just that.

  7. I live in a zone 3 area with somewhat alkaline soil. I can grow many more types of plants than zones usually indicate. Lilacs grow very well here, so zone 5 is incorrect. The plants I have that show some chlorosis are Rosa rugosa David Thompson and my amur Maples, which are still sturdy and worth having, albeit with slight leaf discoloration. I have tried Bonide Iron Sulfate, which seems to have little effect.

  8. Yes, I agree with the article and the comment posted. I would LOVE IT if all plant catalogs/books would indicate the soil preferences for each plant. Some do but many don’t.

  9. “You may try to change soil pH with certain additives, but the results don’t last. The better option is to choose plants that like the acidity—or lack thereof—in your soil.”
    - A comment worth repeating. As a design/build landscaper I see too often homeowners trying to “fight” their conditions instead of “going with the flow”. Your post about picking the right plant for the landscape is spot on.

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